Marine Insurance Services
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C31 Property Damage Appraisal
Summary Notes--2001
(Note: these notes should be used as a study aid only--and with the diagrams found in your text).

CHAPTER 1--INTRODUCTION
    To establish the extent and value of damage to property, a detailed loss estimate is prepared—through observation and notes.  The work required is determined through careful inspection, often under adverse conditions.  All components requiring repair/replacement are noted; measurements are taken.  This information (arranged & priced) becomes the working detail of the loss, and used for adjustment and negotiation.
    Objective Damage Appraisal: Estimating repairs is different from estimating new construction.  In new construction, estimates are prepared away from site using previously prepared plans.  The estimator is aware in of quantities, dimensions and components.  For repair, the estimator prepares his own specifications based on measurements, observations, and experience.  Pricing is strongly influenced by the estimator’s concept of work required.
    Many factors come into play in computing repair.  Costly demolition and haulage of debris from site is necessary.  Some damage may be concealed.  Some damage may worsen with time.  One must consider consequential repairs, e.g., repairs to basement areas may involve floor framing above.  Repairs to framing may require replacing fixtures, not directly damaged.
    Novice appraisers may simply apply unit rates for a speedy estimate.  Pricing books, employed without proper interpretation lead to inaccuracy.  Factors which can distort an estimate:
        · Location—city/town, street and distance from contractor’s shop.
        · Extent of damage within building.
        · Type of work, accessibility, and nature of occupancy.
        · Aggregate work in any trade (large quantities cost proportionately less than small quantities).
        · Ability to use labour saving equipment (confined areas may preclude this).
        · Experience and number of available local tradesmen.
        · Quality of workmanship expected--standard, good, or custom type finishes.
        · Labour employed--non-union personnel may not be permitted on certain job sites.
        · Supervision required--if several trades involved, co-ordination is necessary.
        · Working from ladders or scaffolding.
        · Availability of electrical power for heat, lighting and to operate mechanical equipment.
        · Seasonal weather conditions.
        · Disruption of repair by owners/tenants.
        · Potential disruption of repair work due to occupancy.
        · Relocating salvable stock, furniture, contents, fixtures, or equipment.
        · Protection of adjacent areas and contents because of consequential damage potential.
    Emergency Services: Additional expenses in providing emergency or temporary services:
        · Moving/removing debris.
        · Removing/protecting undamaged components, equipment, furnishings & stock.
        · Draining/protecting plumbing, heating or sprinkler systems to prevent freezing.
        · Shutting off utilities (gas, water, electric).
        · Installing emergency or temporary roof coverings.
        · Installing temporary heat or reactivating heat--for freeze-up, continued occupancy, or drying.
        · Closing in window/door openings (and other safety and security measures).
        · Removing water to reduce damage to floors and interior finishes--pumping out basements, clearing floor drains, wet vacuuming carpeting and floor—or removal of carpet/underlay.
        · Restoring power and light to prepare estimates or for normal operations of premises.
        · Washing/cleaning of buildings/contents to prevent permanent damage.
    The estimator should make written notations as soon after the occurrence as possible (conditions may alter during repairs or clean up).  Notes include anything important for adjusting the loss equitably, such as age and condition of the structure and finishes, extent and quality of previous renovations.
    It may be necessary to update various components for building code requirements.  This may include: sprinkler systems, alarm systems, fire escapes, stair enclosures, exits and entrances, fire rated doors, ceiling and wall finishes, dust collection equipment, electrical panels and power distribution systems, and structural deficiencies.  If unacceptable by local regulations, they must be improved before repaired, whether insured or not.
    Building Code and By-Laws: The National Building Code is prepared by the Associate Committee on the National Building Code of the National Research Council of Canada; minimum provisions to protect public safety with respect to structural strength, fire resistance, and health and safety aspects of buildings.  It is advisory only; no real legal standing.  Similar regulations have been embodied in provincial legislation.  An appraiser must take care to note pre-existing violations of local by-laws.  By-laws reduce the risk of fireand other damage, by reducing hazardous conditions from poor maintenance and substandard construction.
    More significant is the building by-laws, in effect in the municipality where the loss occurred.  In many provinces, the municipality has ultimate jurisdiction over construction, repairs, and renovations.  The municipality may have adopted some or all of the provisions of the National or Provincial Building Codes.  Each municipality may have a different building by-law.  The appraiser should consider the National Building Code only as a guideline to good building practice, and to determine possible areas of non-compliance with a local code.
    The agent of enforcement for most regulations is the building inspector; he is involved when a building permit is applied for-- on all repair work.  In some areas, the fire chief also has regulatory powers--especially public buildings like apartments and offices.  In certain commercial structures, one might also have to deal with the Provincial Department of Labour.
The effect of building by-laws:
        · They dictate when a building is repairable, or must be demolished.
        · They govern when a component must be renewed or not.
        · They dictate the extent of emergency repairs (i.e., closing in, reinforcing, or demolishing).
        · They provide regulations observed during construction, reconstruction and demolition.
        · They provide specifications regarding materials and construction practices.
        · They govern the use and occupancy of buildings.
        · They require permits, and the production of plans and specifications.
    Depreciation: loss in value from any cause, including obsolescence or loss in market value.  Depreciation for insurance includes wear and tear, exposure to elements, or structural defects-not obsolescence or loss in market value.  Depreciation may be curable (within control of owner by ordinary maintenance); the value of depreciation is the cost to cure such deterioration, e.g., decorations, floor coverings.   Depreciation may be incurable (actual loss in strength and remaining life, which the owner could not justifiably repair), e.g., structural framing or masonry.  In estimating depreciation, one may consider the probable life of a component and use an age life comparison for a percentage.  The condition of a complete building is considered, compared to a new building.  Comparison of condition is key, not age alone.  One also considers previous renovations, and the ability of the structure to serve its intended purpose.

CHAPTER 2--GLOSSARY OF TERMS
    Beams and Joists:  The distinction is in the relative functions of the components and their sizes.  Joists are horizontal floor framing members 10” to 24” apart, supporting flooring above.  A larger framing member on which the joists bear, is a beam.  If a beam is supported on a larger unit, it is a girder (rare).
    Posts, Columns and Piers: The distinction lies in the nature of the materials used.  Posts are vertical wood members supporting girders or beams.  If they are iron or steel they are columns, and if masonry or concrete they are piers.
    Beam: (load-bearing members) normally used to support floor joists at the basement level.  They may be steel, solid lumber, or built-up (laminated) wood.  This latter configuration for wooden beams is common today, from 6” x 8” upward.
    Sill Plate: a framing member (normally 2” x 4” or larger) lying on its flat side on top of the foundation wall, secured to the perimeter foundation by anchor bolts embedded in the wall.  This plate is the level surface and the lowest horizontal wood member to which the rest of the framing is fastened.
    Joists: the main horizontal framing members used to support floors.  Joists vary from 2” x 8” up to 2” x 12”.  Joists are set on their narrow (2”) edge, normally 16” apart, so they can bear maximum weight.  In commercial applications they may be 12” apart (centre to centre) to support extra weight.
    Bridging: refers to framing members used to bridge or tie floor joists together, reducing tendency to warp or deflect; bridging also transmits load from 1 joist to many.  Bridging may take 2 forms, 2” x 2” pieces nailed criss-cross fashion at right angles at 6-8’ intervals (cross-bridging), or pieces of the same dimensions as the joists nailed at right angles between the joists (solid-bridging).
    Subflooring: bridges and covers the space between the floor framing members and provides a structurally sound floor surface on which the finish flooring is applied.  It may be 1” thick boards (width may vary) nailed diagonally across the joists, or plywood (usually 5/8” – 3/4” thick).  The thickness and type determines the load bearing potential.  Depending on the type used, a further layer of thin plywood or other material called underlayment may be applied on top of the subfloor as a smooth base for the finish floor.
    Studs: upright framing members (normally 2” x 4” in nominal size), set vertically on end to form the interior and exterior walls.  Studs may range upward from 2” x 4” to 2” x 6” or larger, depending on the weight supported, and the height of the wall.  When gypsum lath and plaster or drywall are used, the studs are usually spaced 16” on centre.  Studs are doubled in thickness at windows and doors and tripled at wall intersections.  They are bridged or stiffened by cross-members nailed at right angles between the studs.
    Wall Plates: horizontal units of wall framing.  As the top member of a storey, the wall plate supports the floor joists of the next storey.  At the top of the upper storey, it is the roof plate and supports the ceiling joists and rafters.  As wall plates bear considerable weight, they are usually doubled in thickness (two pieces of 2” x 4” joined together, forming a laminated 4” x 4”).  Wall and roof plates are nailed to supporting studs.
    Rafter: the main framing members for sloped roof structures.  They are set on edge (on the narrow 2” edge), and form the support skeleton for sheathing and finish roof covering.  The upper ends of the rafters rest against a ridge board, and the lower ends are supported on the wall plate.  The dimension of material used will vary according to the weight of the roof, the span of the rafter, the pitch or slope of the roof, and expected snow and wind load.  Common rafter dimensions for sloped roofs are 2” x 4” and 2” x 6”.
    Ridgeboard: is the framing member which runs at right angles to the rafters at the ridge or peak of a pitched roof, to which the upper rafter ends are butted.  It is normally a 1” thick piece of material.  It aligns and provides securing of the upper ends of the rafters.
    Sheathing: sheathing spans and covers roof rafters and exterior wall studding.  Sheathing refers to the building component not the actual material; sheathing may be 1” boards (l” x 6” to l” x 12”) or plywood, gypsum board, particle board or foam/fiberglass insul-board.
    Masonry Veneers: exterior masonry is a non-load-bearing facing, tied to the frame by metal straps or wall ties.  There is a wall cavity of approximately 1” between the sheathing and the interior face of the masonry.  The function is to enclose the building, make it weatherproof, with an attractive finish, and a degree of resistance to fire.  Most common is Brick Veneer.

CHAPTER 3--STRUCTURAL TYPES
    Brick-Joist Construction: (Rare) In a solid brick or masonry structure (residential, multi-storey commercial or industrial building), the main load-bearing components are exterior masonry walls.  The horizontal framing members are set on or into these walls and on interior walls or beams.  The bearing walls may be brick, stone, concrete, concrete block or other similar materials or combination.  If plaster or other finish is used inside of the exterior masonry wall, wood members (called furring) are fastened to the inner surface, with lath and plaster, gypsum board, or whatever finish, attached to this nailer.  A waterproof building paper is applied under the furring, as a vapour barrier.  The masonry outer walls, are technically incombustible.  They can suffer damage by cracking or deflection from fire-related causes, including heat, expanding and contracting steel, and sudden cooling from firemen’s hoses.  Advantages: there are few concealed cavities in the sidewalls for the spread of fire from floor to floor.  The fire may leave the exterior walls unharmed, where fire has damaged the interior.  This resistance may be enhanced by plaster or gypsum board finishes on interior walls.  To protect exterior walls for collapse of interior framing, the ends of joists are tapered or fire-cut where set into the wall, and will fall free without disturbing the masonry above.  Disadvantages: it is necessary to apply wood nailers for attachment of interior finishes.  Repair of framing members will involve masonry repairs.
