Home Inspection Glossary:
Construction Terms and Definitions
A/C: An abbreviation for air conditioner.
A/C Circuit: Alternating Current. The flow of current through a conductor
first in one direction, then in reverse. It is used exclusively in residential
and commercial wiring because it provides greater flexibility in voltage selection
and simplicity of equipment design.
A/C Condenser: The outside fan unit of the air conditioning system.
It removes the heat from the Freon gas and turns the gas back into a liquid
and pumps the liquid back to the coil in the furnace.
A/C Disconnect: The main electrical ON-OFF switch near the A/C condenser.
ABS: (Acrylonitrile butadiene styrene) Rigid black plastic pipe used
only for drain lines.
Access Panel: An opening in the wall or ceiling near the fixture that
allows access for servicing the plumbing/electrical system.
Accessible: Can be approached or entered by the inspector safely, without
difficulty, fear or danger.
Acrylic: A glassy thermoplastic material that is vacuum-formed to cast
and mold shapes that form the surface of fiberglass bathtubs, whirlpools, shower
bases, and shower stalls.
Aggregate: Crushed stone, slag or water-worn gravel that comes in a
wide range of sizes which is used to surface built-up roofs.
Air Chamber: A vertical, air-filled pipe that prevents water hammer
by absorbing pressure when water is shut off at a faucet or valve.
Air Duct: Ducts, usually made of sheet metal, that carry cooled or heated
air to all rooms.
Air Filters: Adhesive filters made of metal or various fibers that are
coated with an adhesive liquid to which particles of lint and dust adhere. These
filters will remove as much as 90% of the dirt if they do not become clogged.
The more common filters are of the throwaway or disposable type.
Alarm System: Warning devices, installed or free-standing, including
but not limited to: carbon monoxide detectors, flue gas and other spillage detectors,
security equipment, ejector pumps and smoke alarms.
Algae: Microorganisms that may grow to colonies in damp environments,
including certain rooftops. They can discolor shingles. Often described as "fungus."
Alligatoring: A condition of paint or aged asphalt brought about by
the loss of volatile oils and the oxidation caused by solar radiation. Causes
a coarse checking pattern characterized by a slipping of the new paint coating
over the old coating to the extent that the old coating can be seen through
the fissures. "Alligatoring" produces a pattern of cracks resembling
an alligator hide and is ultimately the result of the limited tolerance of paint
or asphalt to thermal expansion or contraction.
Allowable Span: The distance between two supporting points for load
bearing lumber such as joists, rafters or a girder.
Aluminum Wire: A conductor made of aluminum for carrying electricity.
Aluminum is generally limited to the larger wire sizes. Due to its lower conductivity,
aluminum wire smaller than No. 12 is not made. Aluminum is lighter and less
expensive than copper, but does not conduct as well. It also breaks easily.
Ampacity: Refers to the how much current a wire can safely carry. For
example, a 12 gauge electrical copper wire can safely carry up to 20 amps.
Amperage: The rate of flow of electricity through wire - measured in
terms of amperes.
Anchor Bolts: In residential construction, bolts used to secure a wooden
sill plate to a concrete or masonry floor or wall. In commercial construction,
bolts which fasten columns, girders or other members to concrete or masonry
such as bolts used to anchor sills to masonry foundation.
Angle Iron: A piece of iron that forms a right angle and is used to
span openings and support masonry at the openings. In brick veneer, they are
used to secure the veneer to the foundation.
Anti-Siphon: A device that prevents waste water from being drawn back
into supply lines and possibly contaminating the water supply.
Approach: The area between the sidewalk and the street that leads to
a driveway or the transition from the street as you approach a driveway.
Apron: A trim board that is installed beneath a window sill.
Asbestos: A common form of magnesium silicate which was used in various
construction products due to its stability and resistance to fire. Asbestos
exposure (caused by inhaling loose asbestos fibers) is associated with various
forms of lung disease. The name given to certain inorganic minerals when they
occur in fibrous form. Though fire-resistant, its extremely fine fibers are
easily inhaled, and exposure to them over a period of years has been linked
to cancers of the lung or lung-cavity lining and to asbestosis a severe lung
impairment. A naturally occurring mineral fiber sometimes found in older homes.
It is hazardous to your health when a possibility exists of exposure to inhalable
fibers. Homeowners should be alert for friable (readily crumbled, brittle) asbestos
and always seek professional advice in dealing with it.
Asphalt: A dark brown to black highly viscous hydrocarbon produced from
the residue left after the distillation of petroleum. Asphalt is used on roofs
and highways as a waterproofing agent.
Astragal: A molding which is attached to one of a pair of swinging doors
against which the other door strikes.
Attic Access: An opening that is placed in the dry-walled ceiling of
a home providing access to the attic.
Awning Window: A window with hinges at the top allowing it to open out
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Backer Rod: In glazing, a polyethylene or polyurethane foam material
installed under compression and used to control sealant joint depth, provide
a surface for sealant tooling, serve as a bond breaker to prevent three-sided
adhesion, and provide an hourglass contour of the finished bead.
Backflow Preventer: A device or means to prevent backflow into the potable
Backhand: A simple molding sometimes used around the outer edge of plain
rectangular casing as a decorative feature.
Backsplash: A raised integral portion of a wall mount sink or lavatory
located at the rear to protect the wall.
Baffles: Device to maintain a ventilation space between the insulation
and roof, assuring air flow from the eave/soffit vents to the ridge vent or
other roof vents provided in attics and cathedral ceilings
Balusters: Usually small vertical members in a railing used between
a top rail and the stair treads or a bottom rail.
Balustrade: A railing made up of balusters, top rail, and sometimes
bottom rail, used on the edge of stairs, teal conies, and porches.
Barge Board: A decorative board covering the projecting rafter (fly
rafter) of the gable end.
Base Flashing: The upturned edge of a watertight membrane formed at
a roof termination point by the extension of the felts vertically over the cant
strip and up the wall for a varying distance where they are secured with mechanical
Base Molding: Molding used to trim the upper edge of interior baseboard.
Baseboard: Usually wood or vinyl installed around the perimeter of a
room to cover the space where the wall and floor meet. A board placed against
the wall around a room next to the floor to properly finish between the floor
and the plaster.
Baseboard Heat: A heating system with the heating unit located along
the perimeter of the wall where the baseboard would normally be located. It
can be either an electric or hot water system.
Batt Insulation: Strips of insulation, usually fiberglass, that fit
between studs or other framing.
Batten: Narrow strips of wood used to cover joints or as decorative
vertical members over plywood or wide boards.
Batter Boards: Temporary structures that hold strings used to locate
and square the corners of a building.
Bay Window: Any window space projecting outward from the walls of a
building, either square or polygonal in plan.
Bead: In glazing, an applied sealant in a joint irrespective of the
method of application, such as caulking bead, glazing bead, etc. Also a molding
or stop used to hold glass or panels in position.
Beam: A supporting member either of wood or steel. Structural support
member (steel, concrete, lumber) transversely supporting a load that transfers
weight from one location to another.
Bearing Wall: A wall that supports any vertical load in addition to
its own weight.
Bed Molding: A molding in an angle, as between the over hanging cornice
or eaves of a building and the side walls.
Bedrock: A subsurface layer of earth that is suitable to support a structure.
Bevel Siding (or Lap Siding): Wedge-shaped boards used as horizontal
siding in a lapped pattern. This siding varies in butt thickness from ½
to ¾ inch and in widths up to 12 inches. Normally used over some type
Bifold Door: Doors that are hinged in the middle to allow them to open
in a smaller area than standard swing doors. Often used for closet doors.
Bird's-Mouth Cut: A cutout in a rafter where it crosses the top plate
of the wall providing a bearing surface for nailing. Also called a heel cut.
Blind Nailing: Nailing in such a way that the nail heads are not visible
on the face of the workusually at the tongue of matched boards.
Blister: An enclosed raised spot evident on the surface of a building.
They are mainly caused by the expansion of trapped air, water vapor, moisture
or other gases.
Blower Door Test: A method to measure how tightly a home is sealed by
increasing the air pressure inside a home in relation to the outside.
Board and Batten: A method of siding in which the joints between vertically
placed boards or plywood are covered by narrow strips of wood.
Board Foot: The volume of a piece of wood measuring 12 inches square
and one inch thick.
Bottom Chord: The lower or bottom horizontal member of a truss.
Bottom Plate: The 2x4s or 6s that lay on the subfloor upon which the
vertical studs are installed.
