Glossary of House-Building Terms

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More terms will be added as we continue
 

-A-

ABOVE GRADE
A term applied to any part of a structure or site feature that is above the adjacent finished ground level.

ABUTMENT
A structure designed to receive a thrust, such as the supporting structure at either end of an arch or bridge.

ACCESS HATCH
See hatch.

ACID SOIL
See soil.

ACTIVATED CARBON
A form of carbon made porous by special treatment making it capable of absorbing various odours and vapours.

ACTIVE SOLAR ENERGY SYSTEM
A system which requires the importation of energy from outside of the immediate environment: eg, energy to operate fans and pumps.

ADFREEZING
When water in the foundation and the adjacent soil freeze together, bonding the structure to the heaving ground.  As the ground heaves, the foundations of unheated spaces like garages also move.

ADOBE
A sun dried, unburned brick of clay (earth) and straw used in construction.    Adobe is used primarily in the Southwest United States.

AERATION
The introduction of air into soil or water.

AEROSOL
A gaseous suspension of small particles of a liquid or a solid.

AGGREGATE
A coarse material, such as gravel, broken stone or sand, with which cement and water are mixed to form concrete. Crushed stone is usually designated as coarse aggregate and sand as fine aggregate.

AIR BARRIER
Material used in the house envelope to retard the passage of air.  A good vapour barrier can fufill both functions and is then called an air-vapour barrier.

AIR CHANGE
The replacement of one complete house volume of air either by natural or mechanical means.  Measured in air changes per hour.

AIR CHANGE PER HOUR (ACH)
A unit that denotes the number of times a house exchanges its entire volume of air with outside air in an hour. This is generally used in two ways: 1) under natural conditions and 2) under a 50 Pascal pressure difference.

AIR-CONDITIONING
See heating.

AIR-DRIED
A condition of lumber resulting from seasoning under natural atmospheric conditions.

AIR DUCT
A pipe, tube or passageway for moving air, normally associated with heating, ventilating, and air conditioning.

AIR-ENTRAINED CONCRETE
Concrete in which air in the form of minute bubbles has been occluded during the mixing period as a result of the use of an air-entraining agent as an admixture.

AIR FILM
The layer of air next to a surface, such as a glass pane, which offers some resistance to heat flow.

AIR GAP
See plumbing terms

AIR LEAKAGE
The uncontrolled flow of air through a component of the building envelope itself, when a pressure difference is applied across the component. Infiltration refers to inward flowing air leakage and exfiltration refers to outward flowing air leakage.

AIR LOCK ENTRY
A vestibule sealed by a second interior door.

AIR POCKET
A space or void created by trapped air which accidentally occurs in concrete work or in a pipe.

AIR SEALING
The practice of sealing unintentional gaps in the building envelope (from the interior) in order to reduce uncontrolled air leakage.

AIR SPACE
A cavity or space in walls, windows or other enclosed parts of a building between various structual members.

AIR-SUPPORTED STRUCTURE
A structure consisting of a pliable membrane which achieves and maintains its shape and support by internal air pressure.

AIR-TIGHTNESS
The ability of a house envelope to resist infiltration and exfilitration of air.

AIR-VAPOUR BARRIER
See air barrier

AIRWAY
The space left between roof insulation and roof decking to allow free movement of air.

AIR WELL
A space within a building, enclosed by walls, partially or totally open to the outside air at the roof, and intended solely as a means of ventilation for bathrooms, kitchens and service rooms.

ALBEDO
The reflectance of solar radiation for a given surface is referred to as the albedo rate.

ALTERATION
Any building change that does not alter the total volume.

ALTERNATING CURRENT
See electrical terms

AMENDMENT
A substance added to a soil to improve its physical properties such as texture, as opposed to fertilizer which is added to improve chemical properties.

AMENITY AREA
An area or areas within the boundaries of a project intended for recreational purposes which may include landscaped site areas, patios, common areas, communal lounges, swimming pools and areas used for similar purposes.

AMPERE
See electrical terms

ANCHOR BOLT
A steel bolt used to secure a structural member against uplift.  It is usually deformed at one end to ensure a good grip in the concrete or masonry in which it is embedded, as with the bolts securing a wooden sill plate to a concrete or masonry floor or wall. 

ANGLE BEAD
A small moulding placed at an external angle formed by plastering surfaces in order to preserve the corner from accidental fracture.  Also known as corner bead.

ANGLE IRON
An L-shaped steel section frequently used to support masonry over a window or door opening.

ANGLE OF INCIDENCE
The angle that the sun's rays make with a line perpendicular to a surface. The angle of incidence determines the percentage of direct sunshine intercepted by a surface.

ANHYDROUS LIME
Quicklime.

ANNUAL
A plant with a life span of one year's duration.

ANNUAL GROWTH RING
The ring seen on the transverse section of a piece of wood indicating yearly growth.  Also referred to as grain.  See also year ring.

APARTMENT
A room or suite of rooms used as living quarters.  A dwelling unit of a multi-family house.  See dwelling, multiple.

APARTMENT BUILDING
A type of multiple dwelling comprising three or more dwelling units with shared entrances, and other essential facilities and services, and with shared exit facilities above the first storey.

APRON
A plain or moulded finish piece below the sill of a window, installed to cover the rough edge of the wall finish.  Also the extension of the concrete floor of a garage or other structure, beyond the face of the building.

AQUIFER
An underground formation of sands, gravel, or fractured or porous rock, which is saturated with water, and which supplies water for wells and springs.

ARCADE
A row of arches supported by columns, which may be either attached to a building or free standing.

ARCH
A mechanical arrangement of building materials which are put together , generally along a curved line, in such a way that, supported by piers, abutments, or walls, they carry weight and resist pressure.

ARCH BRICK
A brick having a wedge shape, also one with a curved face suitable for wells and other circular work.

ARCHINTRAVE
Mouldings around openings and certain other locations to conceal joints or for decorative purposes.

AREA
of building:  The maximum projected horizontal area of the building at or above grade within the outside perimeter of the exterior walls, or within the the outside perimeter of exterior walls and the centre line of fire walls.
floor:  The space on any storey of a building building between exterior walls and required firewalls, including the space occupied by interior walls and partitions, but not including exits and vertical spaces that pierce the storey.
gross: In reference to a structural unit, shall mean the total area within the outer periphery of any section perpendicular to the stress to be resisted.
net:  In reference to a structural unit, shall mean the minimum effective load-bearing area of the material composing the unit, included in any section perpendicular to the direction of the stress to be resisted.
net room:  The floor area of a room measured from finished wall to finished wall.

AREAWAY
An open sub-surface space, adjacent to a building, used to admit light or air, or as a means of access to an area or floor level below grade.

ARTIFICIAL STONE
A special concrete unit, sometimes artificially coloured, intended to resemble natural stone, made by mixing chippings and dust of natural stone with Portland cement and water.  This mixture is placed in moulds and cured before use.

ASBESTOS CEMENT
A fire-resisting weatherproof building material made from Portland cement and asbestos.  It is manufactured in various forms such as plain sheets, corrugated sheets, shingles, pipes, etc.

ASHLAR
See stonework, kinds of.

ASPHALT (BITUMINOUS)
A dark substance which is insoluble in water and used extensively in building for waterproofing, roof coverings, in the manufacture of shingles and floor tiles, and in paints.  See also paving.