    Platform Frame Construction: employs wood stud-wall framing in which the main floor joist framing is fastened to the top of perimeter walls or foundations (via the Sill Plate) and subflooring applied to the top of the joists.  This resultant platform serves as a base upon which the walls and interior framing are erected.  When floor joists for the second floor (if any) are installed, one has the corresponding base for a second storey.  This type of construction is western or repeat storey framing.  This is used in residential construction, and sometimes in commercial, light industrial and agricultural applications.  Advantages: easy erection with minimal scaffolding and manpower.  The system can be prefabricated.  Extending the subfloor to the perimeter helps prevent fire from travelling vertically. Disadvantages: this type is more prone to movement between the wood-framing and exterior veneers.  Damage to framing can necessitate renewal of masonry veneers.
    Balloon Frame Construction: (usually two-storey residential, rare) the exterior stud wall framing extends from the foundation to the eaves, in 1 continuous run.  The framing for the second floor and ceiling joists rest on ribbon boards, nailed across and let into the interior face of the stud walls.  There are interior bearing partitions at the midpoint of the structure, providing support for horizontal framing. Advantages: relative stability and rigidity.  Disadvantages: difficulty of construction and obtaining framing members of length to rise 2 storeys.  Without wooden blocking (fire stops) placed between the long vertical wall studs, fire can travel unobstructed within the wall cavities.  Impact to the lower wall can affect entire wall and roof sections.
    Post-And-Beam Construction: structural system whose horizontal framing employs beams 3 feet or more apart, supported by vertical posts.  The beams are spanned by heavier-than-normal plank decking (or roof sheathing for roofs), forming structural floor and roof assemblies.  Wall areas may have supplementary non-supportive framing for application of finishes.  As supports are spaced wider than normal, decking must be stiffer (heavier).  Used in commercial, recreational, industrial and agricultural applications.  Some residential use is made where special effects are desired.  Advantages: aesthetic or architectural effects, economy--no further interior treatment is needed, with the functional wood members exposed and unfinished except for varnish or paint.  There is considerably less labour involved in cutting and fitting components.  This type of structure also offers freedom of interior planning.  Posts and beams instead of interior load bearing walls--creating more open space.  There is an absence of concealed spaces where fire can spread undetected.  Disadvantages: a greater than normal degree of skill and care is required in erecting this type, as the exposed framing components also serve as the interior finish.  It is difficult to conceal electrical and mechanical services.  As wood framing members are exposed, as opposed to protected by plaster or gypsum board, they are more susceptible to fire.  This type of structure offers larger spaces, which do not restrict the spread of fire.
    Heavy Timber Construction: (rare) like post and beam construction to the extreme.  Some fire endurance is obtained by using very large wood structural members, and the thickness and composition of floors and roofs.  There are few concealed spaces, particularly below the floors and roof.  1 type is mill construction.  Heavy Timber Construction is found in industrial, storage, assembly and mercantile applications.  Advantages: Fire resistance, economy of construction, architectural utility and appearance (through exposed wood members and large open bays).  There is a saving incurred by having to deal with fewer but larger framing members.  Disadvantages: a premium is paid for large dimensioned material, also longer than normal length.  Many beams are manufactured by special order, from smaller sized pressure laminated components; time can be considerable, and can influence costs if loss of production or loss of use is insured.  These buildings are difficult to erect.
    Fire-Resistive Construction:  has bearing walls of masonry, reinforced concrete, or other non-combustible materials with fire ratings expressed in minutes or hours.  Framing is reinforced concrete, formed and poured in position, or structural steel with fire resistive material--brick, plaster, or structural clay tile.  Floors, roofs and partitions are non-combustible with a fire resistance for a specified period.  Floor surfacing and trim, while not necessarily non-combustible, should not contribute to the spread of fire.  Stairways, elevator shafts, pipe chases, or floor or ceiling openings are enclosed for fire resistance.  Openings are protected by rated fire doors.  Air handling ductwork in climate controlled buildings have fire dampers to prevent the spread of smoke and fire, especially where buildings have sealed windows.  Other structures like the fire-resistive type are semi-fire-resistive and non-combustible; the fire resistance times are reduced.  Advantages:  fire is contained in a limited area and rarely causes serious structural damage.  Disadvantages: difficulty and expense in gaining access for installation/maintenance of electrical and mechanical facilities.
    Unprotected Metal Construction: structural framing is exposed or unprotected metal, sheathed in material with a minimum fire resistance.  Exterior wall cladding is non-combustible and has a fire rating of less than 2 hours.  Used in light manufacturing, storage, garage and repair shops.  Can be pre-engineered pre-finished aluminum or steel building with compatible steel siding and framing. Advantages: economical and easy to erect.  Disadvantages: non-interchangeable framing members from one-manufacturer to another.  Also, obsolescence--companies may change components or go out of business.  It is difficult to match coloured metal siding of obsolete design, or weathered or oxidized colour, without refinishing the entire building.  They are susceptible to damage from heat and fire.  They will readily deflect and distort and steel can lose its temper (structural strength).  A building may have to be substantially dismantled for replacement of 1 damaged framing member.

STUDY 4--EXCAVATION, FOOTINGS AND FOUNDATION
    Excavation: not normally insurable.  In planning the site for a building, one usually chooses undisturbed soil; areas of backfill or poor soil are avoided.  Consideration given to: the level of water table, the drainage pattern of area, the depth of solid footing material below grade, and the depth of frost penetration.  To compensate for these, excavation is necessary.  In Canada, foundations are below grade level, so they not be damaged by frost.  The depth will depend on the local climate.  Also a basement or crawl space is provided.  Even buildings with no basement usually have a trench excavation for drainage.  Excepted are buildings constructed on a floating slab, where the floor-slab is the support for the superstructure.  Very large or heavy structures may be supported on vertical piles or caissons, driven into filled ground or soil unsuitable for normal footings--for construction on hard-pan soil or bedrock.
    Footings: the widened section, usually concrete, at the base of a foundation wall, pier or column.  It is situated below grade where it cannot be affected by frost or poor soil.  Footings vary in design and application; all provide specific load bearing capabilities.  Wall footings normally take the form of a continuous perimeter concrete slab or pad, located on an excavated trench floor or perimeter of a full basement excavation.  They are also poured in the form of pads under all intermediate piers or walls.  The width, thickness, depth and strength of footings depend upon weight and the width of foundation wall.  Footing is 8” wider than the wall and a minimum thickness of 6”.  Footings are multi-leveled or stepped.  Reinforcing (rare) is required where footings are undermined (trenching for plumbing/drainage).
    Foundations: the lower supporting base of a building, used to transfer weight to the ground through footings.  Foundations consist of poured concrete or masonry.  Thickness depends on:
        · weight of the structure including contents;
        · height (head-room desired in basement/crawl space) and make-up of the foundation wall;
        · lateral pressure of earth fill on the exterior of the foundation wall.
    Concrete foundation walls: poured in metal, or other reusable forms and built up by a continuous pour method, with windows, doors, and frames set in place during pouring and keyed into the walls.  Internal bearing walls are keyed into perimeter walls.  Where concrete is poured in a large volume and considerable depth, air powered vibrating equipment is inserted into the wet concrete to eliminate voids--producing a smooth exposed face.
    Concrete block foundation walls: the block is laid directly on the footing and built up, course-on-course, to desired height.  Strengthening is needed to permit load bearing on the top of the foundation wall.  The top course will usually be finished either:
        (a) The block cavities are filled with mortar to make a solid top course.
        (b) The wall is capped with a 2” layer of solid masonry (clay brick) or concrete.
    Frame or masonry-veneer houses: the floor and wall framing is anchored to the foundation wall.  Anchor bolts are bedded into the top course of the masonry, with the threaded ends extended to the sill plate.  This plate (normally 2” x 6”) is pre-drilled, positioned, and bolted to the foundation wall, forming the base for structural framing to attach.
    Parging, Waterproofing and Drainage: With hollow concrete block foundations, the exterior wall is coated with cement plaster parging material, ¼” thick.  This provides a smooth surface for application of damp-proofing or waterproofing materials, and seals cracks or faults in the face.  Without this parging, a crack below grade could permit water to enter the foundation via the block cavities, and may permit water inside the building.  Chronic moisture can result in deterioration from frost, efflorescence and decay of mortar and masonry.  On the external surface of foundation walls, a coat of bituminous (tar or asphalt base) material (damp proofing) is applied to protect against ground moisture.  If there is a head of water, (a lot of ground water under pressure) this treatment is inadequate and waterproofing is needed--2 or more layers of membrane are mopped onto the wall and coated with bituminous material.  Some water will normally accumulate around a foundation.  To carry this away, a clay weeping tile or perforated piping is laid outside the wall, leading into a sump or collection tank, or to the municipal storm drain.  This tile is covered with 6” of crushed gravel, with a ¼” joint separation.  After parging, waterproofing or damp proofing and drainage, the foundation is ready for backfill to grade level.
    Damage: Footings, foundations and drains are not normally damaged by fire.  The upper sections of foundation may be damaged by heat.  Collapse of framing or expansion/distortion can damage block work.  Thermal shock from cooling by firemen’s hoses can cause cracking or spalling.  Frost action can cause heaving and cracking.  This can happen when interior temperature falls below freezing.  Without heat in the basement, frost can penetrate the soil beneath and heave footings from inside.  Concrete floors are susceptible to heaving by frost--especially if soil is wet.  Some protection is afforded with temporary heating facilities, or spreading straw over the basement floor and against foundation walls.  Washouts from ruptured water service can occur under footings and foundations, producing cracking and settlement, and plugging (by displaced soil) of drains.  Concussion or vibration damage from blasting or construction is rare, as soil is a poor conductor of shock waves; if the footing is poured on bedrock--damage is possible.  Impact by vehicles or other objects can occur.  Damage can occur at the point of impact, and also at remote points.  Deflection/partial collapse of structural walls during backfilling is another source of loss.  Fuel oil seepage: escaping oil from underground storage tanks or buried piping may break down the petroleum based water-proofing of the foundations.  Oil contamination can also destroy lawns, trees, shrubs and plants.  The first course of action is to eliminate the source of seepage.  In repairing, the foundation may be excavated and re-waterproofed, plus extra drainage installed.  In extreme cases, replacement of the affected masonry is necessary.  Leakage from gasoline tanks can gather in drains, and create a hazard from explosion and fire--dictating expert and immediate action.  The Fire Department would perform water and chemical flushing of drains.  Airing of enclosed areas and extinguishing all open flame and electrical elements should done.  Blockage or breakage of rain water leaders below grade may permit water into foundations, and accelerate depreciation.  Settlement or subterranean shifting of foundation support may produce cracks, and entry of ground water.  Improperly mixed mortar, poor mortar material, or mortar applied during freezing may have poor adhesion in foundations, and minor disturbance may cause widespread cracking.  Repair: simple cracking of foundations at mortar joints is curable by pointing or refilling of the defective mortar joints.  Walls which have been deflected, by vehicles, lateral pressure of earth, etc., are excavated and rebuilt from the lowest point of deflection.  Parging and waterproofing are restored.  It’s important to examine conditions indicating depreciation, deterioration, or ageing.  Properly installed footings on sound subsoil, and well-constructed foundations, should last indefinitely.  3 potential areas of depreciation:
        · Settlement-- cracking at mortar joints or through masonry.
