BARRIER: material or
surface designed to prevent passage of air, but
not water vapor.
AIR GAP: a
separation between any pipe or faucet conveying
water and the flood-level rim of any plumbing
ampere-carrying capacity of a wire.
unit of electrical current. Often abbreviated
VALVE: valve on a lawn sprinkler that prevents
the sprinkler water from backflowing
main water supply.
fire and heat-resistant material used in
construction until the early 1970s, when it was
discovered to pose health hazards.
opening in the floor of a fireplace for ash
PLASTIC CEMENT: asphalt used to seal roofing
space under the roof of a structure but above
the top floor.
PREVENTER VALVE: see anti-siphon valve
FRAME: wood frame in which studs are continuous
from the sill plate to the top plate of the top
vertical member under a stair, deck, or porch
Any board or molding covering an interior wall
where it meets the floor.
oblong blanket of fiberglass
thin wood molding used to cover a joint (usually
used with siding).
window that projects outward from the
WALL: wall that supports a load from above, such
as a vertical load of a roof system.
substance containing oil or coal-based
compounds; (asphalt based roofing
CIRCUIT: one of several circuits in a building,
originating at the service entrance
panel and protected by a separate circuit
breaker or fuse.
VENEER: brick facing over wood or masonry
bracing between floor joists to prevent twisting
THERMAL UNIT (BTU): amount of heat required to
raise the temperature of 1 pound of water by 1
PAPER: a waterproof heavy paper used in
construction of a roof or wall.
roofing consisting of many alternating
layers of asphalt and felt.
rectangular metal bar (usually copper) for
carrying large electrical current.
joint in which two members meet without overlap
movement of water through small gaps due
to adhesion and surface tension.
WINDOW: window hinged on the side and opening
inside or outside molding.
INSULATION: loose-fill insulation consisting of
shredded and treated newspaper.
cracks in the surface of wood resulting from
drying and shrinking of the surface faster then
PLUG: a threaded fitting in a pipe or fixture
that provides access for cleaning or
two or more wires carrying electricity to
lights, receptacles, switches and appliances.
BREAKER: electromechanical device that opens
when the circuit exceeds its electrical
board used for overlapping as horizontal siding.
VALLEY: roof valley where the shingles extend in
an unbroken line across the valley
BEAM: a horizontal beam fastened above the upper
ends of rafters to stabilize them.
wire intended to carry electrical
metal or plastic pipe that surrounds electrical
wires and protects them from physical
heat transfer through either the natural or
forced movement of air.
to sink a nail or screw below the
a space between the ground and the first floor
of a house that allows access for repair of
utilities that run under the house.
small roof for diverting water away from
the back side of a chimney.
WALL: a short wall built upon the foundation of
a house that produces a high
adjustable plate in the flue of a fireplace or
furnace that is used to control the draft from
water-proofing a masonry surface to retard
capillary action and water leaks.
load imposed on a structure by the weight of the
building materials only.
deterioration of wood from attack by fungi or
air temperature at which water vapor begins to
condense as either water or ice
UNION: type of connector that insulates two
different types of metal pipe to prevent
LUMBER: framing lumber 2 to 5 inches in
thickness and up to 12 inches in nominal
VALVE: valve in a septic tank system that allows
the user to alternate leach lines.
vertical window projecting from a roof; gabled
dormers have peaked roofs, shed dormers have
GLAZING: insulated window pane formed by two
thicknesses of glass with a sealed air space
DOUBLE LUGGING: running two or more electrical circuits
off a single lug (terminal or
pipes leading from the gutters of a roof to the
ground and away from the building.
gradual flowing of liquids off a surface. Any
system to remove liquid waste or rainwater by
channeling its flow to a designated area.
material designed to force water to drip away
from roof rakes and eaves.
conduit for hot air, gas, water, electrical
lower part of a roof that projects beyond an
EGRESS WINDOW: window whose clear dimensions are large
enough that it can serve as a fire
view of a vertical face of a
vertical flat board at the roof eaves, that the
gutters are attached to.
special clay brick that can be exposed to
extremely high temperature change without
damage; used in furnaces, fireplaces and similar
high temperature areas.
framing member designed to block the spread of
fire within a framing cavity.
sheet metal or similar materials used at
different points in a structure to prevent water
seepage, such as around vent pipes
FLOOR FURNACE: a ductless furnace placed
directly below a floor that transmits heat only
through a grille in the floor.
a framing piece that rests on the outer
foundation walls and interior beams or girders,
and supports the flooring above.
opening or passageway in a chimney through which
smoke, gases, etc., pass from a building. Any
opening or passageway for the elimination of
gases or fumes.
foot like projection at the base of a foundation
wall, column, pier, etc., used to secure,
support, and help eliminate settling or shifting
of the wall.
FURNACE: furnace that has a fan or blower which
forces warm air through the ducts.
the part of a building, usually below ground
level, that supports the superstructure above
wood structure of a building that provides its
strength and shape; includes exterior and
interior walls, floor, roof, and
wood construction, the horizontal board between
the top of the siding and the soffit.
HEAVE: expansion of the earth due to freezing of
maximum depth of freezing in the
short plug in an electric panel box that
interrupts an electrical
circuit when it becomes overloaded.
large or principal beam used to support
concentrated loads or weight at particular
points along its length.
glass or other transparent material used for
level of the ground.