ASTRAGAL
A small plain or ornamental moulding.

AT GRADE
A term applied to the part of a structure or site feature which is located at the same elevation as the adjacent finished ground level.

ATRIUM
An enclosed interior court, of one or more levels high, on to which other rooms may open.

ATTIC OR ROOF SPACE
The space between the top floor ceiling and roof, and between a dwarf partition and sloping roof.

ATTIC VENTILATORS
The screened openings in houses provided to ventilate an attic space. They are located in the soffit area as  inlet ventilators and in the gable end or along the ridge as outlet ventilators. They can also consist of power-driven fans used as an exhaust system. See also LOUVER.

AWNING
A shading device on a metal frame mounted on the outside of the window.

AWNING WINDOW
A top hinged sash.

AZIMUTH
The angular distance between true south and the point on the horizon directly below the sun.

-B-

BACK-DRAFTING (FLOW REVERSAL)
The reverse flow of chimney gases into the building through the barometric damper, draft hood, or burner unit. This can be caused by chimney blockage or it can occur when the pressure differential is too high for the chimney to draw.

BACKFILL
The material used to re-fill an excavation around the outside of a foundation wall or pipe trench.

BALLOON FRAMING
A method of wood-frame construction in which the studs extend in one piece from the foundation sill to the
top plate supporting the roof.

BASEBOARD
A molded board placed against the wall around a room next to the floor to conceal the joint between the
floor and wall finish.

BASE COURSE
In masonry, the first or bottom course of brick or other masonry units.

BASEMENT
The lower storey of a building, below or partly below ground level.

BATTEN
A narrow strip of wood used to cover joints between boards or panels.

BATTER BOARD
The boards set at right angles to each other at each corner of an excavation, used to indicate the level and alignment of the foundation wall.

BAY WINDOW
A window which projects outside the main line of a building.

BEAM
A horizontal structural member supporting a vertical load, usually made of wood, steel or concrete, supported at two or more points but not
throughout its length, which typically runs down the centre of the longest axis of a house. 

BEAM POCKET
A notch formed at the top of a wall to receive and support the end of a beam.

BEARING
The part of a joist, rafter, truss or beam which actually rests on its support and the area of the support on
which it rests.

BEARING PARTITION
A partition that supports any vertical load in addition to its own weight.

BEARING WALL
A wall that supports any vertical load in addition to its own weight.

BERM
A man-made mound or small hill of earth.

BEVEL
The sloping surface formed when two surfaces meet at an angle which is not a right angle.

BEVEL SIDING
Any boards tapered to a thin edge and used as exterior wall covering.

BLIND-NAILING
The practice of nailing so that the nail heads are not visible on the face of the work - usually at the tongue of
matched boards.

BLOCKING
The short pieces nailed between major framing members to act as fire-stops or provide a nailing surface.

BOARD
Any lumber less than nominally 51 mm (2 inches) thick and wider than 100 mm (4 inches).

BOTTOM PLATE
The lower horizontal member of a wood-frame wall nailed to the bottom of the wall studs and to the floor
framing members.

BRACE
A diagonal framing member fastened to major horizontal and vertical members to provide a triangle and
thereby stiffen the framing.

BREAKING JOINTS
The manner of laying masonry units so as to avoid vertical joints in adjacent courses from lining up. Also the distribution of joints in boards, flooring, lath and panels so no two adjacent end-joints are directly in line.

BRICK MOULDING
A standard milled wood trim piece to cover the gap between the window frame and masonry.

BRICK VENEER
A facing of brick tied to a wood frame or masonry wall, serving as a wall covering only and carrying no
structural loads.

BTU
An abbreviation for British Thermal Unit; the heat required to increase the temperature of one pound of
water one degree Fahrenheit.

BUILT-UP ROOF
A roof covering composed of three or more layers of roofing felt or fibreglass saturated with coal, tar or asphalt. The top is finished with crushed stone, gravel or a cap sheet. Generally used on flat or low-pitched
roofs.

BUTT-JOINT
Any joint made by fastening two members together without overlapping.

-C-

CANT (STRIP)
A triangular-shaped piece of lumber used around the perimeter of flat roofs or at the junction of a flat deck and a wall to prevent cracking of the roofing which is applied over it.

CASEMENT WINDOW
A frame which contains a sash hinged at the side to open in or out. In-swinging are French in origin while out-swinging are from England.

CASING
A form of moulded trim used around window and door openings.

CAULKING
The practice of sealing a joint in a building.

CENTRE-HUNG SASH
A sash that pivots on pins in the middle of the sash stiles and sides of the window frame to allow access for
cleaning from the inside

CERTIFYING AGENCY
An accredited organization which provides standards, certification, testing and inspection on the performance of a product under various conditions before it is available for public use.  The tested product will bear the testing agency's certification mark.  The mark indicates that representative samples have been tested and meet the requirements of accepted standards for desirable levels of safety and/or performance, and that the manufacturer is committed to an ongoing program of production review by the testing agency.  The major certifying agencies and laboratories in Canada are Canadian Standards Association (CSA), Underwriters Laboratories of Canada (ULC), Canadian Gas Association (CGA) and Warnock Hersey Inc. (WH).

CHECKING
The fissures that appear with age in many exterior paint coatings, at first superficial, but which in time may penetrate entirely through the coating. They may also appear in siding or lumber.

CHIMNEY FLUE
A passage housed in a chimney through which smoke and gases are carried from a fuel burning appliance, fireplace or incinerator to the exterior.

CLERESTORY
An outside wall of a room or building, carried above an adjoining roof and pierced with windows.

COLLAR BRACE (COLLAR TIE)
A horizontal piece of lumber used to provide intermediate support for opposite roof rafters, usually located in the middle third of the rafters. Also called collar beam or collar tie.

COLUMN
A vertical free-standing load-carrying member.

COMBINATION DOORS OR WINDOWS
The combination doors or windows used over regular openings. They provide winter insulation and summer protection and often have self-storing or removable glass and screen inserts. This eliminates the need for handling a different unit each season.

COMBUSTIBLE AND NON-COMBUSTIBLE MATERIALS
Within the range of temperatures that may occur in a building either normally or under fire conditions, materials are classified as combustible or non-combustible. The term non-combustible is generally applied to materials of construction which conform to National Standard of Canada. CAN4S114-78, Standard Method of Test for Determination of Non-Combustibility in Building Materials. Scarborough, Ontario: Underwriters Laboratories of Canada, 1980.

COMBUSTION AIR
The air required to provide adequate oxygen for fuel burning appliances in the building. The term 'combustion air' is often used to refer to the total air requirements of a fuel burning appliance including both air to support the combustion process and air to provide chimney draft (dilution air).

COMMON RAFTER
One of a series of rafters extending from the top of an exterior wall to the ridge of a roof.

CONDENSATION
The transformation of the vapour content of the air into water on cold surfaces. The beads or drops of water (and frequently frost in extremely cold weather) that accumulate on the inside of the exterior covering of a building when warm, moisture-laden air from the interior reaches a point where the temperature no longer permits the air to sustain the moisture it holds.

CONDUCTION
The transfer or travel of heat through a body by molecular action.