        · Mortar deterioration from poor material or constant exposure to moisture.
        · Failure of damp proofing, waterproofing, or drainage (discoloration of masonry units, efflorescence, dampness, or running water).

STUDY 5--MASONRY AND CONCRETE
    Masonry: stone, brick, or other earthen products for the erection of structures, generally using mortar as a bond.
    Mortar: composed of portland cement, hydrated lime, and sand;  powdered, premixed (1 unit cement, ¼ unit lime, 3 units sand) compound--one adds sand and water.  Mortar may be coloured to coordinate with masonry.  Importance of good mortar:
        · It helps bind masonry into a strong, integrated, stable and permanent structure.
        · It effectively resists ready passage of moisture.
        · It compliments the masonry in providing a colour coordinated, pleasing appearance.
    Masonry varies; choice depends on structural and aesthetic requirements.  5 types:
        · Concrete Block          ·  Concrete Brick              ·  Clay Brick
        · Natural Stone             ·  Structural Clay Tile
    Concrete blocks: sand, portland cement and an aggregate (sand, crushed stone, slag), in nominal widths of 4, 6, 8, 10 and 12 inches.  They are 8” high and 16” long in face.  Sizes are nominal; actual measurements are 3/8” less in each dimension--for mortar joints.  Specially shaped blocks are used to reduce time in cutting and fitting and for a uniform finish when part blocks are required--corner blocks, half block, jamb blocks and headers.  Decorative textures are available.  2 weights are common, standard and light.  Standard weight blocks contain aggregate (sand or crushed stone) and weigh 40-50 pounds per unit in 8” width.  Light weight units contain less dense aggregate (haydite) and weigh 30 pounds--used where load-bearing strength of supporting structures is critical.  Concrete blocks are normally hollow, with 3 air cells, to form a continuous-cell arrangement when joined.  Blocks may be used as structural back-up with other facing materials (brick, stone or wood siding).  Block is the main structural unit for foundations and load-bearing basement partition walls.  It is used in supporting piers--where concentrated load bearing strength not required.  Blocks are used as main partition walls in structures as a fire-break--separating attached stores or apartments.  Quantity of block required is calculated by multiplying the face area by 1.125.  Damage: Concrete blocks resist heat, except where fire is intense or prolonged--then the face is prone to crumbling from dehydration, and will crack.  Mortar joints resist heat less than blocks.  Block walls have little lateral strength and may collapse where lateral forces are excessive.  By-laws require lateral reinforcement in certain structures, to prevent collapse from explosion, weight of debris, or expansion of steel framing.  During construction, poorly supported masonry wall panels may be blown down in windstorms.  Concrete blocks are susceptible to smoke and melting roof coverings, and their surface may be marked by impact.  Repair: damaged blocks can be replaced in limited areas; it may be necessary to enlarge the area of repair for keying-in to the wall.  Where internal reinforcing is added, the repair is extended beyond the damage to maintain structural integrity and design.  Damage to unfinished block by smoke or staining does not respond well to cleaning as the face is porous and absorbs the stain.  Heavy sandblasting damages the face, so light sandblasting and painting is necessary.  Steam cleaning or washing of unsealed surfaces may drive the stain further into the block.  Where only mortar is damaged, repointing (chipping out and reapplying mortar) may be possible.  There may be problems matching decorative blocks of obsolete styles or sizes—sometimes it is possible to transplant undamaged block from an inconspicuous location.  Depreciation: improperly designed walls or poor workmanship can result in defects (bulging, cracking, and deterioration) allowing moisture to penetrate the walls and invite frost.  Un-repaired impact damage, poor maintenance, or unnecessary exposure to the elements can result in loss in value.
    Brick: a manufactured masonry unit with dimensions approximately 8” x 2¼” x 3¾”.  The 8” length may vary to 11½”, and the 3¾” dimension may vary to 5¼”.  The key measurement is the 2¼” face height.   Terminology:
        1. Brick Bat: A brick unit of full dimension.
        2. Breaking Joints: The pattern created by laying brick, eliminating continuous vertical mortar joints (staggered joints).
        3. Chase: A vertical or horizontal recess in a wall--to conceal pipes, ducts, and wiring.
        4. Control Joints: Vertical joints (filled with resilient material) at places where stresses might occur--as in the middle of large masonry panel.  This is usually built into a wall for controlled expansion and contraction (from temperature changes).
        5. Coping: A building component which forms a cap or finish on top of a masonry wall, pier, pilaster or chimney--may be cast concrete, clay-tile or metal.
        6. Course: A horizontal layer or row of brick, block, or other masonry unit.
        7. Header: A masonry unit laid with its end-face exposed and spans 2 or more adjacent wythes or layers of masonry to tie them together.  Exposed headers are a clue whether a wall is solid masonry or veneer facing.
        8. Lintel: A supporting horizontal beam set in place over a window, door, or other opening in a masonry wall to support masonry above.  It can be steel, wood, or reinforced concrete, depending on the size of opening and weight.  In older brick or stone structures, a masonry arch may be used instead.
        9. Pilaster: A widened section of wall projecting at intervals from either or both faces of masonry wall--serves as a vertical pier, supporting the wall and bearing for beams.
        10. Stretcher: A masonry unit laid with its long dimension parallel to the masonry wall face.
        11. Wythe: A continuous vertical section or layer of masonry 1 unit in thickness.
    Concrete bricks are manufactured like other concrete products and were popular as facebrick during and after WW2.  There were problems with lack of uniformity, colour, and moisture resistance--recently improved.  Recently, one finds larger than standard sizes--Roman and Norman types.
    The most common brick is clay brick.  These vary by manufacture, texture, size, and colour; 2 categories: common brick, and face  brick.  Common Clay Brick (red pressed brick) is used for back-up (unexposed to view or weather) in solid masonry walls, or protection of structural components (steel).  It is not treated for texture, colour or hardness.  Face Brick is especially made for facing, has surface textures (bark face, antique) and varying grades for anticipated use and weathering resistance.
    There are types of clay brick for specialized uses--Special types:
        · Fire brick                       · Glazed brick
        · Acid resisting brick         · Paving brick
    Fire Brick (refractory brick) is used to line fireplaces, boilers, and chimneys; Glazed Brick is used for decoration or ease of cleaning and maintenance.  Acid Resisting Brick is used for floors of chemical plants, etc.  Paving Brick is very dense, and used for driveways, etc.  Bricks are bonded together in a variety of ways, creating patterns.  2 common bonds are running bond (bricks are laid with the long edge exposed) and common bond (every sixth vertical course is laid with brick ends exposed--a header).  Other bonds are Flemish, English and Stack.  The number of bricks to repair a face-wall area is determined by multiplying by 7.  The absence of header courses in a brick wall may identify a veneer wall, other patterns may indicate a solid masonry wall.  Damage: extent of damage depends on:
        (a) the thickness of the wall                    (b) the quality of the brick used
        (c) the quality of workmanship used       (d) the length of duration of exposure
        (e) the general age of the wall
    Thin walls suffer damage more readily then thick walls, and soft brick more than hard brick.  Poor mortar, lack of mortar, or old and deteriorated mortar, makes walls more susceptible.  Concrete and common clay brick are more porous and prone to un-repairable damage than clay brick.  Fire or heat damages brick by causing the surface to spall, especially from cold water from fire hoses.  Thermal expansion from heating causes cracking in individual bricks and in the wall; if brickwork is old or inferior, collapse can result--particularly when lateral pressure is applied by falling debris, force of hoses or expanding or contracting steel.  Smoke residue is common, as is staining by chemical agents or asphalt from roofing materials.  Water damage is not common except where freezing or staining is involved.  Freezing, particularly in the freezing and thawing cycle, will cause spalling.  Brick structures are subject to damage by impact, explosion, vibration and other mechanical injury.  Depending on the type of brick and bond used, damage can extend beyond obvious surface damage--cracking and deflection of entire masonry panels or walls.  Repair: removing damaged sections and replacing with new.  A problem is matching the colour and type of brick and mortar; transplanting brick from an inconspicuous location may work.  Cleaning stained brick may be possible; several methods--acid or detergent chemical cleaners, steam cleaning, or sandblasting--treatment is usually extended over entire building elevations or panels for a uniform appearance--spot cleaning is often not acceptable.
    Depreciation: good original quality results in long-lasting structures.  However, cracking, spalling or bulging of brick are evidences of depreciation.  Owners may be unaware of the deteriorated brick until something unusual occurs, like vibration from nearby blasting or construction, or impact.  One must determine the pre-existing condition of the brick and estimate the expenditure to return it to reasonable condition for its age.  There are no set depreciation factors.
    Natural Stone: limestone, sandstone, granite, marble and flagstone.  Stone is used as facing material not a load-bearing component.  Stone facings utilize fastenings to tie them to supporting structures.  Sealant compounds have replaced mortar in some installations.  Cut stone is used in window sills, copings, and ornamentation.  Crushed stone of various kinds and colours is used as a decorative and weather-resistant facing.  It can be added to wet concrete to expose the stone, or secured to a slab by adhesive.  Damage: same problems as manufactured units.  Depending on porosity and hardness, stone will respond better to cleaning.  Stone may be damaged by staining, heat and mechanical injury.  The backing material, framing, sheathing, or backup masonry units may be damaged.  Usually, depreciation of stone is not significant, but failure of bonding material, mechanical ties, or mortar is.
    Structural clay (terra cotta) is manufactured like clay brick.  It has a variety of shapes, sizes and uses.  It may be custom moulded.  It is commonly standard partition tile, and shaped to enclose structural steel for fire protection.  It is used as coping on masonry walls, or as back-up material for brick or stone.  Damage, repair, and depreciation factors are like clay brick.