Branch Circuit (Electrical): Wiring that runs from a service panel or
sub-panel to outlets. Branch circuits are protected by fuses or breakers at
Breaker Box: A metal box that contains circuit breakers or fuses that
control the electrical current in a home.
Breaker Panel: The electrical box that distributes electric power entering
the home to each branch circuit (each plug and switch) and composed of circuit
Breeze Way: A roofed, open-sided passageway connecting two structures,
such as a house and a garage.
Brick Lintel: The metal angle iron that brick rests on, especially above
a window, door, or other opening.
Brick Mold: Trim used around an exterior door jamb onto which siding
Brick Tie: A small, corrugated metal strip (1"x6"- 8"
long) nailed to wall sheeting or studs. They are inserted into the grout mortar
joint of the veneer brick, and hold the veneer wall to the sheeted wall behind
Brick Veneer: A facing of brick laid against and fastened to the sheathing
of a frame wall or tile wall construction.
Bridging: Small wood or metal members that are inserted in a diagonal
position between the floor joists at midspan to act as both tension and compression
members for the purpose of bracing the joists a spreading the action of loads.
BTU: A measure of the capacity of a heating or cooling system. Abbreviation
of British Thermal Unit. The amount of heat energy required to raise the temperature
of one pound of water through a change of one degree Fahrenheit.
Building Paper: A general term for papers, felts and similar sheet materials
used in buildings without reference to their properties or uses. Generally comes
in long rolls.
Building Permit: Written authorization from the city or other governing
regulatory body giving permission to construct or renovate a building. A building
permit is specific to the building project described in the application.
Built-Up Roof: A roofing composed of three to five layers of asphalt
felt laminated with coal tar, pitch, or asphalt. The top is finished with crushed
slag or gravel. Generally used on flat or low-pitched roofs.
Bundle: A package of shingles. There are 3, 4 or 5 bundles per square.
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Caisson: A 10" or 12" diameter hole drilled into the earth
and embedded into bedrock 3 - 4 feet. The structural support for a type of foundation
wall, porch, patio, monopost, or other structure. Two or more "sticks"
of reinforcing bars (rebar) are inserted into and run the full length of the
hole and concrete is poured into the caisson hole.
Camber Windows: Casement windows with a curved top.
Cant Strip: A beveled support used at the junction of a flat surface
and a vertical surface to prevent bends and/or cracking of the roofing membrane
at the intersection of the roof deck and wall. Used with a base flashing to
minimize breaking of the roofing felts.
Cantilever: A projecting beam or other structure supported only at one
end. Any part of a structure that projects beyond its main support and is balanced
Cap Flashing: The portion of the flashing attached to a vertical surface
to prevent water from migrating behind the base flashing.
Capital: The head or crowning feature of a column.
Carbon Monoxide: CO. A colorless, odorless, highly poisonous gas formed
by the incomplete combustion of carbon.
Casement Window: A sidehinged window that opens on hinges secured to
the side of the window frame.
Casing: Molding of various widths and thickness' used to trim door and
window openings at the jambs.
Cast-Iron Pipe (Plumbing): Drain and vent lines. Most older drain-waste
venting systems are made of cast-iron pipes. Now increasingly supplanted by
ABS and PVC. Pipes were originally joined with molten lead, but most plumbers
now join them with no-hub couplers.
Catch Basin: A drain for a low or wet spot, with pipe exiting the side
and a pit at the bottom to collect sediment.
Caulk: The application of sealant to a joint, crack or crevice. A compound
used for sealing that has minimum joint movement capability; sometimes called
low performance sealant.
CCA (Chromated Copper Arsenate): A pesticide that is forced into wood
under high pressure to protect it from termites, other wood boring insects,
and decay caused by fungus.
Ceiling Joist: One of a series of parallel framing members used to support
ceiling loads and supported in turn by larger beams, girders or bearing walls.
Cellulose Insulation: Ground-up newspaper that is treated with a fire
retardant and pest resistant.
Celsius (formerly Centigrade): A thermometric scale in which the freezing
point of water is 0°C and its boiling point 100°C at normal sea level
atmospheric pressure (14.7 psi).
Cement Mixtures: Rich - 1 part cement, 2 parts sand, 3 parts coarse
aggregate. Used for concrete roads and waterproof structures. Standard - 1 part
cement, 2 parts sand, 4 parts coarse aggregate. Used for reinforced work floors,
roofs, columns, arches, tanks, sewers, conduits, etc. Medium - 1 part cement,
2 1/2 parts sand, 5 parts coarse aggregate. Used for foundations, walls, abutments,
piers, etc. Lean - 1 part cement, 3 parts sand, 6 parts coarse aggregate. Used
for all mass concrete work, large foundations, backing for stone masonry, etc.
Mixtures are always listed Cement to Sand to Aggregate.
Centerset: A style of faucet that is installed on a lavatory with 4"
center-to-center faucet holes and that has the spout and handle(s) combined
into a single part.
Ceramic Tile: A man-made or machine-made clay tile used to finish a
floor or wall. Generally used in bathtub and shower enclosures and on counter
Certificate of Occupancy: A document stating that a building is approved
for occupancy. The Building Authority issues the Certificate of Occupancy.
Chair Rail Moulding: A wooden molding placed along the lower part of
the wall to prevent chairs, when pushed back, from damaging the wall. Also used
Chase: A framed enclosed space around a flue pipe or a channel in a
wall or through a ceiling for something to lie in or pass through.
Checking: Fissures that appear with age in many exterior paint coatings.
At first superficial, but in time may penetrate entirely through the coating.
It produces a pattern of surface cracks running in irregular lines. When found
in the top pour of an asphalt built-up roof, checking is the preliminary stage
Chemical Injection Grouting: Leak repair technique usually used below
grade in cracks and joints in concrete walls and floors that involves the injection
of sealant (usually urethane) that reacts with water to form a seal.
Chink: To install fiberglass insulation around all exterior door and
window frames, wall corners, and small gaps in the exterior wall.
Chip Board: A manufactured wood panel made out of 1"- 2" wood
chips and glue. Often used as a substitute for plywood in the exterior wall
and roof sheathing. Also called OSB (Oriented Strand Board) or Wafer Board.
Circuit: A network of wiring that typically commences at a panel box,
feeds electricity to outlets and ultimately returns to the panel box.
Circuit Breaker: A protective device which automatically opens an electrical
circuit when it is overloaded.
Cistern: Reservoir for water. Common in houses built prior to the fifties
in the Midwest.
Clapboard: Overlapping horizontal boards that cover the timber-framed
wall of a house.
Class B Door: A fire resistant rating applied by the Underwriters Laboratories
Classification for a door having a 1 to 1 1/2 hour rating.
Cleanout: A plug in a trap or drain pipe that provides access for the
purpose of clearing an obstruction.
Cleanout (Plumbing): A drain fitting, usually a wye or a tee, with a
removable plug to permit inspection and access for an auger or snake.
Cleat: A wedge-shaped piece (usually of metal) which serves as a support
or check. A strip fastened across something to give strength or hold something
Closed Cut Valley: A method of valley treatment in which shingles from
one side of the valley extend across the valley, while shingles from the other
side are trimmed 2 inches from the valley centerline. The valley flashing is
Coal Tar Pitch: A bituminous material, which is a byproduct from the
coking of coal. It is used as the waterproofing material for tar and gravel
Collar Tie: A horizontal board attached perpendicular to rafters.
Combustion Air: The duct work installed to bring fresh, outside air
to the furnace and/or hot water heater. Normally 2 separate supplies of air
are brought in: one high and one low.
Combustion Chamber: The part of a boiler, furnace or woodstove where
the burn occurs; normally lined with firebrick or molded or sprayed insulation.
Common Rafter: Rafter that extends from the top plate to the ridge.
Generally set 12, 16, or 24 inches apart.
Compression Fitting: Used to join or connect pipes and conduit by causing
a ring to compress against the connecting tube when tightening with a wrench.
Compression Web: A member of a truss system which connects the bottom
and top chords and which provides downward support.
Compressor: A mechanical device that pressurizes a gas in order to turn
it into a liquid, thereby allowing heat to be removed or added. A compressor
is the main component of conventional heat pumps and air conditioners. In an
air conditioning system, the compressor normally sits outside and has a large
fan (to remove heat).
Concrete Board: A panel made out of concrete and fiberglass usually
used as a tile backing material.
Condensate Line: The copper pipe that runs from the outside air conditioning
condenser to the inside furnace ( where the A/C coil is located).