CONDUIT (ELECTRICAL)
A pipe, usually metal, in which wire is installed.

CONSTRUCTION DRY-WALL
A type of construction in which the interior wall finish is applied in a dry condition, generally in the form of sheet materials or wood paneling, as opposed to plaster.

CONSTRUCTION, WOOD FRAME
A type of construction in which the structural parts are wood or depend upon a wood frame for support. In codes, if masonry veneer is applied to the exterior walls, the classification of this type of construction is usually unchanged.

CONTROL JOINT
A straight line joint placed in concrete to form a plane of weakness to prevent random cracks from forming due to shrinkage or stress.  If stress or movement is sufficient, the cracks will occur at the control joints and thus be inconspicuous.  This can be a saw cut (a groove formed with a hand-finishing tool) or a pre-moulded strip.  On a concrete slab, control joints permit horizontal movement.  The depth of the joints should be one-quarter of the slab's thickness.

CONVECTION
The transfer of heat by the movement of a fluid (water, air, etc.).

CONVECTIVE LOOPS
A type of air movement occurring in and around the building envelope caused by gaps in the insulation, weather barrier or air barrier. For example, in an uninsulated wall cavity, air removes heat from the warm interior wall, then circulates to the colder exterior wall where it loses the heat.

CORBEL OUT
The practice of building out one or more courses of brick or stone from the face of a wall, often used to form a support for timbers.

CORNER BOARDS
A built-up wood member installed vertically on the external corners of a house or other frame structure against which the ends of the siding are butted.

CORNER BRACES
The diagonal braces at the corners of a frame structure used to stiffen and strengthen the wall.

CORNICE
A horizontal projection at the top of a wall or column; often referring to the overhang of a pitched roof at the eave line, usually consisting of a facia board, a soffit or a closed cornice and appropriate mouldings.

COUNTER-FLASHING
A flashing usually used on chimneys at the roofline to cover shingle flashing and to prevent moisture entry.

COURSE
A continuous horizontal layer of bricks or masonry units in buildings; the term is also applicable to shingles.

COVE MOULDING
A molding with a concave face used as a trim or to finish interior corners.

CRAWL SPACE
A shallow space below the living quarters of a house with no basement area, normally enclosed by the foundation
wall.

CROSS-BRIDGING
The diagonal bracing between adjacent floor joists, placed near the centre of the joist span to prevent joists
from twisting.

CURING (OF CONCRETE)
The maintenance of proper temperature and moisture conditions to promote the continued chemical reaction which takes place between the water and the cement.

CUT-IN BRACE
A nominal 51 mm (2 inch) thick member, usually a 38 mm by 89 mm (2 x 4) cut in between each stud diagonally.

-D-

DAMP-PROOF COURSE
A damp-proof material placed just above the ground level in a brick or stone wall to prevent ground moisture from seeping up through the structure.

DAMP-PROOFING
The process of coating the outside of a foundation wall with a special preparation to resist passage of moisture through the wall, or materials used to resist the passage of moisture through concrete floor slabs and from masonry to wood.  The purpose of damp-proofing is to prevent the capillary movement of moisture into the wall system and to the interior of the foundation; used where water is not exerting pressure on the outside surface of walls.  See also water-proofing.

DEAD AIR SPACE (STILL AIR SPACE)
A confined space of air. A dead air space tends to reduce both conduction and convection of heat. This fact is utilized in virtually all insulation materials and systems, such as double glazing, fibreglass batts, rigid foam panels and loose fill insulations, such as vermiculite and cellulose.

DECAY
The disintegration of wood or other substance through the action of fungi.

DEGREE DAY (HEATING)
The difference between a base temperature and the average temperature of a day. The base is usually 18° (64°).

DEHUMIDISTAT
An electronic control and sensing device used to regulate mechanical ventilation according to relative humidity.  When the relative humidity surpasses the preset limit, the dehumidistat activates the ventilation system to exhaust house air and bring in drier outdoor air.

DENSITY
The mass of a substance in a unit volume. When expressed in the metric system, it is numerically equal to the specific gravity of the same substance.

DEWPOINT
The temperature at which a vapour begins to deposit as a liquid. Applies especially to water in the atmosphere.  The temperature at which a given volume of air is saturated with water vapour (i.e., 100% relative humidity.)  If the saturated air is in contact with a surface below this temperature, condensation will form on the surface.

DIFFUSE RADIATION
Radiation that has travelled an indirect path from the sun because it has been scattered by particles in the atmosphere, such as air molecules, dust and water vapour.

DIFFUSION
The movement of water vapour between 2 areas caused by a difference in vapour pressure, independent of air movement. The rate of diffusion is determined by 1) the difference in vapour pressure, 2) the distance the vapour must travel, and 3) the permeability of the material to water vapour. Hence the selection of materials of low permeability for use as vapour retarders in buildings.

DILUTION AIR
The air required by some combustion heating systems in order to isolate the furnace from outside pressure fluctuations and to maintain an effectively constant chimney draft.

DIRECT GAIN
Solar energy collected (as heat) in a building without special solar collection devices, such as through windows or by being absorbed by a roof or exterior walls.

DIRECT NAILING
The practice of nailing perpendicular to the initial surface or to the junction of the pieces joined. Also termed face nailing. Fastening a member by driving nails through it at right angles to its exposed surface.

DOOR JAMB
The surrounding case into and out of which a door closes and opens. It consists of two upright pieces, called side jambs, and a horizontal head jamb.

DORMER
An opening in a sloping roof, the framing of which projects out to form a vertical wall suitable for windows or other openings.  A small gable in a pitched roof, usually bearing a window or windows on its front vertical face.

DOUBLE-HUNG WINDOW
Window with two vertically moving sashes, each closing a different part of the window.

DOUBLE GLAZING
Two panes of glass in a door or window, with an air space between the panes. They may be sealed hermetically as a single unit or each pane may be installed separately in the door or window sash.

DOWNSPOUT
A pipe, usually of metal or plastic, for carrying rainwater from roof gutters.

DRESSED AND MATCHED (TONGUE AND GROOVE)
A board or plank machined in such a manner that there is a groove on one edge and a corresponding tongue on the other.

DRIP
Continuous recess cut under a sill or protection, to throw off water and prevent it from running down the face of the wall or any other vertical surface.

DRIP CAP
A moulding placed on the exterior top side of a door or window frame to cause water to drip beyond the outside of the frame or at the bottom of a wall of siding (drip mould).

DRUM WALL
A type of wall using stacked 55 gallon drums for heat storage.

DRY ROT
A fungus that decays wood in the presence of moisture and warm conditions and in the absence of light.  A fungus that particularly attacks soft wood.  Most often found in damp or unventilated conditions, and is later able to spread to dry wood, owing to the development of special water-conducting organisms.  The fungus breaks down the cellulose of the wood and the timber becomes brittle.  Often referred to as wet rot, soft rot or wood rot.  The fungus requires moisture to survive.

DRYWALL FINISH
The interior wall and ceiling finish other than plaster - e.g. gypsum board, plywood, fiberboard panels, etc.

DUCTS
The round or rectangular metal pipes in a house used for distributing warm air from the heating plant to rooms, or air from a conditioning device or as cold air returns.

DWARF WALL
A framed wall of less than normal full height. (Also called a knee-wall).