    Concrete: (not “cement”) mixture of portland cement, sharp sand, and an aggregate mixed with water.  The aggregate can be natural stone, crushed stone, etc., depending on properties required (weight, hardness, weathering resistance or expansion).  Ratios required vary by application--commonly 1 part cement, 2½ parts sand and 3 parts stone aggregate.  It may be formed with steel rod or mesh reinforcement--without reinforcement where stresses are in compression (footings and foundations)--with reinforcement where tensile stresses are involved (beams and floor slabs above grade).  When poured, wet concrete must be contained--such as by wood or metal formwork.  Cost estimates for concrete work include:
        1. Forming                                                                         2. Reinforcing - if applicable
        3. Pouring                                                                          4. Stripping of forms
        5. Finishing--steel trowel, wood float or cement wash.
    Damage: Concrete has good fire resistance due to its moisture content and slow rate of heat conductivity.  Poured concrete ceilings and walls (underground garages) can spall or flake due to heat; structural damage to floor slabs by heat is rare.  Heat damage to other concrete components can vary from smoke staining to surface spalling, cracking, and breakdown.  Damage by smoke or other staining, and cleaning methods, are like that with unit masonry.  The absence of heat after a fire can permit frost penetration through the concrete to the subsoil and cracking through upheaval.  Methods of repair may involve:
        1. Removal of damaged concrete sections or loosened/cracked surfaces.
        2. Cleaning and preparation for bonding of the new material--and a bonding agent.
        3. Installation of new forms and reinforcement.
        4. Pouring and finishing of new concrete.
        5. Stripping of forms.
    Depreciation: concrete exposed to frost, hydrostatic pressure, undermining by water, vibration or upheaval, can suffer substantially.  Other structural concrete components are immune to much depreciation except by severe weathering.

STUDY 6--CARPENTRY-FRAMING
    Scope of Work: distinction between rough and trim carpentry is not defined; rough carpentry includes:
        > Concrete form work
        > Framing for walls, floors and roofs;
        > Window and door frames (rough openings);
        > Sheathing and subflooring;
        > Furring and plaster grounds;
        > Sleepers and strapping;
        > Temporary hoarding--stairs, wood scaffolding;
        > Fencing, porches, other yard fixtures
        > Structural hardware (joist hangers, anchor bolts, framing fasteners)
    Milling and Measurement: lumber grades are used to classify lumber into categories, each with a narrow range in specifications.  This system is based on the number, type, location and extent of defects.  Grading also defines milled lumber sizes.  Typical grades are “select”, “construction”, “utility”, “economy” and “stud”.
    Pricing: Most lumber is priced by the linear foot or the board foot.  In large quantities, price may be in dollars per thousand board feet.  From the time it is surveyed in the forest until installed in the building, price increases with the steps in processing--cutting, haulage, milling, retail.
    Board foot of lumber is 12” x 12” x 1” thick.  The board feet in a length of wood is obtained by multiplying the width in inches by the thickness in inches and dividing by 12, then multiplying by the length in feet.
10 feet of 2” x 3” lumber equals 5 board feet.           (2 x 3 x 10) = 5
                                                                                      12
    Board measure: used when computing cost of lumber for repair or replacement, and is be determined by factoring linear footages: 2 x 4 (.667), 2 x 6 (1.0), 2 x 8 (1.33), 2 x 10 (1.667).
    Nominal dimensions of lumber do not represent actual size (a 2 x 4 is not actually 2” x 4”).  Due to material shortages, cost increases and changing building codes requirements, actual dimensions have been reduced over time.  Actual sizes of dressed lumber are standardized--actual sizes in nominal 2” thick material are diminished by ½” (a 2” x 4” is actually 1½” x 3½”).  Dressed lumber is ordered by its nominal size.  The shortage in dimension from nominal to actual is milling waste.  Typical waste factors range from 10% for 1” x 12” to 28% for 1” x 4”.  Lumber comes in standard lengths.  Cutting waste arises, as available lengths do not always fit the end use (a rafter may be 10’ 6”, but is cut from a standard 12’ length).  Cutting waste will involve 3-5% on linear materials and 5-10% on sheet goods (or plywood).  Plywood, ten-test and other sheet materials are priced by square foot, usually in 4’ x 8’ sheets.  Larger sheets are available, but by special order which may take weeks or months.
    Framing and Wood Types: In choosing a type of wood, consider:
        1. Strength and rigidity
        2. Ease of working (cutting, machining)
        3. Ease of fastening and ability to take fastenings without splitting
        4. Resistance to weather
        5. Dimensional stability (freedom from shrinkage and expansion)
        6. Freedom from objectionable defects such as knots, splits, and heavy gaining
        7. Ability to take finishes
        8. Resistance to wear in abrasive situations (door sills and flooring)
        9. Resistance to decay under frequent exposure to moisture
        10. Pleasing appearance when finished
        11. Cost
        12. Design requirements.
    No one type of wood is superior in all these qualities, one has to determine the most important requirements for the job. Coniferous trees (evergreen) supply most lumber used in framing--these are softwoods.  Common types are pine, spruce, fir, and cedar. Deciduous trees are hardwood--used where resistance to wear is required (floors, stair treads, thresholds, cutting boards), and for custom quality doors, trim and wall paneling.  Common types are birch, poplar, maple, ash, oak and elm.
    Spruce: relatively inexpensive, light in weight, moderately susceptible to shrinkage--good strength, stiffness, toughness and hardness, and easily worked.  Spruce is the most common framing and sheathing lumber.  It is best suited for protected situations--when exposed to the elements or moisture it will decay and warp.
    Pine: lighter in weight and lower in strength but straighter, clearer grained, more weather resistant and more easily worked than spruce.  Pine is fairly expensive—its use in framing is restricted to applications where appearance, freedom from warping, or weather resistance are critical.  It is found in door and window framing, where it can withstand exposure to the elements.  It is used for exterior fixtures, like porches and stairs.  Similar weathering qualities at a lesser cost can be achieved with cedar.
    Douglas Fir: the strongest of the hardwoods.  2” x 8” spruce used in flooring will span 12’; fir will span 13’ 8” in similar configuration.  It is however, hard, heavy and tends to split and check, and does not lend itself to painting.  It is used in plywoods and factory-produced laminated beams.  It is more expensive than spruce.
    Fastenings: no structure is stronger than its joints and fastenings.  The most common fastening for wood is the nail.  Nails and spikes come in many lengths, diameters, configurations, materials, finishes and coatings--each designed for a specific purpose.  In Canada, nails are specified by the type and length in inches, ranging from 1/3” to 6” (nails), and 4” to 14” (spikes).  Framing spikes are used in the ratio of 10 lb. per 1000 FBM (Foot board measure) of 2 x 4 (9 lb. for 2 x 6, 8 lb. for 2 x 8).  The National Building Code of Canada or the Canadian Code for Residential Construction determines required types, lengths, numbers and spacing of nails in framing applications—but do not cover all situations, and good common sense is needed.  Rule of thumb: if 2 members are being nailed together, the nail should be double the length of the thickness of each member.  Other forms of fastenings:
        · H-clips or staples--to connect sheathing or subflooring to wood framing.
        · Threaded anchor bolts--for fastening sill plates to foundation heads set in masonry.
        · Joist hangers or saddles--to connect and support joist framing where it intersects headers.
        · Split-ring connectors--used with nuts and bolts, in heavy timber construction to protect against slippage of abutting members and splitting at holes drilled to receive bolts.
    Damage: wood is combustible unless treated; it will ignite at between 212°F and 460°F.  The rate of burning depends on density of the wood, its moisture content (normally 15-18%), its dimensions, and amount of oxygen.  When wood is exposed to heat (not actual burning) it loses moisture content by evaporation, and may shrink, check, split, or char.  Such damage can be superficial, or lead to structural weakness.  Actual burning can vary from minor charring to complete consumption.  Repair techniques:
        > Complete replacement
        > Partial replacement
        > Refinishing
        > Reinforcement
        > Surface Treatment
    Replacement of damaged framing members may require replacement of undamaged items (repairs to roof framing may involve shingles).  To determine if a structural member requires replacement, one has to consider many factors.  The first, is the depth of charring or burning.  Although the surface may be charred, the wood below can retain its strength.  The strength of a member 2” or more thick will not be substantially reduced by 1/8” of char.  The allowable depth of char depends on the size and use of the component.  Appearance should be considered--for naturally finished members, a satisfactory appearance after a fire can be impossible to obtain.  Where appearance is not critical, sealing with paint is sufficient.  It may be necessary to cover the affected area with a material like gypsum board.  All charring must be removed before surface treatment is applied.  Replacing part of structural components is the next consideration—for laminated wood beams, only 1 leaf may be seriously charred.  It might be practical to replace only that leaf.  To determine the practicality of any approach, one considers the costs of each method including shoring, involvement of adjacent items, and requirements of by-laws.  Reinforcing or laminating may be used where adjacent or contiguous items are not damaged but would otherwise be renewed.  A cost saving can be obtained, but appearance may be affected.  An example would be the renewal of upper roof rafters, leaving lower sections with attached soffit undisturbed.  Resurfacing by sanding is sometimes satisfactory.  Surface charring of heavy timber may respond well to sandblasting, if depth of char is not critical and structural integrity not jeopardized.  Damage from lightning can be minor or severe.  It can result in damage like that from explosion and fire.  It is unpredictable as to force or manifestation, as is the path it may take from contact with a building to the point of exit.  When lightning strikes, it may fan out, often through natural conductors (wiring or piping); a structural inspection is necessary, which may reveal damage to joists and rafters at remote points.  Lightning may cause a resultant fire. Repair: lightning damage repairs are like those with fire.  There may be dislocation of members, not just charring.  Disturbance of fastenings may have occurred.  For most other types of framing damages, the same considerations are used--governed by by-laws and good building practice.

STUDY 7—INSULATION AND MOISTURE CONTROL
    Insulation: any material that has a relatively high resistance to the transmission of heat.  It may take any form from Styrofoam to sawdust.  Functions:
        1. It provides economy of fuel consumption.
        2. It provides more uniform indoor temperatures both summer and winter.
        3. It can increase the fire rating of wall or ceiling structures.
        4. It may be used to control sound transmission.
    Insulation types:
        1. Loose fill (mineral wool, glass wool).
        2. Batt or blanket (mineral wool, glass wool).
        3. Reflective (aluminum foil).
        4. Insulating boards (fibreboard, cork, foamed plastic, polystyrene and polyurethane).
    Moisture Control: water vapour within a structure is created by cooking, bathing, laundering and other activities.  This vapour is dissipated through windows, doors, walls and ceilings with little evidence of its passage.  When outside temperatures are low, water vapour will sometimes not pass entirely through walls or ceilings but will condense within the wall cavity or roof space on a chilled surface.  This is a cause of exterior paint failure, and decay in framing members and exterior wall coverings.  Insulation may contribute to condensation as it induces heat loss: the temperature of the wall on the cold side of the insulation (within the wall cavity) will be lower than if no insulation were used; the temperature in the wall cavity may be below the dew point.  Installing insulation in old houses can result in damage, due to decay of wood framing members from moisture.  It is desirable to reduce the passage of moisture to the wall cavity--accomplished by a vapour barrier.  A vapour barrier is an impervious sheet material in the paper liner of batt type insulation or attached independently on the warm-side of the insulation (inside face of the unfinished stud wall).  This material (polyethylene) has a high resistance to water vapour.  A vapour barrier limits condensation by creating an air seal at the interior surface of the wall or ceiling.  Another means of controlling condensation is proper ventilation of attic and soffit spaces.  Damage: Aside from direct destruction, damage to insulation occurs as a result of smoke or water.  Most forms of insulation retain smoke and often have to be replaced.  Smoke odour removal services can sometimes be successful.  When subjected to water, insulation may lose its effectiveness and hold moisture, causing damage to adjacent materials.  Loose wool insulation is often lost on removal of the supporting material.  Many rigid forms of insulation are combustible and others change their forms from heat or fire.  Reflective insulation is also damaged by heat and fire and mechanical injury (perforation or tearing).  Vapour barriers create an air seal, which when broken reduces their effectiveness.  A puncture (mechanical damage) requires material replacement over a large area.  Vapour barriers are also susceptible to damage by heat or fire.