WIRE: wire in a circuit that is connected to the
ground and serves to return current from the
hot wire back to the ground.
Identified by a white insulation
FAULT INTERRUPTER: (GFI or GFCI) circuit breaker
that trips on leakage of current.
WIRE: bare or green wire in a circuit that
connects metal components, such as appliance
cabinets, to the ground.
thin mortar applied to masonry
beam over a door or window for supporting the
load from above.
stone or brick floor of a fireplace.
method of distributing heat by hot
steel whose cross section resembles the letter
ridge of ice at roof eaves or gutters causing
snow and ice blockage, and preventing from
Incursion of outdoor air through cracks, holes
GLASS: factory-sealed double or triple
and sides of a door or window.
COMPOUND: material used to finish joints in
gypsum drywall. Known as mud.
BOX (J-box): a device in which wires are spliced
to bring various electrical circuits
WIRING: oldest type of electrical wiring; the
knobs serve as insulators, and the ceramic tubes
isolate the wiring from neighboring
perforated base for application of plaster;
formerly wood, now usually metal.
framework of crossed strips of wood, plastic, or
a gravel-filled subsurface trench extending from
a septic tank; liquid wastes are
absorbed into the leach line's soil
WALL: a wall capable of supporting
solid member above a door or window that carries
the load above.
temporary load imposed on a building by
occupancy and the environment.
construction consisting of stone, brick, or
ROOF: roofing consisting of a single waterproof
cut at an angle other than 90
BARRIER: treated paper or metal that retards or
bars water vapor, used to keep moisture from
passing into walls or floors.
mixture of cement, sand, and water.
WALL: wall or partition that does not carry a
load from above.
projection of a stair tread beyond the
(OC): framing measurement from the center of one
member to the center of the next.
VALLEY: roof valley where shingles do not cross
the valley intersection; flashing
low wall or barrier at the edge of a balcony or
surface coat of cement over masonry to help
SOLAR COLLECTOR: system for collecting solar
energy without use of mechanical devices
such as fans or pumps.
angle of slope of a roof. (i.e. 4 inches rise in
a 12 inch area equals a 4/12 pitch
horizontal framing member at the top or bottom
of a wall.
chamber that can serve as a distribution area
for heating or cooling systems, generally
located between a false ceiling and the actual
the electrical charge, either positive or
negative, of an electric service
WOOD: wood that has been injected with
preservative under pressure.
distortion of a building surface from the
HEATING: method of heating whereby much of the
heat transfer is accomplished by radiation
through space from warm building,
surfaces such as floors, walls, or
roof beam running in the direction of the
steel bars used in concrete, to strengthen it
and tie it together.
HUMIDITY: amount of water vapor in
air compared with the maximum amount possible,
expressed as a percentage.
to upgrade a structure using modem
highest point of a roof.
BOARD: A board running the length of the ridge
of the roof, to which rafters are
continuous, prefabricated outlet ventilator
placed over an opening at the ridge of the roof
line to allow the release of air.
vertical increase in one step of a
vertical board between stair treads. Also a
vertical plumbing pipe.
ROOFING: low-cost asphalt roofing in roll
measurement of a materials resistance to
holding the panes of glass in a window or
compressible material used to seal building
GLASS: panes of glass with a sealed air space
DROP: service entry wiring from the utility pole
to the meter.
layer of boards over the framing but under the
plasterboard compound of a core of gypsum
between two sheets of heavy paper.
tapered piece of wood or metal, used to level
small, thin piece of material, often tapered,
for laying in overlapping rows as in roofing or
lowest horizontal member in a frame. Also the
bottom piece of the window rough
window in a roof or ceiling.
concrete slab resting directly on the ground at
near grade level.
underside of a roof overhang, cornice, or
distance between supports.
ARRESTER: wire mesh device placed atop a chimney
to prevent embers from blowing out onto the
metal roofing technique of folding the upturned
edges of adjacent sheets to form a weatherproof
vertical outside frame member in a door or
interior horizontal, flat molding at the bottom
of a window.
(MOLDING): thin molding for stopping doors on
closure or holding window sash in
side member of stairway into which the stair
treads and risers are attached and
wet plaster finish, specifically designed for
exterior use; popular as an outside wall surface
or as a siding material.
vertical framing member to which wall sheathing
and siding are
first floor laid over the floor joists. The
subfloor may also serve as the finish
exposed portion of an asphalt shingle between
finishing gypsum drywall joints with paper tape
and joint compound.
GLASS: glass that has been cooled rapidly to
produce surface tension; the result is a
stronger-than normal glass that shatters into
relatively harmless cubical fragments when
a wooden or metal strip under an outside door;
the entrance to a building.
protective device installed in a combustible
wall through which a stovepipe
NAILING: nailing a wood joint at an angle for
GROOVE: flooring and sheathing joint in which
the tongue of one piece meets a groove in a
curved section of drain pipes used under
plumbing fixtures to "trap" waste material or
horizontal part of a step.
framing structure for spanning great distances,
in which every member is purely in tension or
sheet material or wood providing a smooth, sound
base for the finished floor above.
VAPOR BARRIER: material or surface designed to block
diffusion of water vapor.
type of insulation.
HAMMER: sound made by supply pipes when water is
suddenly stopped by the quick closing of a