-E-

EAVE
The lower part of a roof which projects beyond the face of the walls.

EAVE SOFFIT
The under surface of the eave.

EAVE TROUGH
A trough fixed to an eave to collect and carry away the run-off from the roof. Also called a gutter.

END MATCHED
A board having tongued and grooved ends.

EQUIVALENT LEAKAGE AREA (ELA)
The total area of all the unintentional openings in a building's envelope, generally expressed in square
centimetres.

EXFILTRATION
The uncontrolled leakage of air out of a building.

EXPANDED METAL
A metal network formed by stamping or cutting sheet-metal and stretching it to form open meshes. It is used as reinforcing in concrete construction and as lath for plastering and stucco.

-F-

FACE NAILING
The practice of fastening a member by driving nails through it at right angles to its exposed surface.

FAN
An air moving device comprising a wheel or blade, and housing or office plate.

FASCIA BOARD
A finish member around the face of eaves and roof projections.

FENESTRATION
The area and arrangement of windows.

FIRE-RESISTANCE RATING
The time in hours or fraction thereof that a material or assembly of materials will withstand the passage of flame and the transmission of heat when exposed to fire under specified conditions of test and performance criteria.

FIRE-RESISTIVE
A designation applied, in the absence of a specific ruling by the authority having jurisdiction, to materials for construction not combustible in the temperatures of ordinary fires; materials that will withstand such fires without serious impairment of their usefulness for at least 1 hour.

FIRE-RETARDANT CHEMICAL
A chemical or preparation of chemicals used to reduce flammability or to retard spread of flame.

FIRE STOP
A solid, tight closure of a concealed space, placed to prevent the spread of fire and smoke through such a space. In a frame wall, this will usually consist of 38 mm by 89 mm (2 x 4) cross blocking between studs.

FISHPLATE
A wood or plywood piece used to fasten the ends of two members together at a butt joint with nails or bolts. Sometimes used at the junction of opposite rafters near the ridge line.

FLASHING
A material, such as sheet metal, used in roof and wall construction to shed water.

FLOORING
A material used in the construction of floors. The surface material is known as finish flooring while the base material is called sub-flooring.

FLUE
The space or passage in a chimney through which smoke, gas, or fumes ascend. Each passage is called a flue, which together with any others and the surrounding masonry make up the chimney.

FLUE LINING
A fire clay or terra-cotta pipe, round or square, usually made in all ordinary flue sizes and in 610 mm (24 inches) lengths, used for the inner lining of chimneys with the brick or masonry work around the outside.  Flue lining in chimneys runs from about 305 mm (12 inches) below the flue connection to the top of the chimney.

FLY RAFTERS
The end rafters of the gable overhang supported by roof sheathing and lookouts.

FOOT CANDLE
Unit of measure of the intensity of light, defined by the light at a distance of one foot from an International Candle.

FOOTING
A masonry section usually concrete, in a rectangular form wider than the bottom of the foundation wall or pier it supports.

FOUNDATION
The supporting portion of a structure below the first-floor construction, or below grade, including the footings, which transfers the weight of, and loads of, the structure to the ground.

FRAMING
The skeleton of the building. The rough timber work of a house, including the flooring, roofing, partitioning and beams.

FRAMING, BALLOON
A system of framing a building in which all vertical structural elements of the bearing walls and partitions consist of single pieces extending from the top of the foundation sill plate to the roof plate and to which all floor joists are fastened.

FRAMING, PLATFORM
A system of framing a building in which floor joists of each storey rest on the top plates of the storey below or on the foundation sill for the first storey and the bearing walls and partitions rest on the subfloor of each storey

FRIEZE
A horizontal member used in house construction to connect the top of the siding with the soffit of the cornice.

FROST LINE
The depth of frost penetration in soil. This depth varies in different parts of the country. Footings should be placed below this depth to prevent movement.

FUNGI WOOD
The microscopic plants that live in damp wood and cause mould, stain, and decay.

FUNGICIDE
A chemical that is poisonous to fungi.

FURRING
The strips of wood or metal applied to a wall or other surface to even it and normally to serve as a fastening base for finish material.

-G-

GABLE
The upper triangular-shaped portion of the end wall of a house above the eave line of a double sloped roof.

GABLE END
The entire end wall of a house having a gable roof.

GAUGE
A standard for measuring e.g. diameter of nails or wire and thickness of metal sheets, etc.

GEOTHERMAL ENERGY
Heat energy contained in large underground reservoirs of steam and hot water, produced by molten material from the earth's interior.

GIRDER
A large beam supporting floor joists at the same level as the sills. A larger or principal beam used to support concentrated loads at isolated points along its length.

GIRT
A large horizontal beam supporting the ends of upper storey floor joists between posts.

GLASS
An elastic transparent material composed of silica (sand), soda (sodium carbonate) and lime (calcium carbonate) with small quantities of alumina, boric or magnesia oxides.

GLAZIER'S POINT
A thin metal triangle with one point pounded into the frame to hold the glass, putty is then applied to seal the glass.

GLOSS (PAINT OR ENAMEL)
A paint or enamel that contains a relatively low proportion of pigment and dries to a sheen or luster.

GRADE
The surface slope. The level of the ground surface around the foundation wall. To modify the ground surface by cut and fill.

GRADE LINE
A pre-determined line indicating the proposed elevation of the ground surface around a building.

GRADE (LUMBER)
A classification of lumber depending upon its suitability for different uses.

GRAIN
The direction, size, arrangement, appearance, or quality of the fibres in wood.

GUSSET
A flat wood, plywood, or similar type member used to provide a connection at intersection of wood members. Most commonly used at joints of wood trusses. They are fastened by nails, screws, bolts, or adhesives.

GUTTER OR EAVE TROUGH
A shallow channel or conduit of metal, plastic or wood set below and along the eaves of a house to catch and carry off rainwater from the roof.

GYPSUM PLASTER
The combination of gypsum with sand and water for making base-coat plaster.

-H-

HEADER (FRAMING)
A wood member at right angles to a series of joists or rafters at which the joists or rafters terminate. When used at openings in the floor or roof system the header supports the joist or rafters and acts as a beam.

HEARTH
The inner or outer floor of a fireplace, usually made of brick, tile, or stone.

HEAT EXCHANGER
A device specifically designed to transfer heat between two physically separated fluids, such as air.

HEAT GAIN
An increase in the amount of heat contained in a space, resulting from direct solar radiation and the heat given off by people, lights, equipment, machinery and other sources.

HEATING
Air-Conditioning : The process of bringing air to a required state of temperature and humidity, and removing dust, pollen and other foreign matter.
Baseboard Heater : A radiator shaped like a decorative baseboard having openings at the top and bottom through which air circulates.
Central Heating : A heating system in which a number of rooms or spaces are heated from a central source.
Combination : Provides domestic hot water as well as heating the house, often using a fan coil to distribute heat through air ducts.
Convector : A heating device in which the air enters through an opening near the floor, is heated as it passes through the heating element and enters the room through an upper opening.
Hot Water Heating : The circulation of hot water through a system of pipes and radiators either by gravity or a circulating pump.
Panel Heating : Coils or ducts installed in wall, floor or ceiling panels to provide a large surface supply of low intensity heat.
Radiant Heating : A heating system in which only the heat radiated from panels is effective in providing the heating requirements.
Warm Air Heating : A warm air heating plant consisting of a heating unit (fuel-burning furnace) enclosed in a casing, from which the heated air is distributed to various rooms of the building through ducts.