Condensation: Changing a substance from a vapor to a liquid state by
removing the heat. The condensate shows up on surfaces as a film or drops of
water. Normal in areas of high humidity, usually controlled by ventilation or
Condensing Unit: The outdoor component of a cooling system. It includes
a compressor and condensing coil designed to give off heat.
Conditioned Space: A conditioned space is the part of the building that
is designed to be thermally conditioned for the comfort of occupants or for
other occupancies or for other reasons.
Conduit: A hollow pipe casing through which electric lines run.
Copper Pipe Types: Type K has the heaviest or thickest wall and is generally
used underground. It has a green stripe. Type L has a medium wall thickness
and is most commonly used for water service and for general interior water piping.
It has a blue stripe. Type M has a thin wall and many codes permit its use in
general water piping installation. It has a red stripe.
Corbel Out: To build out one or more courses of brick or stone from
the face of a wall to form a support for timbers.
Corinthian Column: A column decorated at the top with a mixed bag of
curlicues, scrolls and other lavish ornamentation.
Corner Bead: A strip of formed sheet metal, sometimes combined with
a strip of metal lath, placed on corners before plastering to reinforce them.
Cornice: Any projecting ornamental molding that finishes or crowns the
top of a building, wall, arch, etc.
Counter Flashing: The formed metal secured to a wall, curb, or roof
top unit to cover and protect the upper edge of a base flashing and its associated
fasteners. This type of flashing is usually used in residential construction
on chimneys at the roofline to cover shingle flashing and to prevent moisture
Cove Molding: A molding with a concave face used as trim or to finish
CPVC (Chlorinated Polyvinyl Chloride): Rigid plastic pipe used in water
Crawlspace Vents: An opening to allow the passage of air through the
unfinished area under a first floor. Ideally there should be at least two vents
Cross Bridging: Small wood pieces placed at angles so that they extend
from the bottom of one floor joist to the top of the adjacent joist to add stability
to the structural members. Diagonal bracing between adjacent floor joists, placed
near the center of the joist span to prevent joists from twisting.
Cricket: A peaked saddle construction at the back of a chimney to prevent
accumulation of snow and ice and to deflect water around the chimney.
Cripple Walls: In a wood-frame house, the section of wall under the
house between the concrete foundation and the floor joists.
Crown Molding: A molding used on cornice or wherever an interior angle
is to be covered.
Cupola: A dome, especially a small dome on a circular or polygonal base
crowning a roof or turret. Usually only decorative in modern homes. Older cupolas
can be reached by stairs.
Curtain Drain: A ditch sometimes filled with gravel and a drain tile
which diverts storm and drain water away from a structure.
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Damper: An air valve that regulates the flow of air inside the flue
of a furnace or fireplace.
Dew Point: Temperature at which vapor condenses from the atmosphere
and forms water.
Doric Column: A Greek-style column with only a simple decoration around
the top, usually a smooth or slightly rounded band of wood, stone or plaster.
Dormer: Dormer comes from the French word dormir, which means to
sleep. Dormers are located on the second floor, usually in bedrooms or
bathrooms, and project through the roof to provide a window in this space.
Double Hung Window: A window with sashes that slide vertically and allow
opening from the top and bottom. Both lower and upper sashes can move up or
Drainage Plane: Drainage planes are water repellent materials (building
paper, housewrap, foam insulation, etc.) which are typically located behind
the cladding and are designed and constructed to drain water that passes through
the cladding. They are interconnected with flashings, window and door openings,
and other penetrations of the building enclosure to provide drainage of water
to the exterior of the building. The materials that form the drainage plane
overlap each other shingle fashion or are sealed so that water drains down and
out of the assembly.
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.
Drip Edge: A device designed to prevent water from running back or under
Drywall: A gypsum board material used for walls or ceilings.
Ductwork: A system of distribution channels used to transmit heated
or cooled air from a central system (HVAC) throughout a home.
Dura Board, Dura Rock: A panel made out of concrete and fiberglass usually
used as a ceramic tile backing material. Commonly used on bathtub decks. Sometimes
called Wonder Board.
DWV (Drainage, Waste & Vent): The pipes in a plumbing system that
remove waste water.
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Earthquake Strap: A metal strap used to secure gas hot water heaters
to the framing or foundation of a house. It is intended to reduce the chances
of having the water heater fall over in an earthquake and causing a gas leak.
Eave: The part of the roof which extends beyond the side wall. Made
up of both the soffit and the fascia.
Efflorescence: A white powder on the surface of walls due to evaporation
of water. It forms on the surface of bricks.
EIFS: Exterior Insulating and Finish System; exterior wall cladding
system consisting primarily of polystyrene foam board with a textured acrylic
finish that resembles plaster or stucco.
Energy Efficiency Ratio: An air conditioning efficiency rating system
which indicates the number of BTU's delivered per watt of power consumed.
EPDM (Ethylene Propylene Diene Monomer): A single ply roofing membrane
consisting of synthetic rubber; usually 45 or 60 mils. Application can be ballasted,
fully adhered or mechanically attached.
Escutcheon: A trim piece or decorative flange that fits beneath the
faucet handle to conceal the faucet stem and the hole in the fixture or wall.
Eave Vents: Vent openings located in the soffit under the eaves of a
house to allow the passage of air through the attic and out the roof vents.
Exhaust Fan: Extracts air or excess heat from the interior of a home.
Expansion Joint: A device used to permit a structure to expand or contract
without breakage. In residential construction, a bituminous fiber strip used
to separate blocks or units of concrete to prevent cracking due to expansion
as a result of temperature changes. Also used on concrete slabs.
Exposed Aggregate Finish: A method of finishing concrete which washes
the cement/sand mixture off the top layer of the aggregate - usually gravel.
Often used in driveways, patios and other exterior surfaces.
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Fahrenheit: A thermometric scale in which 32°F denotes freezing
and 212°F the boiling point of water under normal sea level atmospheric
pressure of 14.7 psi.
Fanlight: A window, often semicircular, with radiating glazing bars
suggesting a fan that is placed over a door.
Fascia: A horizontal piece (such as a board) covering the joint between
the top of a wall and the projecting eaves.
Fiber Glass Insulation: An energy-efficient glass fiber product installed
in floors, walls and attics. Comes in batts and can be blown in.
Finial: A formal ornament at the top of a canopy, gable, pinnacle, etc.
Fluting: Shallow, concave grooves running vertically on the shaft of
a column, pilaster or other surface.
Foyer: The entrance hall of a home.
Furring Strips: Flat pieces of lumber used to build out framing to an
even surface, either the leveling of a part of a wall or ceiling. In block or
concrete construction, they may be used as a means of attaching the interior
or exterior finish.
Fascia: A flat, horizontal board enclosing the overhang under the eave.
Fasteners: A general term covering a wide variety of screws and nails,
which may be used for mechanically securing various components of a building.
Faucet: A device for regulating the flow of water.
Ferrule: Metal tubes used to keep roof gutters "open." Long
nails (ferrule spikes) are driven through these tubes and hold the gutters in
place along the fascia of the home.
Finger Joint: A manufacturing process of interlocking two shorter pieces
of wood end to end to create a longer piece of dimensional lumber or molding.
Often used in jambs and casings and normally painted (instead of stained).
Fire Brick: Brick made of refractory ceramic material which will resist
high temperatures. Used in fireplaces and boilers.
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 2x4s cross blocking between studs.
Flash Point: The critical temperature at which a material will ignite.
Flashing: Material used around any angle in a roof or wall to prevent
Flue: A pipe used to exhaust smoke, gas or air.
Flue Damper: An automatic door located in the flue that closes it off
when the burner turns off; its purpose is to reduce heat loss up the flue from
the still-warm furnace or boiler.
Flue Lining: Fire clay or terra-cotta pipe, round or square, usually
made in all ordinary flue sizes and in 2-foot lengths, used for the inner lining
of chimneys with the brick or masonry work around the outside. Flue lining in
chimneys runs from about a foot below the flue connection to the top of the
Fly Rafters: End rafters of the gable overhang supported by roof sheathing
Footings: Wide pours of cement reinforced with re-bar (reinforcing bar)
that support foundation walls, pillars, or posts. Footings are part of the foundation
and are often poured before the foundation walls.
Forced Air Heating: A common form of heating with natural gas, propane,
oil or electricity as a fuel. Air is heated in the furnace and distributed through
a set of metal ducts to various areas of the house.
Form: Temporary structure erected to contain concrete during placing
and initial hardening.