STUDY 8--TRIM CARPENTRY AND MILLWORK
    Finish carpentry: all carpentry not including framing or structural carpentry.  Finish carpentry is open to view, needing more skill: windows, doors, casings, baseboard, paneling, cupboards, cabinets, stairways, finish hardware, wood siding, wood shingles, and exterior trim.  Millwork: finish carpentry involves millwork, including components of finished wood and manufactured in millwork plants and planing mills.  It includes doors and frames, windows, cupboards, trim and mouldings.
    Wood and Materials Used: depend on properties desired:
        ·  Appearance--texture, grain, color and free of defects.
        ·  Capacity to take finish.
        ·  Machinability and ease of working.
        ·  Ease of nailing and ability to hold fastenings.
        ·  Freedom from excessive shrinking or swelling.
        ·  Resistance to wear and marring.
    Finish carpentry utilizes softwoods and hardwoods.  Some softwoods are harder than hardwoods (Douglas fir is harder than basswood).  Hardwoods (deciduous trees) include:
        · Oak--for interior flooring and trim.  Oak is heavy, hard, stiff, strong, resists abrasion, but not easily worked.
        · Birch--for interior trim, doors, flooring and plywood paneling.  Birch is heavy, hard, stiff, strong, has a fine uniform texture, takes a good natural finish, and is high in shock resistance.  It is low in decay resistance and tends to warp in storage.
        · Poplar--for planing mill products and plywood.  Poplar is straight-grained and of uniform texture, holds fastenings well, finishes smoothly and easily worked.  It is light, soft and weak.
        · Maple--for flooring.  It is heavy, hard, strong, stiff, resists moisture, wears well under abrasion, suffers only moderate shrinkage, and has uniform texture.
        · Basswood--for trim, cabinets, shelving and good quality panel doors.  Basswood is light in weight and low in strength, soft textured, straight-grained, and easily machined.
Softwoods (coniferous or evergreen trees) can be similarly classified under trim materials:
        · Pine--for window sash and doors (different species are used in framing trim work.)
        · Cedar--for siding, shingles and exterior trim.  It is light, weak, soft, and splits readily.  It has a fine and uniform texture and resists to decay.
        · Redwood--for sash, doors, siding and exterior finish trim.  It is light, strong, durable, resists decay and takes an attractive finish.
        · Mahogany—for trim, casings, door facings and paneling.  Not readily classified as hard or softwood.  Many qualities--Philippine (soft), Honduras (hard).  Trim mahogany is easily worked, economical in price, and finishes well in natural tones.  Mahogany is marked by water, abrasion or smoke and not easily refinished.
    Plywood: common building material--composed of 3 or more layers or skins laid with alternate grain directions (one layer at 90° to the next one) and machine bonded with glue.  Plywood normally comes in 4’ x 8’ sheets.  It is manufactured in 2 classes--Hardwood and Softwood.   It is manufactured in 2 grades—Interior and Exterior (exterior grades bonded with waterproof glue).  Most softwood plywood is Douglas fir and used in rough carpentry, not finish work.  Hardwood plywood comes in a larger variety of species.  All types come in different grades, sizes, and thicknesses.  Plywood gradings:
        · Good 2 sides--each face is composed of a single piece of veneer and free of defects--used where natural finish is desired on 2 sides (cupboard or cabinet doors).
        · Good 1 side--one face is free of defects, but the back can be 1 or more pieces of veneer, well joined and reasonably matched for grain and colour.  Some neatly made patches are acceptable on reverse side.
        · Sound 2 sides--free of open defects with neat patches permitted on both sides.
        · Sound 1 side--face as described, but back may have knotholes not larger than 1” in diameter and other defects that will not impair serviceability.
        · Sheathing--solid surface but permits 6 knotholes 3/8” or less.  Permits splits in veneer up to ¼” in width plus 1 or 2 strips of patching tape and any number of plugs and patches.
        · Industrial--2 solid faces of 1 or more pieces with open defects repaired & lightly sanded.
        · Concrete Form-Exterior--like above, but requires sealing of edges and faces for a smooth non-absorptive face.
    Windows: components:
        ·   Frame--perimeter unit attached to the wall framing unit to which the sash is fitted.
        ·   Sash--part of the window into which the glass is fitted, moveable or immoveable.
        ·   Trim--casings and mouldings bridging gaps between the window frame and wall finishes.
    Horizontal framing members are rails and vertical members are stiles.  Trim used to restrict movement of doors or window sash within frames is stop mould.  Types of windows:
        · Double hung--vertical sliding sash by-passing in the frame
        · Casement--sash hinged to the side of the frame and swinging outward
        · Awning--sash hinged to the top of the frame
        · Hopper--sash hinged to the bottom of the frame
        · Sliding--sash sliding horizontally in the frame
        · Jalousie--sash pivot, like louvres within the frame
        · Fixed--sash secured permanently in the frame
        · Sashless--glass secured directly in outer window frame, moveable or immoveable.
    Window joints: types:
        · Simple butt joints
        · Rabbetted joints
        · Housed joints
    Sash joints: types:
        · Mortise and tenon joints
        · Dovetail joints
        · Slip cover joints
    Woods Used in Windows: pine is used mostly; also redwood, fir and cedar.  Wood may be treated with a preservative. Damage: Windows and frames are susceptible to fire, heat, impact and water damage.  When wooden sash are damaged by fire or broken, new sash (and glass) may be installed without replacing the frame.  The sash may be repaired by replacing parts; care is taken with the cost feasibility--compared with installing a new window unit.  In removing frames, one must consider repairs to adjacent plaster, trim, caulking, and flashings.  Consideration of consequential repairs is important.  Another factor is the necessity to renew storm sash and screens.  Also considered is the feasibility of substituting aluminum or steel windows in place of wood--this may appear to be betterment, but may be cheaper.  The factors in estimating the cost of windows:
        · Size, shape and type of window unit.
        · Number of lites and grade of glass.
        · Thickness and quality of sash.
        · General quality of materials and workmanship.
        · Wall construction—which determines additional work required.
        · Type, amount and quality of hardware.
        · Availability of stock or standard replacement sizes.
        · Necessity to match the design or configuration of adjacent windows.
    Depreciation: the most common enemy is moisture leading to decay.
    Doors: 3 components: the door, its frame, trim of some type.  Types of interior and entrance doors:
        1. Slab - hollow core
        2. Slab - solid core
        3. Panel doors
        4. Louvred doors (slatted)
        5. Folding doors (accordion type)
    Method of installation or hanging:
        · Hinged (standard)--hinged on 1 side
        · Bi-fold (hinged in the middle and sliding to 1 side of the door opening)
        · Pocket (hanging on a track and sliding into a wall cavity)
        · Sliding (by-passing on a track or hangars)
    Aside from buying, trimming and hanging a door, time and expense are involved in repairing the frame.  Exterior doors normally have a rabbetted frame or jamb, (nominally 2” thick) to which the door is hung without additional trim.   This jamb may be bedded in a concrete sill or wood sill and fastened to the exterior wall framing.  Interior doorframes employ nominal 1” thick jamb material for trim is application.  4 Types (Wood Doors):
        · Slab-Hollow Core—Inexpensive, light core (wood or paper board) with choice of plywood facings in both stain and paint grades.  More economical to replace than repair: even though only slightly charred, difficult to refinish due to thin facings and light construction.  They are easily damaged by smoke, water and physical injury.
        · Slab-Solid Core--Solid laminated lumber core with variety of veneer and plywood facings, more expensive than hollow core.  Solid Core Doors are difficult to refinish in stain grades, but due to increased costs, repair may be attempted.  Solid core doors are susceptible to water, but is sometimes constructed with waterproof plywood facings.  Solid core doors are used as entrance doors and they are more resistant to impact and water.  They are more readily repairable, but care is used to determine cost advisability.
        · Panel--Often custom-made doors constructed from Pine, Cedar, Fir, Oak and Redwood.  They have solid lumber rails and stiles, jointed and glued with decorative or plain inserts or panels.  They may be glued.  They used to be common.  Interior panel doors are custom made and expensive.  They are used in exterior applications, in stock sizes.  Panel-doors can be disassembled, and new parts installed--shop produced.  This avoids the expense and time to have doors custom made, or where substitution of a stock door is not possible (custom quality or odd-sized applications, or where exotic woods are used).
        · Folding or Bi-fold--May be slab or louvered.
    Doors are manufactured in stock sizes.  A problem exists (old houses) with doors of non-stock dimensions.  Custom-made doors are costly, and involve waiting periods of 6 to 8 weeks.  Repair costs and techniques depend on:
        · Type of door--hollow, solid, panel                        · Material--pine, mahogany, basswood
        · Size stock or custom                                            · Hardware used--stock or custom quality
        · Ornamentation or detailing in the door panels        · Type of installation
        · Type of finish required
    Depreciation: doors are damaged through wear and tear, and insured perils.  Joints can open, surfaces can check and stain, and hardware may wear through use and abuse.
    Exterior Trim and Cladding: items of exterior trim are ornamental and functional.  They must resist weathering; woods used are pine, cedar, fir and redwood.  They include components of soffit and fascia, siding, cornice and other mouldings.  They include prefinished metal (aluminum) or asbestos siding.  Damage: exterior trim and cladding are subject to usual perils, but more exposed to physical injury or abuse.  They may require repair or replacement from damage to supporting components.
    Repair: 5 problems encountered:
        · Matching--Cladding and mouldings may be difficult to match in pattern or dimension, even ordinary-looking wood clapboard siding.  These were often made by specific mills, for limited periods.  Sizes and specifications are not standardized.
        · Involvement of adjacent areas--One may find it necessary to replace larger areas or more items than actually damaged.  It may be necessary to remove entire sections of cladding to repair a single piece—especially with metal siding.