HEAT LOSS
A decrease in the amount of heat contained in a space, resulting from heat flow through walls, windows, roof and other building envelope components.

HEAT PUMP
A heating device which extracts usable heat from a medium like air or water by raising (pumping) its temperature. In its reverse it can be used for cooling.

HEAT SINK
A body which is capable of accepting and storing heat, and therefore may be used as a heat source.

HERMETICAL SEALING
The practice of making a material impervious to air and other fluids by fusion.

HIP
The sloping ridge of a roof formed by two intersecting roof slopes.

HIP-RAFTER
The rafter which forms the hip of a roof.

HIP ROOF
A roof that rises by inclined planes from all four sides of a building.

HOPPER LIGHT
Inward opening sash hinged at the bottom.

HUMIDIFIER
A device designed to increase the humidity within a room or a house by means of the discharge of water vapour. It may consist of an individual room-size unit or a larger unit attached to the heating plant to condition the entire house.

HUMIDITY
The amount of water vapour in the air.

-I-

I-BEAM
A steel beam with a cross section resembling the letter I.  It is used for long spans as basement beams or over wide wall openings, such as a double garage door,when wall and roof loads are imposed on the opening.

IMPERMEABLE
Not permitting water vapour or other fluid to pass through.

INFILTRATION
The uncontrolled leakage of air into a building.

INSOLATION INCIDENT SOLAR RADIATION
The total amount of solar radiation (direct, diffused and reflected) striking a surface exposed to the sky.  This incident solar radiation is measured in Langleys per minute, or BTU's per square foot per hour or per day.

INSULATION
Any material high in resistance to heat transmission that, when placed in the walls, ceiling, or floors of a structure, will reduce the rate of heat flow.
Blown : Low density, loose insulation material which is mechanically installed.
Electrical : Non-conducting covering applied to wire or equipment to prevent short circuiting.
Friction Fit : Batt insulation which is held secure within framing members by friction.
Rigid : Dense insulation material that is structurally rigid. Also called board insulation.
Spray foam (foam-in-place) : Expanding foam, usually mixed on-site, and sprayed into the open wall cavity of an unfinished wall, or or injected through holes drilled in the sheathing or drywall, into the wall cavity of a finished wall.

INTERIOR FINISH
The covering used on interior walls and ceilings.

INTERIOR TRIM
All the interior woodwork designed to conceal joints.

ISOLATED GAIN SYSTEM
A system where solar collection and heat storage are isolated from the living space.

-J-

JACK RAFTER
A rafter that spans the distance from the wall-plate to a hip, or from a valley rafter to the roof ridge.

JAMB
The side post or lining of a doorway, window or other opening.

JOIST
One of a series of horizontal wood members, usually 50 mm (2 inches) nominal thickness, used for support.  (eg. floor joist, ceiling joist or roof joist.) A parallel beam used to support floor and ceiling loads, and supported in turn by larger beams, girders, or bearing walls.

JOIST HANGER
A steel section shaped like a stirrup, bent so it can be fastened to a beam to provide end support for joists, headers, etc.

-K-

KNEE WALL
Partitions of varying length used to support roof rafters when the span is so great that additional support is required to stiffen them.

-L-

LANDING
A platform between flights of stairs or at the termination of a flight of stairs.

LATH
A building material of wood, metal, gypsum or insulating board that is fastened to the frame of a building to act as a plaster base.

LATITUDE
The angular distance north (+) or south (-) of the equator, measured in degrees of an arc.

LATTICE
A framework of crossed wood or metal strips.

LEDGER STRIP
A strip of lumber fastened along the bottom of the side of a beam on which joists rest.

LEEWARD
The side (or sides) of a house which face away from the prevailing winds.

LET-IN BRACE
A nominal 25 mm (1 inch) thick board applied into notched studs diagonally.

LIGHT (LITE)
A space in a window sash for a single pane of glass. Also, a pane of glass.

LINEAR FOOT
A length of 305 mm (12 inches) independent of area or volume.

LINTEL
A horizontal structural member that supports the load over an opening such as a door or window.

LIVE LOAD
The weight due to occupancy of a building.

LOOKOUT RAFTERS
The short wood members cantilevered over a wall to support an overhanging portion of a roof.

LOUVER
An opening with a series of horizontal slats so arranged as to permit ventilation but to exclude rain, sunlight, or vision. See also ATTIC VENTILATORS.

LUMBER
Any wood which has been sawed and planed only.

LUMBER, BOARDS
Sawn lumber less than 51 mm (2 inches) thick and 100 mm (4 inches) or more wide.

LUMBER, DIMENSION
All yard lumber from 51 mm (2 inches) to, but not including, 127 mm (5 inches) thick and 51 mm (2 inches) or more wide. Includes joists, rafters, studs, planks, and small timbers.

LUMBER, DRESSED SIZE
The dimension of lumber after shrinking from green dimension and after machining to size or pattern.

LUMBER, MATCHED
Any lumber that is dressed and shaped on one edge in a grooved pattern and on the other in a tongued pattern.

LUMBER, SHIPLAP
Any lumber that is edge-dressed to make a close rabbeted or lapped joint.

LUMBER, TIMBERS
Any yard lumber 127 mm (5 inches) or more in least dimension. Includes beams, stringers, posts, caps, sills, girders, and purling.

LUMBER, YARD
All lumber of those grades, sizes and patterns which are generally intended for ordinary construction, such as framework and rough coverage of houses.

LUMEN
A unit of measure for the flow of light, equal to the amount of flow through a unit solid angle from a uniform point source of one International candle.

-M-

MANSARD ROOF
A double-pitched roof with the lower section containing dormers.

MANTEL
The shelf above a fireplace. Also used in referring to the decorative trim around a fireplace opening.

MASONRY
The combination of stone, brick, concrete, hollow-tile, concrete-block, gypsum block or other similar building units or materials, bonded together with mortar to form a wall, pier, buttress or similar mass.

MASTIC
A pasty material used as a cement (as for setting tile) or a protective coating (as for thermal insulation, sealing or waterproofing).

MESH
A reinforcement for concrete, plaster or stucco, usually expanded metal or woven wire.

METAL LATH
A base for plaster or stucco, usually expanded metal or woven wire.

MIL
One-thousandth of an inch, or 0.0254 millimetres.

MILLWORK
All building materials made of finished wood and manufactured in millwork plants and planing mills are included under the term 'millwork'. It includes such items as inside and outside doors, window and door frames, blinds, porchwork, mantels, panelwork, stairways, mouldings and interior trim. It normally does not include flooring, ceiling or siding.

MINERAL WOOL
A material used for insulating buildings, produced by sending a blast of steam through molten slag or rock; common types now in use include rock wool, glass wool and slag wool.

MITER JOINT
The joint of two pieces at an angle that bisects the joining angle. For example, the miter joint at the side and head casing at a door opening is made at a 45° angle.

MOISTURE CONTENT OF WOOD
The weight of the water contained in wood, usually expressed as a percentage of the weight of the oven-dry wood.