Foundation: The supporting portion of a structure below the first floor
construction, or below grade, including the footings.
Foundation Coating: High-quality below-grade moisture protection. Used
for below-grade exterior concrete and masonry wall damp-proofing to seal out
moisture and prevent corrosion.
French Door: A tall casement window that reaches to the floor and opens
like a door. It is a popular accent that brings more light into a home.
Frieze: A decorated band along the upper part of an interior wall.
Friezeboard: Trim work that follows the eve horizontally below the soffit
on the wall.
Fully Tempered Glass: Fully tempered glass, if broken, will fracture
into many small pieces (dice) which are more or less cubical. Fully tempered
glass is approximately four times stronger than annealed glass of the same thickness
when exposed to uniform static pressure loads.
Fungi (Wood): Microscopic plants that live in damp wood and cause mold,
stain, and decay.
Fungicide: A chemical that is poisonous to fungi.
Furnace: A heating system that uses the principle of thermal convection.
When air is heated, it rises and as the air cools it settles. Ducts are installed
to carry the hot air from the top of the furnace to the rooms. Other ducts,
called cold air returns, return the cooler air back to the furnace.
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Gable: The end of a building as distinguished from the front or rear
side. The triangular end of an exterior wall from the level of the eaves to
the ridge of a double-sloped roof. In house construction, the portion of the
roof above the eave line of a double-sloped roof.
Gable End Walls: The triangular end of an exterior wall above the eaves.
Gable Roof: A roof that consists of two sloping planes that meet at
the ridge (peak). The planes are supported at their ends by triangular, upward
extensions of walls known as gables.
Gable Vents: A louver vent mounted in the top of the gable to allow
the passage of air through the attic.
Gambrel Roof: A type of roof which has its slope broken by an obtuse
angle, so that the lower slope is steeper than the upper slope. A double sloped
roof having two pitches.
Gang Nail Plate: A steel plate attached to both sides at each joint
of a truss. Sometimes called a Fishplate or Gusset.
Gargoyle: A figurine that projects from a roof or the parapet of a wall
or tower and is carved into a grotesque figure, human or animal.
Gate Valve: A valve that lets you completely stop, but not modulate,
the flow within a pipe.
Gazebo: A small lookout tower or summerhouse with a view, usually in
a garden or park, but sometimes on the porch or roof of a house; also called
GFI or GFCI (Ground Fault Circuit Interrupters): Special devices capable
of opening a circuit when even a small amount of current is flowing through
the grounding system.
Globe Valve: A valve that lets you adjust the flow of water to any rate
between fully on and fully off. Also see Gate Valve.
Gloss (Paint or Enamel): A paint or enamel that contains a relatively
low proportion of pigment and dries to a sheen or luster.
Glued Laminated Beam (Glulam): A structural beam composed of wood laminations
or lams. The lams are pressure bonded with adhesives to attain a typical thickness
of 1 ½" . (It looks like 5 or more 2x4s are glued together).
GPF (Gallons Per Flush): The unit of measurement by which flow rate
of toilets are measured.
GPM (Gallons Per Minute): The unit of measurement by which the flow
rate of faucets and showerheads is measured.
Grade Beam: A foundation wall that is poured level with or just below
the grade of the earth. An example is the area where the 8' or 16' overhead
garage door "block out" is located, or a lower (walk out basement)
foundation wall is poured.
Grain: The direction, size, arrangement, appearance, or quality of the
fibers in wood.
Granules: The mineral particles of a graded size which are embedded
in the asphalt coating of shingles and roofing.
Grid: The completed assembly of main and cross tees in a suspended ceiling
system before the ceiling panels are installed. Also the decorative slats (munton)
installed between glass panels.
Ground: Refers to electricity's habit of seeking the shortest route
to earth. Neutral wires carry it there in all circuits. An additional grounding
wire or the sheathing of the metal-clad cable or conduit protects against shock
if the neutral leg is interrupted.
Ground Cover: A light covering of plastic film or similar material used
over the soil in crawl spaces of buildings to minimize moisture permeation of
Grounding Rod: Rod used to ground an electrical panel.
Grout: A hydrous mortar whose consistency allows it to be placed or
pumped into small joints or cavities, as between pieces of ceramic clay, slate,
Gunite: A construction material composed of cement, sand or crushed
slag and water mixed together and forced through a cement gun by pneumatic pressure,
used in the construction of swimming pools.
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: Metal or wood trough at the eaves of a roof to carry rain water
from the roof to the downspout.
Gypsum Plaster: Gypsum formulated to be used with the addition of sand
and water for base-coat plaster.
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H Clip: Small metal clips formed like an "H" that fits at
the joints of two plywood (or wafer board) sheets to stiffen the joint. Normally
used on the roof sheeting.
Half-timbering: A method of construction featuring walls built of timber
framework with the spaces filled in by plaster or brickwork. Often, some of
the exposed planks are laid at an angle to create a pattern. In modern homes,
half-timbering is usually not authentic, used only as decoration in small areas.
Handicap Accessible: This refers to any house plan that has made definite
provisions for people with mobility problems. Including but not limited to grab
bars, wider doors and hallways, wheel chair maneuvering space, etc.
Hardware: Metal accessories such as door knobs, towel bars, toilet paper
Hatch: An opening in a deck, floor or roof. The usual purpose is to
provide access from inside the building.
Header: A brick laid in a wall so that only its end appears on the face
of the wall. To add a varied appearance to brickwork, headers are alternated
with "stretchers," bricks laid full length on their sides.
Header: Framing members over windows, doors, or other openings. A beam
placed perpendicular to joists and to which joists are nailed in framing for
chimney, stairway, or other opening. Also, a wood lintel.
Hearth: The inner or outer floor of a fireplace, usually made of brick,
tile, or stone.
Heat Pump: A device which uses compression and decompression of gas
to heat and/or cool a house.
Heel Cut: A notch cut in the end of a rafter to permit it to fit flat
on a wall and on the top, doubled, exterior wall plate.
Hermetic Seal: Vacuum seal between panes of a double-paned window, i.e.
insulated glass unit or IGU. Failure of a hermetic seal causes permanent fogging
between the panels of the IGU.
Herringbone: Stone, brick or tile work in which the components are laid
diagonally instead of horizontally, forming a distinctive zigzag pattern along
a wall face or often seen on the floors of decks.
Hip: The external angle formed by the meeting of two sloping sides of
Hip Rafter: A rafter that forms the intersection of an external roof
Hip Roof: A roof that rises by inclined planes from all four sides of
a building. A roof with sloped instead of vertical ends.
Honeycomb: Areas in a foundation wall where the aggregate (gravel) is
visible. Honeycombs can be usually be remedied by applying a thin layer of grout
or other cement product over the affected area. Also, a method by which concrete
is poured and not puddled or vibrated, allowing the edges to have voids or holes
after the forms are removed.
Hopper: Crank windows, hinged on the bottom, that open outward from
Hose Bib: An outdoor faucet with hose threads on the spout. Also commonly
used to supply washing machines and wash basins.
Hot Wire: The wire that carries electrical energy to a receptacle or
other devicein contrast to a neutral, which carries electricity away again.
Normally the black wire.
Housewrap: Any of the numerous spun-fiber polyolefin rolled sheet goods,
or perforated plastic films designed to function as drainage planes.
Humidifier: A device designed to increase the humidity within a room
or a house by means of the discharge of water vapor. They may consist of individual
room size units or larger units attached to the heating plant to condition the
Hurricane Clip: Metal straps that are nailed and secure the roof rafters
and trusses to the top horizontal wall plate.
Hurricane Ties: Metal fasteners used to secure rafters in structures
subject to hurricane winds.
HVAC: Heating Ventilation and Air Conditioning.
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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.
I.C. or Insulated Ceiling: Marking on recessed lighting fixtures indicating
that they are designed for direct insulation contact.
I-Joist: Manufactured structural building component resembling the letter
"I." Used as floor joists and rafters. I-joists include two key parts:
flanges and webs. The flange of the I joist may be made of laminated veneer
lumber or dimensional lumber, usually formed into a 1 ½" width.
The web or center of the I-joist is commonly made of plywood or oriented strand
board (OSB). Large holes can be cut in the web to accommodate duct work and
plumbing waste lines. I-joists are available in lengths up to 60 feet long.
Inside Drain: In roofing, a drain positioned on a roof at some location
other than the perimeter. It drains surface water inside the building through
closed pipes to a drainage system.
