Terminology

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


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.

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


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
A material carefully installed within a building envelope assembly to
minimize the uncontrolled passage of air into and out of a dwelling.


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

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

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

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.

ANCHOR BOLTS
The bolts securing a wooden sill plate to a concrete or masonry floor or
wall.

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.

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

ATTIC VENTS
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.

BACKDRAFTING (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.

BACK FILL
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, usually wood, steel or concrete, supported
at two or more points but not throughout its length.

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 nailheads 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 (2 inches) thick and wider than (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.


BRICK MOLDING
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.

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 molded 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

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.


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.

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 moldings.

COUNTERFLASHING
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 MOLDING
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 basementless house, 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.


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. Material used to
resist the passage of moisture through concrete floor slabs and from masonry
to wood.

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°).

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.

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.

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.


DRIP CAP
A molding 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 mold).


DRY ROT
A fungus that decays wood in the presence of moisture and warm conditions
and in the absence of light.

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.


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.

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.

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.


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 subflooring.

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 (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 (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.

FOOTCANDLE
Unit of measure of the intensity of light, defined by the light at a
distance of one foot form 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 roofplate 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.

FROSTLINE
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.


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.

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.


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 fibers 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.

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.
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-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 : Batt insulation which is held secure within framing
members by friction.
Rigid : Dense insulation material that is structurally rigid. Also called
board insulation.

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.

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.

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

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 (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 (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 (2 inches) thick and (4 inches) or more
wide.

LUMBER, DIMENSION
All yard lumber from (2 inches) to, but not including, (5
inches) thick and (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 (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.

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.

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, moldings 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.

MOLDING
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.

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.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.

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 molding 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 (8 feet) rise and (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 firstcoat.

PURLIN
The members at right angles to rafters serving to break up the roofboard
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.

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

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.


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 (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.


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

RIDGE BEAM
A horizontal structural member usually (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 fiber and saturated with asphalt, that is
supplied in (36 inch) wide rolls with a 10 square metre (100 square
feet) of material. Weights are generally (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 roofboards 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.

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 (1/2 inch) to (3/4 inch) and in widths up to
(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 (3/4 inch) thick and (6 inches) or (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 (100 sq. ft.) 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
AIL 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.
T
HERMAL 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 (5 inches).

TOENAILING
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-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.

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.


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-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.

WEATHERSTRIPPING
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.

WEEPHOLE
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. This term is 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.