MOULDING
A piece of shaped wood used to decorate or conceal a joint.

MORTAR
A substance produced from prescribed proportions of cementing agents, aggregates and water which gradually sets hard after mixing.

MORTAR BED
The layer of mortar on which any structural member, masonry unit or tile is bedded.

MORTISE
A slot cut into a board, plank, or timber, usually edgewise, to receive a tenon or another board, plank or timber to form a joint or to receive a lock, hinge, etc.

MUDSILL
Any timber placed directly on the ground as a foundation for a structure.

MULLION
Vertical member between window units.

MUNTIN
A secondary framing member (horizontal, vertical or slanted) to hold the window panes in the sash. This term is often confused with Mullion.

-N-

NOMINAL SIZE
The rough size of a member before planing. The ordinary commercial size by which timber or lumber is known and sold on the market, but it may differ from the actual size.

NON-BEARING PARTITION
A wall which separates space into rooms, but supports no vertical load except its own weight.

NON-BEARING WALL
A wall supporting no load other than its own weight.

NOTCH
A crosswise rabbet at the end of a board.

-O-

O.C., ON CENTRE
The measurement of spacing for structural members like studs, rafters and joists in a building, from the centre of one member to the centre of the next.

OUTRIGGER
An extension of a rafter beyond the wall line. Usually a smaller member nailed to a larger rafter to form a cornice or roof overhang.

-P-

PAINT
A combination of pigments with suitable thinners or oils to provide decorative and protective coatings.

PANE
A sheet of glass for glazing a window. After installation, the pane is referred to as a 'light' (lite) or 'window light'.

PANEL
A large board or sheet of lumber, plywood, or other material. A thin board with all its edges inserted in a groove of a surrounding frame of thick material. A portion of a flat surface recessed or sunk below the surrounding area, distinctly set off by moulding or some other decorative device. Also, a section of floor, wall, ceiling or roof, usually prefabricated and of large size, handled as a single unit in the operations of
assembly and erection.

PAPER, BUILDING
A breather-type sheathing paper usually applied underneath or behind exterior finish material in wood frame construction. A general term for papers, felts and similar sheet materials used in buildings without reference to their properties or uses.

PAPER, SHEATHING
A breather type tar or asphalt used under extension wall cladding as protection against the passage of air or water. A building material, generally paper or felt, used in wall and roof construction as a protection against the passage of air and sometimes moisture.

PARAPET WALL
The part of an exterior, party or firewall extending above the roof line; a wall which serves as a guard at the edge of a balcony or roof.

PARGING
A coat of plaster or cement mortar applied to masonry or concrete walls.

PARTITION
A wall that subdivides spaces within any storey of a building.

PERM
An imperial unit measure of water vapour movement through a material (grains per square foot per hour per inch of mercury difference in vapour pressure.)

PERMEABILITY
A measure of the ease with which water vapour passes through a unit thickness of a material.

PERMEANCE
Water vapour permeance is the rate of water vapour diffusion through a sheet of any thickness of material (or assembly between parallel surfaces). It is the ratio of water vapour flow to the differences of the vapour pressures on the opposite surfaces. Permeance is measured in perms (m².C/W).

PIER
A column of masonry, usually rectangular in horizontal cross section, used to support other structural members.

PITCH
The incline slope of a roof or the ratio of the total rise to the total width of a house, i.e. a 2.4 m (8 feet) rise and 7.3 m (24 feet) width is a one-third pitch roof.

PITCHED ROOF
A roof which has one or more surfaces sloping at angles greater than necessary for drainage.

PLAIN CONCRETE
Any unreinforced concrete.

PLAN
A drawing representing the horizontal arrangement of a site or building to a given scale.

PLATE
The sill plate : a horizontal member anchored to a masonry wall.
Sole plate : bottom horizontal member of a frame wall.
Top plate : top horizontal member of a frame wall supporting ceiling joists, rafters or other members.

PLATFORM FRAME
A house frame in which the floor joists of one storey rest on the top plate of the wall below.

PLUMB
The state of being exactly perpendicular, vertical.

PLY
A term to denote the number of thicknesses or layers of roofing felt, veneer in plywood, or layers in built-up materials, in any finished piece of such material.

PLYWOOD
A piece of wood made of three or more layers of veneer joined with glue, and usually laid with the grain of adjoining plies at right angles. Almost always an odd number of plies are used to provide balanced construction.

POSITIVE PRESSURE
A pressure above atmospheric. In residential construction this refers to pressure inside the house envelope that is greater than the outside pressure; a positive pressure difference will encourage exfiltration.

POST
The vertical wall members at the corners and wall intersections.

PRESERVATIVE
Any substance that, for a reasonable length of time, will prevent the action of wood destroying fungi, borers of various kinds, and similar destructive agents when the wood has been properly coated or impregnated
with it.

PRESSURE DIFFERENCE
The difference in pressure of the volume of air enclosed by the house envelope and the air surrounding the envelope.

PRIMER
The first coat of paint in a paint job that consists of two or more coats; also the paint used for such a
first coat.

PURLIN
The members at right angles to rafters serving to break up the roof board span.

PUTTY
A type of cement usually made of whiting and boiled linseed oil, beaten or kneaded to the consistency of dough, and used in sealing glass in sash, filling small holes and crevices in wood, and for similar purposes.

-Q-

QUARTER ROUND
A moulding that has the cross section of a quarter circle.

-R-

RADIANT HEATING
A method of heating, usually consisting of a forced hot water system with pipes placed in the floor, wall or ceiling; or with electrically heated cables or panels.

RADIANT HEAT TRANSFER
The transfer of heat energy from a location of higher temperature to a location of lower temperature by means of electromagnetic radiation.

RADIATION, ULTRA-VIOLET (UV)
Electromagnetic radiation, usually from the sun, that consists of wavelengths shorter than the violet end of the visible spectrum (less than 0.15 microns). Five percent of the sun's radiation is emitted in the ultra-violet band.

RAFTER
A structural member of a roof designed to support roof loads. The rafters of a flat roof are sometimes called roof joists.

RAFTER, HIP
A rafter that forms the intersection of an external roof angle.

RAFTER, VALLEY
A rafter that forms the intersection of an internal roof angle. The valley rafter is normally made of double 51 mm (2 inch) thick members.

RAKE
The trim members that run parallel to the roof slope and form the finish between the wall and a gable roof extension.

RECEPTACLE (ELECTRIC)
A mounted electrical outlet.

RECOVERED ENERGY
Energy utilized which would otherwise be wasted

RECYCLE
Recovery and reuse of materials and resources.

REINFORCING
The practice of placing steel rods or metal fabric in concrete slabs, beams or columns to increase their strength.

RELATIVE HUMIDITY
The ratio of actual pressure of existing water vapour to maximum possible pressure of water vapour in the atmosphere at the same temperature, expressed as a percentage. For example, air containing one half the amount of moisture it is capable of holding has a relative humidity of 50%.

RESISTANCE VALUE (RSI or R-VALUE)
Thermal resistance value. A metric measurement of the ability of a material to resist heat transfer.

RIBBON (GIRT)
A 25 mm (1 inch) by 102 mm (4 inch) let into the studs horizontally to support ceiling or second-floor joists.  Replaces the girt in balloon frame.