Insulation: Generally, any material which slows down or retards the
flow or transfer of heat. Building insulation types are classified according
to form as loose-fill, flexible, rigid, reflective, and foamed-in-place. All
types are rated according to their ability to resist heat flow (R-Value). In
electrical contracting, rubber, thermoplastic, or asbestos wire covering. The
thickness of insulation varies with wire size and type of material, application
or other code limitations.
Ionic Column: A Greek-style column topped by a single scroll just below
Interlocking Shingles: Individual shingles that mechanically fasten
to each other to provide wind resistance.
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J Channel: Metal edging used on drywall to give the edge a better finished
appearance when a wall is not "wrapped." Generally, basement stairway
walls have drywall only on the stair side. J Channel is used on the vertical
edge of the last drywall sheet.
Jack Post: A type of structural support made of metal which can be raised
or lowered through a series of pins and a screw to meet the height required.
Basically used as a replacement for an old supporting member in a building.
Jack Rafter: A rafter that spans the distance from the wall plate to
a hip, or from a valley to a ridge.
Jamb: The side and head lining of a doorway, window, or other opening.
Joist: Horizontal framing member set from wall to wall to support the
floor or ceiling.
Joist Hanger: A metal "U" shaped item used to support the
end of a floor joist and attached with hardened nails to another bearing joist
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Keyway: A slot formed and poured on a footer or in a foundation wall
when another wall will be installed at the slot location. This gives additional
strength to the joint/meeting point.
Kiln-dried Lumber: Any lumber placed in a heated chamber or "shed"
to reduce its moisture content to a specified range or average under controlled
conditions. For softwood framing lumber, the moisture content of KD lumber is
somewhat based on regional conventions but is most often an average of 12% by
weight. In comparison, the moisture content of thoroughly air-dried softwood
framing lumber is 15% to 20%.
Kilowatt (KW): One thousand watts. A kilowatt hour is the base unit
used in measuring electrical consumption. Also see Watt.
Knee Walls: Walls of varying length. Used to provide additional support
to roof rafters with a wide span or to finish off an attic.
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Landing: A platform between flights of stairs or at the termination
of a flight of stairs.
Lateral (Electric, Gas, Telephone, Sewer and Water): The underground
trench and related services (i.e., electric, gas, telephone, sewer and water
lines) that will be buried within the trench.
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.
Lath and Plaster: The most common wall finish prior to the introduction
of drywall. Thin wood strips (lath) were nailed onto the framing as a base for
the sand/lime plaster.
Lattice: A framework of crossed wood or metal strips.
Lavatory: Bathroom or washroom sink.
Lead: A malleable metal once extensively used for flashings.
Lead Based Paint: Lead is a highly toxic metal that was used for many
years in products found in and around our homes. Lead may cause a range of health
effects, from behavioral problems and learning disabilities, to seizures and
death. Children 6 years old and under are most at risk, because their bodies
are growing quickly.
Ledger Strip: A strip of lumber nailed along the bottom of the side
of a girder on which joists rest.
Limit Switch: A safety control that automatically shuts off a furnace
if it gets too hot. Most also control blower cycles.
Lineal Foot: A unit of measure for lumber equal to 1 inch thick by 12
inches wide by 12 inches long. Examples: 1" x 12" x 16' = 16 board
feet, 2" x 12" x 16' = 32 board feet.
Lintel: A horizontal structural member that supports the load over an
opening such as a door or window.
Live Load: Loads produced by use and occupancy of the building or other
structure and do not include construction or environmental loads such as wind
load, snow load, ice load, rain load, seismic load, or dead load.
Load Bearing Wall: A wall which is supporting its own weight and some
other structural elements of the house such as the roof and ceiling structures.
Load bearing walls carry the load from above, down to the foundation. Load bearing
walls brace from the floor to the roof.
Lookout: A short wood bracket or cantilever to support an overhang portion
of a roof or the like, usually concealed from view.
Louver: An opening with a series of horizontal slats arranged so as
to permit ventilation but to exclude rain, sun, light, or vision. See also Attic
Low-E: Most often used in reference to a coating for high-performance
windows, the "e" stands for emissivity or re-radiated heat flow. The
thin metallic oxide coating increases the U-value of the window by reducing
heat flow from a warm(er) air space to a cold(er) glazing surface. The best
location for the coating is based on whether the primary heat flow you want
to control is from the inside out (heating climates) or the outside in (cooling
Low-Slope Application: Method of installing asphalt shingles on roof
slopes between 2 and 4 inches per foot.
Lumens: Unit of measure for total light output. The amount of light
falling on a surface of one square foot.
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Mansard Roof: A roof which rises by inclined planes from all four sides
of a building. The sloping roofs on all four sides have two pitches, the lower
pitch usually very steep and the upper pitch less steep. This roof is flat on
top, sloping steeply down on all four sides.
Mantel: The shelf above a fireplace. Also used in referring to the decorative
trim around a fireplace opening.
Masonry: Stone, brick, concrete, hollow-tile, concrete block or other
similar building units or materials or a combination of the same, bonded together
with mortar to form a wall, pier, buttress, or similar mass.
Mechanical Ventilation: Controlled, purposeful introduction of outdoor
air to the conditioned space.
Metal Lath: Sheets of metal that are slit and drawn out to form openings.
Used as a plaster base for walls and ceilings and as reinforcing over other
forms of plaster base.
Microlam: A manufactured structural wood beam. It is constructed of
pressure and adhesive bonded wood strands of wood. They have a higher strength
rating than solid saw lumber. Normally comes in l ½" thickness'
and 9 ½", 11 ½" and 14" widths.
Millwork: Generally 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 doorframes, blinds, porchwork, mantels, panelwork, stairways, moldings,
and interior trim. It normally does not include flooring, ceiling, or siding.
Mineral-Surfaced Roofing: Asphalt shingles and roll roofing that are
covered with granules.
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.
Mixing Valve: A valve that mixes hot and cold water in the valve to
obtain a set temperature prior to delivery.
Mobile Home Aluminum Roof Coating: Durable one-coat application prolongs
the life of mobile home roofs while reflecting sun's rays and providing a decorative
surface. Reduces energy costs.
Moisture Meter: A device used to detect moisture by measuring slowed,
Molding: A wood strip having a coned or projecting surface used for
decorative purposes, e.g., door and window trim.
Mopping: In roofing, a layer of hot bitumen mopped between plies of
Mortar Types: Type M is suitable for general use and is recommended
specifically for masonry below grade and in contact with earth, such as foundations,
retaining walls and walks. Type M is the strongest type. Type S is suitable
for general use and is recommended where high resistance to lateral forces is
required. Type N is suitable for general use in exposed masonry above grade
and is recommended specifically for exterior walls subject to severe exposures.
Type O is recommended for load-bearing walls of solid units where the compressive
stresses do not exceed 100 lbs. per square inch and the masonry wall not be
subjected to freezing and thawing in the presence of excessive moisture.
Mortise: A slot cut into a board, plank, or timber, usually edgewise,
to receive tenon of another board, plank, or timber to form a joint.
Mudsill: A wood foundation member, usually a pressure treated 2x4 or
2x6, bolted to the foundation and on which other framing members can be attached.
Mullion: A vertical bar or divider in the frame between windows, doors,
or other openings that supports and holds such items as panels, glass, sash.
Muntins: Horizontal or vertical bars that divide the sash frame into
smaller lights of glass. Muntins are smaller in dimensions and weight than mullions.
Muriatic Acid: Commonly used as a brick cleaner after masonry work is
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Nailer: A piece of lumber secured to non-nailable decks and walls by
bolts or other means, which provides a suitable backing onto which roof components
may be mechanically fastened.
Natural Finish: A transparent finish which does not seriously alter
the original color or grain of the natural wood. Natural finishes are usually
provided by sealers, oils, varnishes, water-repellent preservatives, and other
Newel: A post to which the end of a stair railing or balustrade is fastened.
Also, any post to which a railing or balustrade is fastened..
Non-Bearing Wall: A wall supporting no load other than its own weight.
Nosing: The projecting edge of a molding or drip. Usually applied to
the projecting molding on the edge of a stair tread.
Oakum: Loose hemp or jute fiber that is impregnated with tar or pitch
and used to caulk large seams or for packing plumbing pipe joints.
On Center (O.C.): A measurement term meaning a certain distance between
like materials. Studs rafters, joists, and the like in a building placed at
16 inches O.C. will be laid out so that there is 16 inches from the center of
one stud to the center of the next.