        · Decay—Framing may decay (including by termites or dry rot, and may be obscured), and it is impractical to attach new facing material or trim.
        · Sub-standard Construction--such conditions may preclude restoration:
                o undersized or over-spaced framing (attachment of modular materials difficult).
                o siding not properly secured to its underlying framing.
        · Access Problems—Scaffolding may be required for repairs or replacements at higher levels, especially if large areas or handling of cumbersome materials is involved.
    Depreciation: mostly due to lack of proper maintenance; one may encounter unrepaired damage from prior losses.
Interior Trim: commonly encountered items:
    Casing: Window and door frames are usually edge-trimmed with matching wood moulding called casing, available in a variety of sizes, patterns and species of wood.  Casing joints are mitred and may be glued to resist opening of the joints, when normal shrinkage occurs.
    Base moulding: a finish at the seam between the wall and the floor--in a variety of sizes, patterns and woods.  They are thick enough at the bottom to cover the seam at the edge of the floor, high enough to cover the bottom edge of the floor, and high enough to cover the bottom edge of the plaster finish.  The most common base trim, is the two-piece baseboard, with shoe mould (quarter round).  A single member combination base is also used.  The corner joints in baseboard are coped and butt-joined or they may be mitred on exterior corners, which can be time consuming for a proper fit.
    Wall moulds: cornice or ceiling mould, dado or chair rail, or wall mounted handrail in a stairway, picture or plate rail, interior and exterior corner mould and panel-mould.
    Panelling: products ranging from economical prefinished plywood panels to elaborate and expensive solid plank panelling.  4 classifications:
        · Printed prefinished panelling (3/6” in thickness)--plywood or pressed composition board.
        · Veneered prefinished panelling (1/4” in thickness)--plywood.
        · Genuine wood veneer on platewood or plywood (¾” in thickness).
        · Genuine solid wood planking (3/4” or more in thickness).
    Many species of wood are used in interior trim; common are pine, mahogany (soft) and oak.  Damage: Wood trim can be easily damaged by fire or water.  The smaller a cross section of wood, the greater the susceptibility to moisture.  Trim readily warps, cups, checks, and shrinks.  Damage by heat and smoke depends on the finish--paint, varnish or oil--natural finishes are more damageable.  The major problem in repairing is matching.  Various sizes and patterns exist, so unless recently manufactured, it is no longer a stock item.  There were and are many manufacturers, each milling different patterns, and some woods previously used are no longer available (gumwood) or very expensive (walnut). Various options available in dealing with repairs to damaged trim:
        · Renew all trim (even undamaged portions) in a room with stock trim--often most economical.
        · Where little trim is required, transplant from an area (closet) where it will not be obvious and replace the material removed with stock trim.
        · Have the material specially manufactured to match.
        · Patch and refinish.
    Errors in estimating are made if attention is not paid to the style of trim or type of wood--substitution of cheaper and new types or styles is not always acceptable.
    Stairs: components:
        · Stringers--the long side members on which steps are set.
        · Treads (steps).
        · Risers--vertical sections between the treads in housed stair installations.
    Oak and pine are common woods in stairs.  Oak is used for interior treads for its appearance, strength and wearing qualities.  Pine is used for secondary interior stairs and exterior stairs as it is straight grained, stable, decay resistant, and finishes well.
    Damage: stairs open on the underside are more damageable by fire, due to the flue-like action of openings, and relatively thin members of the staircase.  Building codes require that fire-retardant covering be placed on the underside of stairs in public or commercial buildings.  Stairs are less apt to char on top, except where burning materials fall onto them.  Water is a cause of damage, resulting in marring, checking, and warping; repair methods:
        · Replacement: consider adjacent items such as wall finishes and trim.
        · Replacing parts: possible, confined to treads, risers, balustrades, wedges and blocks.
        · Re-surfacing by sanding may be acceptable where damage is slight, such as smoke staining.  With oak, staining from water can be deep enough that replacement is necessary.
        · Reinforcing and Concealing: may be practical where the underside of the stairway is slightly charred, and structural strength not jeopardized; one may remove char, reinforce the stringers and cover the stair soffit on the underside with gypsum board--very important--this is not to hide damage, but to provide a pleasing appearance and increase fire resistance and occupant safety.
    Depreciation: stairs are prone to loss of value from normal wear and tear:
        · Actual wearing of treads through long use.
        · Loosening of treads, risers, or railings.
        · Shrinkage and dislocation of fastenings.
        · Decay--principally in basement and exterior stairs.
        · Marring, scoring or scratching of tread surfaces through abuse.
    Stairs vary in terms of replacement cost, ranging from simple open-string pine steps to winding oak stairways.  Stairs are priced by the tread and type, and in custom configurations they are shop-produced by specialists.
    Finish Hardware: hinges, latchsets, cabinet pulls, closet hardware.  Aside from the quality of manufacture and materials, the cost of hardware can vary by design (standard or custom) and finish.  Common types of finish:
        · Wrought iron      · Cadmium        · Brass          · Nickel
        · Bronze               · Aluminum        · Chrome      · Copper
    Variations of these finishes: brushed, bright, antiqued, satin or dull.  Depending on quality, design, and finish, latchsets range from $7.50 to over $100.00.  Damage, Repair and Depreciation: subject to heat, smoke, water, impact and breakage.  Solid metal hardware may be removed, cleaned and reinstalled; cheaper plated or lacquered units will not.  Repair depends on quality, type, age and extent of damage; replacement of broken or defective parts is possible on better quality units.  Factors considered in repair:
        · Availability of matching replacement units.
        · Degree of speed required in carrying out replacements.
        · Amount of wear or abuse suffered (new units are more repairable).
    Unless a unit is expensive and exact matching is essential, repairs to hardware are rare.  One could transplant from an inconspicuous area.  Depreciation can occur by wearing moving parts (hinge pins, lock mechanisms), normal use and abuse or lack of maintenance.  Physical inspection is used to assess depreciation; no age-life table is used.
    Cabinets and Counter Tops: methods and materials in producing cabinets, vanities, and other millwork have changed.  They were previously built in place by carpenters, but now mostly shop produced and finished; they were constructed of dimension lumber, but now made of plastics, plywoods and particle-core products and veneered with wood or plastic laminates.  Counter tops have changed in style and type from the old units built on site using ceramic tile, linoleum, metal and sheet plastic laminated with chrome trim.  Current tops have a wider range of design, with built-in compound curves and corners.  Factors influencing cost of counter tops include: length, number of joints (corner mitres), number of finished ends, quality of laminate and cross sectional configuration (standard or custom width, face edge, and back detail).  Damage, Repair and Depreciation: old and modern types of cabinet and counter-top are affected by fire, heat, smoke and water.  Repair or replacement are different.  Linoleum and ceramic tile counters and splash backs (old style) are difficult to match, and are replaced.  Removing a damaged ceramic tile top is costly.  Replacement of ceramic tile counter surfaces by plastic laminate units, requires alteration to the base cabinets.  Linoleum is inexpensive and easy to replace with new but similar materials.  Of importance in smoke damaged counter top is immediate cleaning.  Smoke damage, left for an extended period, will cause permanent shadowing or staining of plastic laminated counter tops (from acids in smoke residue) necessitating replacement.  A problem in repairing the older style built-in-place cupboards, is that every component is secured in place--to the walls, floor, ceiling and each other.  It is difficult to remove, repair, and reinstall any part.  With modern kitchen cupboards, the units are easily removed and replaced.  For entire kitchen installations, one can purchase prefinished modular-replacement units.  There are problems with these latter units:
        · The finish is factory-applied of a special material.  Matching of the finish is often impossible, even by the original manufacturer.
        · Doors and ornamentation are ornate and difficult to reproduce, and the hardware may have been specially purchased on an end of line basis, impossible to duplicate.
        · Plastic laminate on doors or cabinets may be repaired, if matched (difficult).
    Where damage to a counter top is localized, a substitute section (wood cutting board or ceramic counter saver) can sometimes be installed--otherwise replacement for minor burns is necessary.  A problem with plastic laminate tops and cupboard units, is difficulty matching colour and pattern.  Depreciation: wear and tear to cabinets is usually minimal.  The newer finishes are more durable.  Lack of maintenance result in decay of the wood structure and warping of doors; other abuse may be loosened or missing hardware and defacement of doors.

STUDY 9--LATH AND PLASTER
    Lath and Plaster: interior finish with 1+ layers of gypsum compound over lath base, and a thin layer of lime material (putty), for a smooth, white finish.  Plaster was for 2000+ years, and still used, though drywall more common.  Plaster provides freedom of design, durability, and fire protection.  It requires time for drying, and can hold up other trades.  The base must have a good bond or key.  Types of base: gypsum lath, expanded metal lath, wood lath (obsolete).
    Gypsum lath is fire resistant, and rigid, with a gypsum core.  It is covered with heavy absorbent paper.  It comes in sizes of 16” by 48” and thicknesses of 3/8” to 1/2” depending on spacing of the framing.  Gypsum lath is the most common base, is economical, controls cracking and crazing, and speeds up plastering (only 1 base-coat required).  It is unsuitable for exterior use or where exposure to moisture expected.
    Expanded metal lath (diamond mesh) is made of galvanized or painted steel.  It comes in sizes of 27” by 96” and 24” by 96”.  It may be bent and used for ornamental work.  Metal lath is rarely used in residences because of high cost and 3+ coat application.  It is used for curved work, applying cement plaster, or for a fire rating of 3+ hours.  It is used to reinforce critical areas (corners of door openings or the middle of large ceilings) to prevent shrinkage cracking.
Additional surfaces where plaster may be applied:
        · Unit Masonry--concrete block, clay or gypsum tile.  Masonry is wet down prior to plastering to reduce removal of moisture, which hinders curing and bonding.
        · Concrete--must be free of foreign matter and loose particles.  It must be rough to provide a proper key—or a bonding agent is applied.
        · Polystyrene and Polyurethane--requires wire mesh at all joints when used in areas over 80 square feet to reinforce against shrinkage when drying.
    Base Plasters and Accessories: Finished plaster has 2+ layers of plaster over lath.  Base coats require 4-5 days to dry; a quick-drying agent may be used.  The first coat is hardwall, bonding plaster, or cement-lime plaster.
        · Hardwall plaster is a general-purpose gypsum plaster to which an aggregate is added.  This aggregate is sand, wood fibre, perlite or vermiculite.  Hardwall is most common.
        · Bonding plaster is a mill-mixed plaster used over concrete.  It provides maximum bonding to concrete without adhesives.  It is found in fire-resistive structures.
        · Cement lime plaster (stucco) may be mixed with sand for exterior use.  It is applied over sand-cement plaster on wire lath and is found on frame or masonry buildings—and not finished with lime plaster.