RIDGE
The horizontal line at the junction of the top edges of two sloping roof surfaces.

RIDGE BEAM
A horizontal structural member usually 51mm (2 inches) thick, supporting the upper ends of rafters.

RIDGE BOARD
The board placed on edge at the ridge of the roof into which the upper ends of the rafters are fastened.

ROCK STORAGE SYSTEM
A solar energy system in which the collected heat is stored in a rock bin for later use. This type of storage can be used in an active, hybrid or even passive system. However, rock storage is primarily used with a system which circulates air as the transfer medium between the collector and storage to the heated space.

ROLL ROOFING
A roofing material, composed of fibre and saturated with asphalt, that is supplied in 914 mm (36 inch) wide rolls with a 10 square metre (100 square feet) of material. Weights are generally 20 to 41 kg (50 to 90 lbs) per roll.

ROOF SHEATHING
The boards or sheet material fastened to the roof rafters on which the shingle or other roof covering is laid.

ROOFERS
The roof boards nailed to rafters or purling.

ROUGH LUMBER
Any lumber that has been sawn but not planed.

RUBBER-EMULSION PAINT
Any paint, the vehicle of which consists of rubber or synthetic rubber dispersed in fine droplets in water.

-S-

SADDLE
The two sloping surfaces meeting in a horizontal ridge, used between the back side of a chimney, or other vertical surface, and a sloping roof. Also called a cricket.

SASH
The framework which holds the glass in a window.

SASH BALANCE
A device, usually operated by a spring or tensioned weatherstripping designed to counterbalance double-hung window sash.

SATURATED FELT
A felt which is impregnated with tar or asphalt.

SECTION
A drawing of a building in the vertical plane.

SEMIGLOSS PAINT OR ENAMEL
A paint or enamel made with a slight insufficiency of non-volatile vehicle so that its coating, when dry, has some luster but is not very glossy.

SENSIBLE HEAT
Heat that results in a temperature change.

SHAKE
A shingle split (not sawn) from a block of wood and used for roofing and siding.

SHEATHING
The material covering the house frame on the exterior.

SHEATHING PAPER
See PAPER, SHEATHING.

SHED ROOF
A sloping roof having its surface in one plane.

SHEET METAL WORK
All components of a house employing sheet metal, such as flashing, gutters and downspouts.

SHEETING
Any material applied in large sheets, usually polyethylene.

SHELLAC
A transparent coating made by dissolving lac, a resinous secretion of the lac bug (an insect that thrives in tropical countries, especially India), in alcohol.

SHINGLES
Any roof covering of asphalt, asbestos, wood, tile, slate or other material cut to stock lengths, widths, and
thicknesses.

SHINGLES, SIDING
The various kinds of shingles, such as wood shingles or shakes and non-wood shingles, that are used over sheathing for exterior side wall covering of a structure.

SHIPLAP
See LUMBER, SHIPLAP.

SHUTTER
The common lightweight louvered or flush wood or non-wood frames in the form of doors located at each side of a window. Some are made to close over the window for protection; others are fastened to the wall as a decorative device.

SIDE LIGHT (MARGIN LIGHT)
A fixed often narrow glass window next to a door opening (or window).

SIDING
The finish covering of the outside wall of a frame building, whether made of horizontal weatherboards, vertical boards with battens, shingles, or other material.

SIDING, BEVEL (LAP SIDING)
The wedge-shaped boards used as horizontal siding in a lapped pattern. This siding varies in butt thickness from 13 mm (1/2 inch) to 19 mm (3/4 inch) and in widths up to 305 mm (12 inches). Normally used over some type of sheathing.

SIDING, DOLLY VARDEN
A beveled wood siding which is rabbeted on the bottom edge.

SIDING DROP
A siding, usually 19 mm (3/4 inch) thick and 152 mm (6 inches) or 203 mm (8 inches) wide with tongued-and-grooved or shiplap edges. Often used as siding without sheathing in secondary buildings.

SILL
The lowest member of the frame of a structure, resting on the foundation and supporting the floor joists or the uprights of the wall. The member forming the lower side of an opening, as a door sill, window sill, etc.

SILL PLATE
A structural member anchored to the top of a foundation wall, upon which the floor joists rest.

SLEEPER
A wood member embedded in concrete, as in a floor, that serves to support and to fasten subfloor or flooring.

SMOKE PIPE
A pipe conveying products of combustion from a solid or liquid fuel-fired appliance to a chimney flue.

SOFFIT
The horizontal or sloping part of the eave.

SOIL COVER (GROUND COVER)
A light covering of plastic film, roll roofing, or similar material used over the soil in crawl spaces of buildings to minimize moisture permeation of the area.

SOIL STACK
A general term for the vertical main of a system of soil, waste or vent piping.

SOLAR ALTITUDE
The angle of the sun above the horizon measured in a vertical plane.

SOLAR ENERGY
Energy in the form of electromagnetic radiation received from the sun.

SOLAR RADIATION
Electromagnetic radiation emitted by the sun.

SOLE OR SOLE PLATE
See PLATE.

SOLID BRIDGING
A solid member placed between adjacent floor joists near the center of the span to prevent joists from twisting.

SPAN
The horizontal distance between supports for beams, joists, rafters, etc.

SPECIFIC HEAT
The number of BTU's required to raise the temperature of one pound of a substance 1° in temperature.

SPLASH BLOCK
A small masonry block laid with the top close to the ground surface to receive roof drainage and divert it away from the building.

SQUARE
A unit of measure (e.g. 9.3 square metres) usually applied to roofing material.

STACK EFFECT
Pressure differential across a building caused by differences in the density of the air due to an indoor-outdoor temperature difference.

STILE
The vertical edge members of a window sash.

STOREY
The part of a building between any floor and the floor or roof next above.

STORM DOOR
An extra outside door for protection against inclement weather.

STORM SASH OR STORM WINDOW
An extra window usually placed on the outside of an existing one as additional protection against cold weather.

STRATIFICATION
The formation of layers in the air where the top layer is warmer than the bottom.

STRING, STRINGER
A timber or other support for cross members in floors or ceilings. In stairs, the support on which the stair treads rest; also stringboard.

STRUT
A structural member which is designed to resist longitudinal compressive stress such as members supporting a ridge beam or rafters; a short column.

STUCCO
An outside plaster made with Portland cement as its base.

STUDS
The vertical framing members between the posts used to support vertical loads and provide nailing surfaces for interior and exterior sheathing.

SUBFLOOR
The boards or sheet material laid on joists under a finished floor.

SURFACED LUMBER
Any lumber that has been planed after sawing.

SUSPENDED CEILING
A ceiling system supported by hanging it from the overhead structural framing.

-T-

TAIL BEAM
A relatively short beam or joist supported in a wall on one end and by a header at the other.

THERMAL BREAK (THERMAL BARRIER)
An element of low heat conductivity placed in such a way as to reduce or prevent the flow of heat.

THERMAL BRIDGE
A low thermal resistance path connecting two surfaces; for example, framing members in insulated frame walls or metal ties in cavity wall and panel construction.

THERMOSTAT
Any device that controls a heating or cooling device by responding to changes in temperature.

THRESHOLD
A strip of wood or metal with beveled edges used over the finish floor and the sill of exterior doors.