Open Valley: Method of valley construction in which shingles on both
sides of the valley are trimmed along a chalk line snapped on each side of the
valley. Shingles do not extend across the valley. Valley flashing is exposed.
Oriented Strand Board (OSB, Chip Board, Wafer Board): A manufactured
wood panel made out of 1"- 2" wood chips and glue. Often used as a
substitute for plywood in the exterior wall and roof sheathing.
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.
Overhang: That part of the roof structure which extends horizontally
beyond the vertical plane of the exterior walls of a building.
Ozone: 03 instead of 02. This 3-atom molecule is an even more active
oxidizing agent than its more common 2-atom relative. At ground level, ozone
is a pollutant and in the upper atmosphere it is a solar shield (location, location,
location). Touted for its ability to "clean" air in room or household
ozone generators, this application actually does more harm than good-ozone's
highly reactive nature tends to accelerate the breakdown of synthetic materials
in homes such as paints, plastics, and ever-available volatile organic compounds,
often with less-than-desirable results. All told, we look to protect ozone in
the heavens and shun it here at home, inside and out.
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P Trap: P-shaped section of drain pipe that prevents sewer odors from
escaping into your home. Water is trapped in the pipe blocking gases from escaping
through the drain.
Paint: A combination of pigments with suitable thinners or oils to provide
decorative and protective coatings.
Palladian Window: One larger window with a circle top window above and
flanked by two smaller, rectangular windows. These are usually fixed windows.
Panel: In house construction, a thin flat piece of wood, plywood, or
similar material, framed by stiles and rails as in a door or fitted into grooves
of thicker material with molded edges for decorative wall treatment.
Parapet Wall: A low wall around the perimeter of a roof deck.
Parge Coat: A thin application of plaster for coating a wall.
Parquet Flooring: Flooring of thin hardwood laid in patterns on a wood
subfloor. Inlaid parquet consists of a veneer of decorative hardwood glued in
patterns to squares of softwood backing, then laid on a subfloor.
Patio: Paved recreation area, usually at the rear of a home.
Patterned Glass: A type of rolled glass having a pattern impressed on
one or both sides. Used extensively for light control, bath enclosures and decorative
glazing. Sometimes call "rolled," "figured," or "obscure"
Paver Stones: Usually pre-cast concrete slabs used to create a traffic
Pedestal: The base supporting a column or colonnade.
Pedestal Lavatory: A lavatory in which the bowl is supported by a single
Pediment: A feature above doors in homes. It may be straight or curved,
"broken'' in the center, or solid
Penthouse: A relatively small structure built above the plane of the
Perimeter Drain: 3" or 4" perforated plastic pipe that goes
around the perimeter (either inside or outside) of a foundation wall (before
backfill) and collects and diverts ground water away from the foundation. Generally,
it is "daylighted" into a sump pit inside the home, and a sump pump
is sometimes inserted into the pit to discharge any accumulation of water.
Permeance: The physical property that defines the ease at which water
molecules diffuse through a material. It is to vapor diffusion what conductance
is to heat transfer. The unit of measurement is typically the "perm."
Pier: A column of masonry, usually rectangular in horizontal cross section,
used to support other structural members.
Pier Block: A concrete block used to support foundation members such
as posts, beams, girders and joist.
Pilaster: A shallow pier or a rectangular column projecting only slightly
from a wall. Primarily decorative but may be structural.
Pilot Light: A small, continuous flame (in a hot water heater, boiler,
or furnace) that ignites gas or oil burners when needed.
Plastic Roof Cement: Used as a waterproofing medium in new construction
and as a general-purpose exterior repair and maintenance material. Stops roof
and other leaks fast. Available in both summer and winter grades.
Plate: 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.
Plenum (or Plenum Chamber): Chamber or container for moving air under
a slight positive pressure to which one or more ducts are connected.
Plumb: Exactly perpendicular; vertical.
Plumb Bob: A lead weight attached to a string. It is the tool used in
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.
Polyethylene Vapor Barrier: Plastic film used to prevent moisture from
passing through unfaced insulation. Both 4- and 6-mil polyethylene are preferred
because they are less likely to be damaged during construction.
Polyurethane Sealant: An organic compound formed by reaction of a glycol
with an isocyanate. A common exterior caulking.
Ponding: A condition where water stands on a roof for prolonged periods
due to poor drainage and/or deflection of the deck.
Porch: The roofed entrance to a house.
Post-and-Beam: A basic building method that uses just a few hefty posts
and beams to support an entire structure. Contrasts with stud framing.
Potable: Water that is safe to drink.
Pressure Tank: Used in conjunction with wells to maintain pressure.
Pressure-Reducing Valve: Valve installed in the water service line where
it enters the building to reduce the pressure of water in the line to an acceptable
pressure used in buildings.
Pressure-Relief Valve: Valve to relieve excess pressure in water storage
Pressure-Treated Lumber: Lumber that is treated in such a way that the
sealer is forced into the pores of the wood.
Primer: A material of relatively thin consistency applied to a surface
for the purpose of creating a more secure bonding surface and to form a barrier
to prevent migration of components. 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.
Purlins: A horizontal structural member spanning between beams or trusses
to support a roof deck. In slope glazing, purlins are the horizontal framing
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.
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Quarry Tile: A man-made or machine-made clay tile used to finish a floor
or wall. Generally 6"X6"X1/4" thick .
Quarter Round: A small molding that has the cross section of a quarter
Quoins: The dressed stones at the corners of buildings, usually laid
so their faces are alternately large and small. Usually in contrasting color
of brick from the rest of the wall. Common accent in Georgian homes.
R-Value: Measure of resistance to heat flow. Insulation materials have
tiny pockets of trapped air. These pockets resist the transfer of heat through
material. The ability of insulation to slow the transfer of heat is measured
in R-values. The higher the R-value, the better the insulation material's ability
to resist the flow of heat through it. It only deals with conduction, one of
three modes of heat flow, (the other two being convection and radiation).
Rabbet: A rectangular, longitudinal groove cut in the corner edge of
a board or plank.
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
Radiation: Any heated surface loses heat to cooler surrounding space
or surfaces through radiation. The earth receives its heat from the sun by radiation.
The heat rays are turned into heat as they strike an object which will absorb
some or all of the heat transmitted.
Radiator: A heating unit which is supplied heat through a hot water
Radon: A naturally-occurring, radioactive gas which is heavier than
air and is common in many parts of the country. Radon gas exposure is associated
with lung cancer. Mitigation measures may involve crawl space and basement venting
and various forms of vapor barriers.
Rafter: A sloping roof member that supports the roof covering which
extends from the ridge or the hip of the roof to the eaves. A common rafter
is one which runs square with the plate and extends to the ridge. A hip rafter
extends from the outside angle of the plate towards the apex of the roof. They
are 2" deeper or wider than common rafters. A valley rafter extends from
an inside angle of the plates toward the ridge of the house.
Rafter Tail: The portion of a rafter that extends past the building
to form the eaves.
Rafter, Hip: A rafter that forms the intersection of an external roof
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.
Rail: Cross members of panel doors or of a sash. Also the upper and
lower members of a balustrade or staircase extending from one vertical support,
such as a post, to another.
Rake: Refers to the slope of the roof at the end of a gable, where the
outside part of the overhang forms an upside down V
Rancher: A single story, one level home.
Raw Linseed Oil: The crude product processed from flaxseed and usually
without much subsequent treatment.
Receptacle: An electrical outlet. A typical household will have many
120 volt receptacles for plugging in lams and appliances and 240 volt receptacles
for the range, clothes dryer, air conditioners, etc.
Reflective Glass: Glass with a metallic coating to reduce solar heat
Refrigerant: A substance that remains a gas at low temperatures and
pressure and can be used to transfer heat. Freon is an example and is used in
air conditioning systems.
Reglet: A horizontal slot, formed or cut in a parapet or other masonry
wall, into which the top edge of counter-flashing can be inserted and anchored.
In glazing, a reglet is typically a pocket or keyway extruded into the framing
for installing the glazing gaskets.
Relative Humidity: A measure of the amount of moisture in the air with
respect to the temperature. It is the ratio of the moisture present to the maximum
amount of moisture the air can hold at that temperature.
Release Tape: A plastic or paper strip that is applied to the back of
self-sealing shingles. This strip prevents the shingles from sticking together
in the bundles, and need not be removed for application.
Remote: Remote electrical, gas, or water meter digital readouts that
are installed near the front of the home in order for utility companies to easily
read the home owners usage of the service.
Re-Pointing: The re-grouting of defective mortar joints in a masonry
or brick wall.