    In lath and plaster, reinforcing materials may be used at points of structural weakness or potential injury.  Some accessories:
        · Cornerite--expanded metal lath used to reinforce internal angles.
        · Cornerbead--expanded or perforated flange types, used to form and protect exterior corners.
        · Striplath--reinforces seams where different materials abut at corners or openings.  It consists of strips of expanded metal lath.
    Finish and Ornamental Plaster: the final surface treatment for lath and plaster.  It is the visible plaster surface which is trowelled over the basecoat.
    Lime putty is produced by slaking or soaking quick-lime in water, requiring 3 weeks.  Hydrated lime can be used instead, requiring 12 hours to slake or cure.  To enable the lime to cure, a hardening agent is added--gypsum (gauging plaster or plaster of Paris), 3 parts lime to 1 part hardening plaster.  Fine silica sand may be added, providing a denser finish and reduced shrinkage.  This putty coat is applied in a thickness of 1/16” to 1/8”.
    Keene’s Cement is almost pure gypsum plaster--its water of crystallization driven off at high temperature.  It is powdered and has a strong accelerator (hardening agent).  Keene’s cement is applied before the base plaster has dried.  Keene’s cement is not waterproof, but is a dense and resists moisture absorption.  It may be used in damp locations.
    Other special types of plaster finish: acoustical plaster, textured plaster, and stucco.  These are factory-mixed with only the addition of water needed.  Permastone is added for finishing of exterior buildings--with the appearance of natural stone or brick.  Stone facings can be repaired by replacing stones—but permastone is only repaired by renewing entire sections.
2 kinds of Ornamental or decorative plaster accents: Run-in-place (formed at the jobsite) or cast (formed in moulds and attached in place by mechanical means).  Run-in-place ornamentations are used as cornices (between ceiling and wall).  A rough wood base is installed around the edge of the ceiling.   Plaster is trowelled over this base.  Cast work utilizes the same moulding plaster.  The plaster is cast in gelatine moulds and backed with jute or burlap.  It is installed by wire fasteners, screw nails, or adhesives, or set in wet plaster.  In repairing running cornice, a matching template is required.  Undamaged ornamentation may be saved--by cutting around decorative portions and replacing the damaged lath and plaster.
    Damage: physical properties of plaster: gypsum rock is crystalline calcium sulphate.  When ground into powder and heated, gypsum releases water.  By re-adding water, a workable fluid is created (wet plaster).  During setting or drying, water recombines to form crystals and the gypsum hardens (crystalline state).  Gypsum releases this water when heated--resisting fire.  The water absorbs heat and converts to steam.  The unexposed side of gypsum remains cool until all the water is driven off.  The more gypsum contained, the better it resists fire.  With prolonged exposure, the surface becomes chalky, flakes or spalls off and finally crumbles.  Plaster that is cooked from the face-side will show widespread hairline craze-cracks.  Fire can damage lath quickly--wood lath ignites, metal lath distorts, and the paper on gypsum lath burns.  The plaster face may appear sound, but be damaged from behind.  The sign of failed backing material is cracking--especially at lath joints.  Water damage: gypsum plaster in sound condition can withstand a single soaking.  Water will soften plaster, but when properly dried it will harden.  Repeated or prolonged wetting can deteriorate plaster or gypsum lath.  Wood lath when soaked will expand and contract, breaking the key or bond holding the plaster.  Additional water damages:
        · The weight of water soaked into lath and plaster can cause loss of adhesion of plaster with the gypsum lath or break the key with wood or metal lath.  Both lath and plaster may separate from wood framing.  Nails will release, and the entire ceiling may fall.
        · Water can cause adjacent framing or wood lath to swell, twist or warp.
        · Water can deteriorate the lath--rusting of metal lath, or delamination of gypsum lath.
    One may encounter localized cracking.  Lath and plaster are subject to internal and external stresses--due to expansion and contraction of framing from temperature and moisture.  External stresses may be from structural movement, or an insured peril (fire, water, impact or vibration).  An additional cause of cracking may be deflection.  Flexibility in floors, due to wide joist framing, could cause a ceiling to crack.  Plaster will crack from settlement at weak points (doors, windows, archways).
Cracking is frequent where plaster abuts a dissimilar material.  Genuine fire, or impact is not normally restricted to structurally weak areas.  In a fire, pre-existing cracks normally contain smoke residue.  Damage by smoke may be superficial, and may only require cleaning, sealing and redecorating.  Lath and plaster finishes are repairable but repairs are extended to sound surrounding surfaces--evident upon removal of damaged sections.  This removal may loosen adjacent sections--especially acute with wood lath.  For repairs to plaster over wood lath, water may cause expansion of wood lath.  Even with wire lath, the lath continues to absorb moisture and expand after plaster has set.  It may not be necessary to remove lath and plaster before installing new, especially in sound ceilings.  New lath is applied overtop, avoiding ripping out old plaster and dust proofing adjacent areas.  The cost of repairing lath and plaster depends on the number of applications, size of repair, job conditions and availability of utilities (water and light).  Wire lath, fibre-board lath, concrete, perforated lath and unit masonry require a 3-coat application with drying periods between each (scratch coat, brown coat, finish coat).  Application over gypsum lath requires 2 coats.  A small repair requires the same equipment and preparation as a large job--making any unit rate risky.  Confined areas are more time-consuming to work in.  Depreciation is difficult to assess and considered on an individual basis.  Lath and plaster of good quality and not abused, could last for the life of a building.  Depreciation depends on observed condition, not on any age-life expectancy table.

STUDY TEN--DRYWALL
    In wet conditions, gypsum board and gypsum lath disintegrate--especially if water gains entry through the ends or back of the material, and may not be remedied with normal drying.  Drywall may be more susceptible to permanent water damage than lath and plaster.  Drywall is not as prone to shrinkage or cracking.  Cracking or injury from an insured peril is easier to determine.  Drywall is repairable as sheets can be replaced.  It is impractical to repair a part of a sheet; areas involved will be larger than with lath and plaster.  Another problem occurs in matching a factory finish.  Depreciation: common problems:
        · Ridging of the seams     · Defective joints
        · Nail spots (shadows)    · Nail popping

STUDY 11--ACOUSTIC TILES AND CEILING SYSTEMS
    Acoustic tiles vary in size, shape, finish and composition.  Acoustic tiles absorb sound, and are a decorative treatment for ceilings. Types:
        · cellulose fibre                         · mineral fibre
        · perforated asbestos cement    · perforated metal
    Surfaces may be perforated, fissured or textured.  Suspended or grid-type systems may be fire-rated or non-combustible.  Fire-rating depends on the method of installation and composition.  A rated system contains metal grid, non-combustible tile and clips to hold the tile in the grid.  Methods of installation:
        · Glue-on--glued to existing or new surfaces such as plaster or gypsum board.
        · Mechanical fastenings --stapled or nailed to wood strapping or gypsum board.
        · Suspended Systems--installed in various grid systems.
    There are furred and suspended ceilings.  Furring is light framing to secure wall or ceiling finishes, where existing structural members are not suitable in type or spacing for attachment.  Suspended ceilings have the furring suspended below the structural members--does not only apply to t-bar track and lay-in acoustic tiles.  Damage, Repair and Depreciation: Except for fire-rated, non-combustible, metal and asbestos cement types, acoustic tiles have a low ignition point and subject to burning, scorching, and heat damage.  Manufacturers recommend that tile not be used in areas of high humidity—as they are susceptible to water.  Physical injury: acoustic tiles are fragile and mar easily.  Acoustic tiles are easily damaged by smoke, as they accumulate smoke and smoke odour.  All types may be stained by heat and water, and glue-on types can loosen or fall due to weight of water, drying out of adhesive, or disintegration of the tile.  Repair: it is difficult to obtain matching tiles.   Painting may be successful.  Most tile may be painted, and there is acoustical paint available.  Patterns or perforations may be damaged by paint.  It may be possible transplant tiles from inconspicuous areas.  Depreciation: acoustic tiles are easily marred and stained.  They require periodic cleaning, and are subject to humidity and condensation.  If painted prior to a loss, the type of paint will determine the practicality of repainting.  Depreciation is assessed on observed condition basis.  Metal grid systems can depreciate from exposure to moisture (rusting), mechanical injury, or poor suspension.
    Textured/Acoustical Ceilings: A common decorative application in ceilings--“swirl” or “sponge” texture finish.  Damage is not repairable on a “localized basis”.  Ceilings may be scraped and retextured in their entirety with a “bonding” agent.  More common is a spray-texture “stipple” finish.  This is decorative and has acoustical properties.  Damage to ceiling installations can occur from smoke and water.  Smoke can cause discolouration.  Painting may be attempted.  For a soft or porous texture, a “crushing” effect can occur--ruining the appearance.  Absorption of large quantities of paint is probable.  The cost may be substantial compared with scraping and retexturing.  Water tends to damage small areas.  Consideration in any repair, must be given to the size of the repair, the condition of the rest of the ceiling and demands of the owner.  Localized spray-texture repairs are only carried out to newer ceilings or where “areas” conceal any “seam” between old and new applications.     Depreciation: spray textured ceilings accumulate airborne contaminants and discolour—otherwise, the texture should last as long as the ceiling.

STUDY 12--PAINTING AND DECORATING
    Paint: any liquid material which when spread in a thin layer, solidifies into a film that obscures the surface on which it is applied.  Paint is composed of fine powders (pigment) that provide colour, and hide the underlying surface.  The pigment is dispersed in a liquid vehicle (binder) that holds the pigment to the surface, and a solvent used to dissolve the binder and to adjust its viscosity.  The amount of pigment effects the gloss--the more pigment, the less gloss, as smoothness is more impaired.  High gloss paint, though more washable than flat paint, can accentuate imperfections in the surface, so that more careful preparation is necessary.  Cheaper paints use an over-pigmented formulation where pigment is not wetted uniformly--resulting in good coverage, but poor washability and flexibility.
    2 classifications of paint: Solvent or oil based and water based.  Oil-based paints have little resistance to chemicals or water.  Where heat or humidity are severe, oil paints fail by blistering, cracking or peeling.  The binder in oil paints is oil (such as linseed oil) that dries by oxidizing in the air.  Varnishes are clear resin-containing finishes that dry by chemical reaction and solvent evaporation.  They are harder and more abrasion resistant than oil paints.  Varnishes are unsuitable for exterior wood, as they transmit ultra-violet light which deteriorates the binder and attacks the wood.  Enamels contain pigments dispersed in varnishes or resins, and dry by chemical reaction and solvent evaporation.  They form smooth hard films.  Some high gloss finishes are soft and prone to marring.  Enamels have poor coverage and require a flat undercoat to hide previous colours and provide a key for the gloss finish.  Water-based coatings: commonly Latex (rubber-based paint) paint--made of the same chemicals used to make synthetic rubber, in different proportions.  Latex paint is water dispersed not water-soluble--the binder is latex.  Latex paints resist blistering because of their high permeability; they can be applied on damp surfaces.  They require higher temperatures for application.