TIE BEAM
A beam connecting the base of rafter pairs to prevent outward thrust.

TIMBERS
All wood framing members whose smallest dimension is 127 mm (5 inches).

TOE-NAILING
The practice of nailing at an angle to the first member so as to ensure penetration into a second member.

TONGUE-AND-GROOVE LUMBER
Any lumber, such as boards or planks, machined in such a manner that there is a groove on one edge and a corresponding tongue on the other.

TOP PLATE
The horizontal member nailed to the top of the partition or wall studs in a building.

TRANSOM
A horizontal member separating a door from a window panel above the door, or separating one window above another.

TRIM
The finish materials in a building, such as mouldings, applied around openings (window trim, door trim) or at the floor and ceiling of rooms (baseboard, cornice and other mouldings).

TRIMMER
A beam or joist alongside an opening and into which a header is framed.

TRUSS
Any rafter, ceiling joist and tie assembled in such a way as to span a greater distance than the rafter alone.

-U-

U-VALUE  (Coefficient of heat transfer)
Imperial : The number of BTU's that flow through one square foot of a material in one hour, when there is a 1° difference in temperature between the inside and outside air, under steady state conditions.
Metric : The number of watts that flow through one square metre of a material in one hour, when there is a 1° difference in temperature between the inside and outside air, under steady state conditions.  The U-value is the reciprocal of the resistance or R-value.

-V-

VALLEY
The internal angle formed by the junction of two sloping sides of a roof.

VALLEY RAFTERS
Any rafters which are located at the centre of roof valleys to support the jack rafters.

VAPOUR BARRIER
The material used to retard the movement of water vapour into walls and attics and prevent condensation in them. Applied separately over the warm side of exposed walls.

VAPOUR DIFFUSION
The movement of water vapour between 2 areas caused by a difference in vapour pressure, independent of air movement. The rate of diffusion is determined by 1) the difference in vapour pressure, 2) the distance the vapour must travel, and 3) the permeability of the material to water vapour. Hence the selection of materials of low permeability for use as vapour retarders in buildings.

VAPOUR PRESSURE
The pressure exerted by a vapour either by itself or in a mixture of gases. For example, when referring to water vapour, the vapour pressure is determined by the concentration of water vapour in the air.

VARNISH
A thickened preparation of drying oil or drying oil and resin suitable for spreading on surfaces to form continuous, transparent coatings, or for mixing with pigments to make enamels.

VENT
A pipe or duct which allows a flow of air or gas as an inlet or outlet.

VENTILATION
The provision for supplying, moving or removing air, either mechanically or naturally.

VERMICULITE
A mineral closely related to mica, with the faculty of expanding on heating to form lightweight material with insulation quality. Used as bulk insulation, as aggregate in insulating and acoustical plaster and in insulating concrete floors.

VISIBLE LIGHT
The light in the electromagnetic spectrum with wavelengths ranging from 400 (blue) to 700 (red) millimicrons.

-W-

WALL PLATES
The horizontal members in wood frame construction attached to the ends of the studs. Also called top or bottom plates, depending on their location.

WATER PROOFING
To make a surface resistant to water penetration under pressure; used where there is a definite water problem.  See also damp-proofing.

WATER-REPELLENT PRESERVATIVE
A liquid designed to penetrate into wood and impart water repellency and a moderate preservative protection. It is used for millwork, such as sash and frames, and is usually applied by dipping.

WATER TABLE
The level below which the ground is saturated with water.

WATER WALL
An interior wall of water filled containers constituting a one step heating system which combines collection
and storage.

WEATHER BARRIER
The outer most assembly of the building envelope, used to protect the inner structure and insulation from the effects of wind and rain. Materials typically used are siding, building paper and flashing.

WEATHER-STRIPPING
A strip of felt, rubber, metal or other material, fixed along the edges of doors or windows to keep out drafts and reduce heat loss.

WEEP CUT (DRIP CUT)
A groove in the underside of a horizontal board or masonry unit (such as a sill), which projects beyond the wall surface below to prevent water from moving back towards the wall surface.

WEEP HOLE
A small hole, as at the bottom of a retaining wall or masonry veneer, to drain water to the exposed face.

WIND BREAK
A hedge, fence or row of trees that serves as a protection from wind.

WIND ENERGY
The kinetic energy of air motion over the earth's surface caused by the sun's heating of the atmosphere.

WINDOW, PARTS OF
Balance : A device used to counteract the weight of the sash for ease of operation.
Light : Window pane; the term is used to designate the number of separate panes which make up the entire window.
Lintel : The horizontal top piece of the window framework.
Mullion : The perpendicular members which divide the bays or lights of windows or screen-work.
Muntin : A secondary framing member (horizontal, vertical or slanted) to hold the window panes in the sash; often confused with Mullion.
Pane : A glass surface in a window. A window may include a number of panes or may consist of a single pane.
Rough Frame : Framing of the enclosure in which the finished window frame is placed.
Sash : A light frame of wood, metal or plastic either fixed or movable which holds the glass.
Sill : The base of the window frame sloped on the outside to shed rain.

WINDOW TYPES
Awning Window : A frame containing one or more sash, each of which is installed in a vertical plane and is hinged to permit the bottom of the sash to open outward.
Bay Window : Window which projects outside the main line of a building and the compartment in which it is located.
Casement Window : A frame which contains a sash hinged at the side to open in or out.
Check Rail Window : A frame containing at least a pair of sash which are engaged when closed. The sash are installed in a vertical plane and designed to be moved either vertically or horizontally.
Clerestory Window : A window which occurs in the wall of a clerestory
Dormer Window : A vertical window in a dormer for lighting a room adjoining a sloping roof.
Double-Hung Window : A window with an upper and lower sash, each balanced by springs or weights to be capable of vertical movement with relatively little effort.
Fire Window : A window with its frame, sash and glazing which, under standard test conditions, meets the fire protection requirements for the location in which it is to be used.
Hopper Window : A frame containing one or more sash, each of which is installed in a vertical plane and hinged to permit the top of the sash to open inwards.
Jalousie Window : A frame containing a number of movable, shutter-like, overlapping glass panels.
Oriel Window : A window or group of windows that projects beyond the wall of a building and is usually carried on brackets or corbels.
Sashless Window : A window with a wood frame containing at least two lights of glass with polished or ground edges, or sash with light metal or plastic edges. At least one light of glass slides horizontally or vertically.

WOOD FRAMING
Balloon Framing : A method of wood frame construction in which the studs extend in one piece from the foundation wall to the top plate supporting the roof.
Bridging : A method used to resist twisting of joists and for stiffening floor construction by fitting either crossed pieces or solid blocks between the joists.
Cap : The upper half of the top plate in wood frame walls and partitions.
Plank Framing : A type of construction which employs flat vertical structural members with horizontal beams let into them and having an infilling of planks on edge.
Post and Beam Framing : A system of construction in which posts and beams support the loads and the infilling walls are non-load bearing.
Western Framing (Platform Framing) : A system of framing a building on which floor joists of each storey rest on the top plates of the storey below (or on the foundation sill for the first storey) and the bearing walls and partitions rest on the subfloor of each storey.

WYTHE
A continuous vertical section of a masonry wall having a thickness of one masonry unit.

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