Resilient Flooring: A durable floor cover that has the ability to resume
its original shape.
Resilient Channels: Metal channels used to further inhibit sound transmission
through wall and ceiling framing. Create a break in the vibration path from
drywall to the framing.
Retaining Wall: A structure that holds back a slope and prevents erosion.
Return: In heating and cooling systems, a vent that returns cold air
to be warmed. In a hot air furnace system, it is located near an inside wall.
Ridge: The horizontal line at the junction of the top edges of two sloping
Ridge Board: The board placed on edge at the ridge of the roof into
which the upper ends of the rafters are fastened.
Ridge Vents: A vent mounted along the entire ridge line of the roof
to allow the passage of air through the attic or cathedral ceiling.
Rigid Metal Conduit: This conduit resembles plumbing pipe, protecting
wires from damage.
Rim Joist: Vertical member that forms the perimeter of a floor system
in which the floor joists tie in.
Rise: In stairs, the vertical height of a step or flight of stairs.
Riser: Each of the vertical boards closing the spaces between the treads
Roll Roofing: Roofing material, composed of fiber and satin rated with
asphalt, that is supplied in 36-inch wide rolls with 108 square feet of material.
Weights are generally 45 to 90 pounds per roll.
Rough Opening: The opening in a wall into which a door or window is
to be installed.
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Sash: A single light frame containing one or more lights of glass.
Scratch Coat: The first coat of plaster, which is scratched to form
a bond for the second coat.
Scupper: An outlet in the wall of a building or a parapet wall for drainage
of water from a flat roof.
Semigloss (Paint or Enamel): A paint or enamel made with a slight insufficiency
of nonvolatile vehicle so that its coating, when dry, has some luster but is
not very glossy.
Service Drop: In electrical contracting, the overhead service conductors
from the last pole or other aerial support to and including the splices, if
any, connecting to the service entrance conductors at the building.
Settlement: Shifts in a structure, usually caused by freeze-thaw cycles
Sewage Ejector: A pump used to 'lift' waste water to a gravity sanitary
sewer line. Usually used in basements and other locations which are situated
bellow the level of the side sewer.
Shake: A thick handsplit shingle, resawed to form two shakes; usually
Sheathing: The structural covering, usually wood boards, plywood, gypsum
or wood fiber, used over studs or rafters of framed buildings as the first layer
of outer wall covering nailed to the studs or rafters.
Sheathing Paper: A building material, generally paper or felt, used
in wall and roof construction as a protection against the passage of air and
Shed Roof: A roof having only one slope or pitch, with only one set
of rafters which fall from a higher to a lower wall. A shed is actually a half
gable. One slopping plane is supported by walls. This usually comes off the
back side or out of another roof. Shed roofs are also used over some porches.
Shingles: Roof covering of asphalt, wood, tile, slate, or other material
cut to stock lengths, widths, and thicknesses, which are laid in a series of
overlapping rows as a roof covering on pitched roofs.
Shiplap Lumber: Lumber that is edge-dressed to make a close rabbeted
or lapped joint.
Short Circuit: A situation that occurs when hot and neutral wires come
in contact with each other. Fuses and circuit breakers protect against fire
that could result from a short.
Shutoff Valve: The valve that allows water supply to be cut off to one
fixture without affecting the water supply to the entire house or building.
Common for use with clawfoot tubs, sinks, and toilets.
Shutter: Usually lightweight louvered or flush wood or nonwood 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
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.
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 in a door sill, window sill,
Sill Plate: The framing member anchored to the foundation wall upon
which studs and other framing members will be attached. It is the bottom plate
of exterior walls.
Sill Sealer: A material placed between the top of the foundation wall
and the sill plate. Usually a foam strip, the sill sealer helps make a better
fit and eliminate water problems.
Single Hung Windows: Only the bottom sash moves up and down, the top
Skylight: A structure on a roof that is designed to admit light and
is somewhat above the plane of the roof surface. Sizes, shapes and placement
Slab on Grade: A type of construction in which footings are needed but
little or no foundation wall is poured.
Slate: A dark gray stratified stone cut relatively thin and installed
on pitched roofs in a shingle like fashion.
Sliders: Windows that slide open, like sliding glass doors.
Slope: Incline or pitch of roof surface.
Soffit: The underside of an overhanging cornice of a building extending
out from the plane of the building walls. The wood or metal screening used to
cover such areas.
Solarium: A glass-enclosed porch or room, often used to display flowers
and other plants; also called a sunroom or garden room.
Solid Bridging: A solid member placed between adjacent floor joists
near the center of the span to prevent joists from twisting.
Sonotube: Round, large cardboard tubes designed to hold wet concrete
in place until it hardens.
Spalling: The chipping or flaking of concrete, bricks, or other masonry
where improper drainage or venting and freeze/thaw cycling exists.
Span: The horizontal distance between structural supports such as walls,
columns, piers, beams, girders, and trusses.
Splash Block: A small masonry block laid with the top close to the ground
surface to receive roof drainage from downspouts and to carry it away from the
Square: A unit of measure, e.g. 100 square feet, usually applied to
roofing material. Sidewall coverings are sometimes packed to cover 100 square
feet and are sold on that basis.
Square Foot: Coverage measured by multiplying width by length. An area
5 foot long and 7 foot wide is equal to 35 square feet.
Stain: A form of oil paint, very thin in consistency, intended for coloring
wood with rough surfaces, such as shingles, without forming a coating of significant
thickness or gloss.
Standing Seam: A type of joint often used on metal roofs.
Step Flashing: Individual small pieces of metal flashing material used
to flash around chimneys, dormers, and such projections along the slope of a
roof. The individual pieces are overlapped and stepped up the vertical surface.
Stick Built: A house built without prefabricated parts.
Stile: An upright framing member in a panel door.
Stool: A flat molding fitted over the window sill between jambs and
contacting the bottom rail of the lower sash.
Storm Window: A glazed panel or sash placed on the inside or outside
of an existing sash or window as additional protection against the elements.
Stricker Plate: The metal latch plate in a door frame into which a doorknob
Stringer: In stairs, the support on which the stair treads rest.
String Line: A nylon line usually strung tightly between supports to
indicate both direction and elevation, used in checking grades or deviations
in slopes or rises. Used in landscaping to level the ground.
Stucco: A type of exterior finish. Most commonly refers to an outside
plaster made with Portland cement as its base. A sturdy type of plaster used
on exterior walls, often spread in a decorative pattern.
Stud: A vertical framing member used in both exterior and interior walls.
One of a series of wood or metal vertical structural members placed as supporting
elements in walls and partitions.
Subfloor: The structural material (boards or plywood) that spans across
floor joists. It serves as a working platform during construction and provides
a base for the finish floor.
Sump: Pit or large plastic bucket/barrel inside the home designed to
collect ground water from a perimeter drain system.
Sump Pump: A submersible pump in a sump pit that pumps any excess ground
water to the outside of the home.
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Tailpiece: The tubular part of a lavatory drain that runs from the drain
flange to the trap.
Taping: Applying joint tape over embedding compound in the process of
joint treatment of drywall.
Tempered: Strengthened. Tempered glass will not shatter nor create shards,
but will "pelletize" like an automobile window. Required in tub and
shower enclosures, entry door glass, sidelight glass and in windows where the
window sill is less than 16" to the floor.
Termite Shield: A shield, usually of non-corrodible metal, placed in
or on a foundation wall or other mass of masonry or around pipes to prevent
passage of termites.
Termites: Insects that superficially resemble ants in size, general
appearance, and habit of living in colonies; hence, they are frequently called
"white ants." Subterranean termites establish themselves in buildings
not by being carried in with lumber, but by entering from ground nests after
the building has been constructed. If unmolested, they eat the woodwork, leaving
a shell of sound wood to conceal their activities, and damage may proceed so
far as to cause collapse of parts of a structure before discovery. There are
about 56 species of termites known but the two major ones, classified by the
manner in which they attack wood, are ground inhabiting or subterranean termites
(the most common) and dry wood termites.
Terracotta: A ceramic material molded into masonry units. Fired but
unglazed clay, used mainly for floor and roof tiles. Can be fired in molds to
produce a wide range of shapes. Usually red.
Terrace: A level promenade in front of a building; usually made of stone
and accented with plants, statuary, etc.
Terrazzo: A sturdy flooring finish of marble chips mixed with cement
mortar. After drying, the surface is ground and polished.
Texture Paint: Paint which may be manipulated by brush, trowel or other
to give various patterns.