    Other newer binders used are alkyd, acrylic, epoxy, polyester, and urethane.  Primer sealers: used on unpainted walls and wallboard and porous painted walls before application of gloss and semi-gloss enamels.  They may raise the nap on drywall surfaces producing a rough finish.  Undercoats are used on woodwork and walls with minor surface irregularities.  They are highly pigmented and thick in texture.  With exterior painting, one must contend with moisture.  Wood swells with high humidity or when wetted.  Exterior paint must be able to withstand to this—or will fail by cracking, peeling and flaking.  Oil paints lose extensibility upon weathering and chalk.  Blistering can result from moisture.  Alkyd type paints are rarely used for exterior work since they cannot be applied over previous coats of oil paint.  In repainting it is necessary to prepare the surface by removing all dirt and oil and blistered paint.  Care is taken to remove old material from adjacent areas, for sufficient adhesion.  Adequate preparation may be more time-consuming than painting.
    Paperhanging: do not install new wallpaper over existing wallpaper; reasons:
        · Paper retains smoke odour.
        · The paste used in applying new paper can loosen the old, and may separate from the wall.
        · Many papers stretch when wet and shrink when dry and can loosen the old paper.
    In estimating cost of paperhanging, consider the cost of stripping old paper and preparing wall surfaces.  Walls may be washed, sanded, filled and have a coat of sizing applied (special adhesive-type base brushed onto the walls).  Wallpaper is purchased by the single or double roll (a single roll is 36 square feet) less waste from cutting and matching--actual coverage is about 30 square feet per single roll.  There is a big range of prices; so ‘shop around’.  Depending on material and manufacturing, costs are $5.00 to over $100.00 per single roll.  Since wallpaper is removed by water or steam, problems develop where paint is applied over wallpaper, as paint seals the surface.  Where wallpaper is installed on wallboard or drywall, it is difficult to remove without damaging the drywall or wallboard.  Vinyl papers are installed with adhesive and are more easily removed.  They are expensive to replace.  They are washable and do not absorb smoke readily.  They are cleaned more easily.
    Damage: paint and wall coverings are readily damaged by insured perils, and wear and tear or abuse.  Flat paints will not respond well to cleaning; semi-gloss and gloss paints may.  The initial treatment for smoke damage is washing.  After washing, some discolouration may still exist.  1 coat of paint may suffice over a minor smoke condition.  Severe discolouration may need 2 or 3 coats, including a stain seal.  For minor repairs, touch-up painting of affected areas may be sufficient.  Paint colour and finish may be matched with on-job mixing, but even in touch-up work whole walls or panels are done.  One cannot usually do spot decorating without repairs showing as a patch.  In assessing cost of repairs, consider job conditions:
        · Accessibility of the work area.
        · Amount of furniture to be moved, removed, or protected.
        · Amount of preparation necessary.
        · Number of windows and number of panes per window.
        · Number of colours used, and custom mixing.
        · Number of closets, amount of shelving, doors, or trim.
    Depreciation:  observed condition is more important than pure age.  Decorations that are well maintained (electrically heated homes, suffering little abuse), will last several times longer.  Decorations exposed to tobacco smoke, excessive cooking residue, small children, or pets, deteriorate quicker.

STUDY 13--GLASS AND GLAZING
    Glass is a non-porous, non-absorptive solid material made from silica and other materials.  It resists abrasion and scratches, is fatigue-proof, and has a low coefficient of expansion.  There are 2 types of glass in construction:
        · Flat glass--includes plate glass, float glass and sheet glass.
        · Pressed or moulding glass—includes glass blocks-- moulds press glass into shape.
    Ordinary flat or sheet glass is made by drawing the molten glass vertically from the vat to form the finished sheet.  No foreign substances touch the surface until it cools, so glass is smooth, reflective and unmarred on both sides.  This is the least perfect, least expensive, and most common form of glass.
    Plate Glass (polished plate glass): made by pouring molten glass from vats and rolling it onto large tables.  The surfaces are then ground and polished by hand.  Float glass is similar, but after molten glass leaves the melting tank, the semi-solid ribbon of glass is floated on molten tin and cooled.  The resultant glass is brilliant and unmarred.  Float glass is cut, inspected and packed for shipping.  The elimination of grinding and polishing reduces costs.
    Pattern Glass: Previously common-- being phased out; some patterns are still available.
    Vitrolite:  an opaque structural glass of various colours for store fronts, interior and exterior walls, splashboards, bathrooms and kitchen walls.  It looks like ceramic tile, but comes in larger sheets.  Vitrolite is obsolete and no longer available.  One may find this material in store fronts—if damaged, some other treatment is necessary.
    Thermal Windows: 2 panes of glass separated by a stainless steel channel creating an air-space between the panes.  Construction is done under controlled temperature and humidity, and panes are hermetically sealed for dry, clean air in between.  The unit is protected by a stainless steel perimeter panel.  Thermal windows reduce heat transfer from 1/2 to 2/3 of normal windows.  Thermal windows may use tinted or sun reflective glass.  Thermal windows carry guarantees of 5-10 years.
Damage: fire or heat could break this seal.  Depreciation is applied by viewing the condition of the frame, track and hardware.
Steel sash windows are common.  The old putty is hard to remove and this may be time consuming.  If windows are glazed from outside too high (high rise buildings) for ladders or scaffolding, a swing stage may have to be used from the roof—increasing costs.  Modern high-rise buildings may have window framing designed to be glazed from the inside.  Since these buildings have large lites of glass, special problems arise:
        · Elevators may be too small to carry the pane of glass.
        · Narrow or winding stairways may prohibit carrying glass inside.
        · Office partitions may be built right to the inside face of the window.
        · False ceilings may be lowered to cover the top part of the window.
    Some very large towers stock replacement glass—reordering could involve overseas shipments and mismatch.
Aluminum windows in modern apartment buildings are economical, simple and easy to install and repair.  The glass is bedded into the frame by putty tape, for a watertight seal.  A vinyl locking strip keeps the glass in place from the inside.
    Measuring the size of glass: rule of thumb is to measure the glass visible and add ½ inch to each dimension.  This allows ample material to bed and secure into the sash.
    Store Front Systems: Older wooden storefronts were often covered with sheet aluminum and trimmed with metal mouldings.  Repairs were time-consuming—involving cutting and fitting.  It is not now economical to repair.  Another obsolete system is the sash and gutter type, with the sides and top of the glass secured by aluminum sash fixed to the wood framing.
    Replacement parts are not available, and damage requires updating the storefront.  Modern storefronts use extruded anodized aluminum framing.  5 colours: clear anodized, light bronze, medium bronze, dark bronze and black.  The framing and fittings are stock items.
    Tempered and Other Types of Safety Glass: Under the Hazardous Products Act it is offence to advertise, sell, or import a new glazed patio door, shower door, bathtub enclosure, entrance door, or storm door unless glazed with safety glass.  Types available: Tempered Glass, Laminated Glass, Wire Glass, and Plastics.  Tempered glass is the most common.  It is economical, and stronger--more resistant to breakage.  Since it cannot be cut after tempered, manufacturers rarely produce custom sizes.  Small orders are expensive and delivery may exceed 12 weeks.  Cost: the change to tempered safety glass has increased cost by 30%.
    Glazing: the operation of fitting and securing panes of glass into sashes.  Wood sash windows were used in residential construction, but because wood requires painting periodically, and because they may swell and become difficult to operate, the trend is to sashless sliders and plastic and aluminum sash.  Glazing in wood sash seems simple, but involves the sealing of the sash with shellac or paint, and installing a putty bed.  The glass is secured to the sash by points, and then putty is applied and trimmed.  Often omitted in estimating costs, is the necessity to clean out old putty, glass, and fastenings and prepare the sash for reglazing--often a bigger job than the glazing.

STUDY 14--ROOFING
    Roofing is any material applied to the exterior surface of a roof (to the sheathing, decking, or framing) to make it weather-tight.  Terms:
        · Square--100 sq. ft., roofs are measured in terms of squares.
        · Pitch --slope of a roof--a ratio of rise to run (4 in 12 means 4” rise in 12’’ of run).
        · Pitched Roof--roof having sloping planes (not a flat roof).
        · Hip --outer angle (more than 180º) between 2 intersecting slopes.
        · Valley--reverse of the above (intersecting slopes at less than 180º).
        · Shingle --a thin, small unit of roofing (asphalt, asbestos, slate, or wood) in overlapping layers.  Shingles are used on sloping roofs with a minimum slope of 4 in 12.
        · Roll Roofing-- felt based roofing material impregnated with asphalt and frequently surfaced with granular material--packaged in roll form.
        · Built-up Roofing--overlapping layers of bituminous saturated roofing felt cemented together with hot pitch or asphalt and frequently surfaced with gravel or slag.  Such a roof may have from 3 to 5 layers or plies of roofing felts.
        · Metal Roofing--various types of metals, thicknesses and configurations--commonly in corrugated sheets.  It may also be plain sheet metal--custom-cut, fastened, and joined.
    Residential Roof Structural Types:
        > Gable Roof
        > Hip Roof
        > Gambrel Roof
        > Mansard Roof
        > Flat Roof
        > Shed Roof
        > Special or Custom Design
    Commercial or Industrial Roof Structural Types:
        > Flat Roof
        > Monitor Roof
        > Saw Tooth Roof
        > Special or Custom Designs
    Agricultural Roof Structural Types:
        > Gambrel Roof
        > Shed Roof
    Wood Shingles: wood used: western red cedar (most popular), redwood, and cypress--all are decay resistant.  They come in varying grades and costs according to pattern of grain and defects.  Thicker grades are shakes while the thinner and poorer are packing shingles or shimming shingles and not for roofing.   Wood shingles are machine-sawn or hand-split and are 16 to 24 inches long and 2 1/2 to 16 inches wide.  They are tapered from 1/2 inch to 1 inch at the butt end to 1/16 inch at the thin end.  They are installed with a 4 to 7 inch surface exposed and nailed to wood sheathing on battens, using rust-proof nails.  This roofing is vulnerable to fire.  Staining or creosoting improves fire resistance a bit.  Fire-proofed wood shingles are available but rare on account of high cost.
    Asphalt shingles are the most common residential roof material, made of heavy felt (paper, wood fibre) saturated and coated with asphalt, and have slate embedded in the top surface to form a water resistant and attractive surface.  They come in various sizes, shapes and colours--the most common size being 12 inches by 36 inches, with 3 tabs.  They are packaged 3 bundles to the square.  They are classified by weight in pounds per square.  The most common are 210 pound shingles (1 square of material weighs 210 pounds).  235 lb shingles are used where more durability is required.  Most shingles are self-sealing, with adhesive on the tabs atta