Thermostat: A device which relegates the temperature of a room or building
by switching heating or cooling equipment on or off.
Thermostatic Valve: A mixing valve that automatically maintains the
temperature setting by regulating fluctuations in water temperature at the water
inlets and immediately adjusting the ratio of hot and cold water that is discharged
by the valve.
Thermal Windows: Windows designed with multiple panes to trap air and
provide greater insulation.
Threshold: A strip of wood or metal with beveled edges used over the
finish floor and the sill of exterior doors.
Thru-Wall Flashing: Flashing extended completely through a masonry wall.
Designed and applied in combination with counter-flashings, to prevent water
which may enter the wall above from proceeding downward in the wall or into
the roof deck or roofing system.
Tip Up: The downspout extension that directs water (from the home's
gutter system) away from the home. They typically swing up when mowing the lawn,
TJI or TJ: Manufactured structural building component resembling the
letter "I." Used as floor joists and rafters. I-joists include two
key parts: flanges and webs. The flange may be made of laminated veneer lumber
or dimensional lumber, usually formed into a 1½" width. The web
is commonly made of plywood or oriented strand board (OSB). Large holes can
be cut in the web to accommodate duct work and plumbing waste lines. I-joists
are available in lengths up to 60'' long.
Tongue and Groove: A type of flooring where the tongue of one board
is joined to the groove of another board.
Tooling: The operation of pressing in and striking a sealant in a joint
to press the sealant against the sides of a joint and secure good adhesion;
the finishing off of the surface of a sealant in a joint so that it is flush
with the surface.
Top Chord: The upper or top member of a truss.
Top Plate: Top horizontal member of a frame wall.
Torch Down Roof (Single Ply or Modified Bitumen): A newer roofing material
mostly used on flat roofs. This material usually comes in rolls and is applied
to the roof with an open flame or 'torch.'
Transit: A surveyors instrument used by builders to establish
points and elevations both vertically and horizontally. It can be used to line
up stakes or to plumb walls or to measure the angle of elevation from a horizontal
Transmitter (Garage Door): The small push-button device that causes
the garage door to open or close.
Transom: Small, usually rectangular or fanlight window over a door.
Some transoms open to cross-ventilate a home, while others are only decorative.
Trap: A plumbing fitting that holds water to prevent air, gas, and vermin
from backing up into a fixture.
Tread: The horizontal board in a stairway on which the foot is placed.
Treated Lumber: A wood product which has been impregnated with chemicals
to reduce damage from wood rot or insects. Often used for the portions of a
structure which is likely to be in ongoing contact with soil and water. Wood
may also be treated with a fire retardant.
Trim: The finish materials in a building, such as moldings applied around
openings (window trim, door trim) or at the floor and ceiling of rooms (baseboard,
cornice, and other moldings). Also, the physical work of installing interior
doors and interior woodwork, to include all handrails, guardrails, stairway
balustrades, mantles, light boxes, base, door casings, cabinets, countertops,
shelves, window sills and aprons, etc. The framing or edging of openings and
other features on the facade of a building or indoors. Trim is usually a different
color or material than the adjacent wall.
Trimmer: A beam or joist to which a header is nailed in framing for
a chimney, stairway, or other opening.
Triple-Glazed Window: The most energy efficient window. Gases are sealed
between three panes of glass and Low E coatings are applied on two of the panes.
This can bring the energy efficiency up to a value of R10 at the center point
of the glass.
Truss: A frame or jointed structure designed to act as a beam of long
span, while each member is usually subjected to longitudinal stress onlyeither
tension or compression.
Tube and Knob Wiring: A common form of electrical wiring used before
World War II. When in good condition it may still be functional for low amperage
use such as smaller light fixture.
Turpentine: A volatile oil used as a thinner in paints and as a solvent
in varnishes. Chemically, it is a mixture of terpenes.
Turret: A very small, slender tower. In modern homes, usually only ornamental.
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U.L. (Underwriters Laboratories): A private research firm located in
the United States that attempts to classify and determine the safety of various
materials and products.
Ultraviolet: The invisible rays of the spectrum of light which are at
its violet end. Sometimes abbreviated U.V.
Undercounter: A style of lavatory which is positioned under the cutout
of the countertop.
Vacuum Breaker: An anti-siphon device that prevents waste water from
being drawn back into supply lines, potentially contaminating the water supply.
A type of backflow preventer.
Valley: The internal angle formed by the junction of two sloping sides
of a roof.
Valve: A device to stop, start or regulate the flow of liquid or gas
through or from piping.
Vapor: The gaseous form of any substance.
Vapor Retarder: Helps control the amount of moisture passing through
the insulation and collecting inside exterior walls, ceilings and floors.
Vapor Impermeable: Materials with a permeance of 0.1 perm or less (rubber
membranes, polyethylene film, glass, aluminum foil)
Vapor Permeable: Materials with a permeance of greater than 10 perms
(housewraps, building papers)
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.
Veneer: Thin sheets of wood made by rotary cutting or slicing a log.
Vent: A pipe or duct which allows flow of air as an inlet or outlet.
Ventilation: Creates a positive flow of air that allows the house to
"breathe" and helps prevent moisture build-up year-round.
Vent System: In plumbing, a system to provide a flow of air to or from
a drainage system or to provide circulation of air within such system to protect
traps seals from siphonage and back pressure.
Venting: The process of installing roof vents in a roof assembly to
relieve vapor pressure. The process of water in the insulation course of the
roof assembly evaporating and exiting via the roof vents.
Visqueen: A 4 mil or 6 mil plastic sheeting.
Vitreous China: A non-porous ceramic that is coated with a ceramic glaze
to form toilets and lavatories.
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Voltage: The driving force behind the flow of electricity somewhat like
pressure is in a water pipe. Most homes are wired with '110' and '220' volt
lines. The '110' volt power is used for lighting and most of the other circuits.
The '220' volt power is usually used for the kitchen stove, water heater and
Walk-Through: A final inspection of a home before "closing"
to look for and document problems that need to be corrected.
Wainscoting: Decorative paneling covering the lower 3-4 feet of an interior
wall. Usually wood in a plain design; may be painted or only varnished.
Waste and Overflow: A bathtub drain assembly that has an outlet at the
top to remove overflow water when filling the tub and an outlet at the bottom
to remove waste water when the tub is drained.
Water Board: Water resistant drywall to be used in tub and shower locations.
Normally green or blue colored.
Water Closet: Toilet.
Waterproofing: The process where a building component is made totally
resistant to the passage of water and/or water vapor.
Water Vapor: Moisture existing as a gas in air.
Water Vapor Retarder: A material or system that adequately impedes the
transmission of water vapor under specified conditions.
Wattage: The electrical unit of power. A kilowatt is 1000 watts and
electric customers are billed on how many kilowatts of power they have used.
Weatherstrip: Jamb-width or narrower sections of thin metal or other
material to prevent infiltration of air and moisture around windows and doors.
Compression weather stripping prevents air infiltration, provides tension, and
acts as a counter balance.
Weep Hole: A hole which allows for drainage of entrapped water from
masonry or glazing structures.
Well Casing: A steel or plastic pipe which serves as the lining of a
well, preventing it from caving in and protecting ground water from contamination
by surface water.
Widow's Walk: A small, railed observation platform atop a house. Once
used to scout for seamen, such walks are usually square, done in elaborately-worked
wrought iron or wood.
Window Frame: The stationary part of a window unit; the window sash
fits into the window frame.
Window Sash: The operating or movable part of a window; the sash is
made of window panes and their border.
Wood Filler: A heavily pigmented preparation used for fining and leveling
off the pores in open-pored woods.
Woven Valley: Method of valley construction in which shingles from both
sides of the valley extend across the valley and are woven together by overlapping
alternate courses as they are applied. The valley flashing is not exposed.
Yard of Concrete: One cubic yard of concrete is 3'x3'x3' in volume,
or 27 cubic feet. One cubic yard of concrete will pour 80 square feet of 3 ½"
sidewalk or basement/garage floor.
Z-bar Flashing: Bent, galvanized metal flashing that's installed above
a horizontal trim board of an exterior window, door, or brick run. It prevents
water from getting behind the trim/brick and into the home.
Zone: The section of a building that is served by one heating or cooling
loop because it has noticeably distinct heating or cooling needs. Also, the
section of property that will be watered from a lawn sprinkler system.
Zone Valve: A device, usually placed near the heater or cooler, which
controls the flow of water or steam to parts of the building; it is controlled
by a zone thermostat.
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