Roofing Terms Starting with A
Explanation of terms used in roofing starting with the letter A.
ACCELERATOR - Any material added to stucco,
plaster, cement, or mortar which speeds up the setting process.
ADHESION Property of a coating or a sealant to bond to the surface of some
ADHESIVE FAILURE Loss of bond of a coating or a sealant.
AGGREGATE - Crushed stone, slag or water-worn gravel that comes in a wide
range of sizes that is used to on built up roofs.
AIR INFILTRATION The amount of air leaking in and out of a building
through cracks in walls, roofs, attics, windows, and doors.
ALLIGATORING - Named for a pattern of cracks resembling an alligator hide. A
condition of paint or aged asphalt brought about by the loss of volatile
oils and the oxidation caused by solar radiation. "Alligatoring" is the
result of the limited ability of paint or asphalt to expansion or
contraction due to temperature changes.
ANCHOR BOLTS - Bolts which fasten columns, girders, supports, or other
members to concrete or masonry, such as bolts used to anchor sills to
ASPHALT - A dark brown to black hydrocarbon product made from the residue
left after the distillation of petroleum. Asphalt is used as a waterproofing
agent in many applications, particularly roofs and highways.
Roofing Terms Starting with B
Explanation of terms used in roofing starting with the letter B.
BACK NAILING - The practice of nailing roofing felts to
the deck under the overlap to prevent slippage of felts.
BARREL ROOF - A roof which in cross section is arched or slightly circular.
BASE PLY - An asphalt saturated or coated roofing felt installed as the
first layer in a built up roof.
BATTEN PLATE - A piece of metal designed to cover the joint between two
lengths of metal edge.
BEAM Structural support member that transfers weight from one location to
BID BOND Bond posted by a bidder to ensure performance.
BIDDING - Getting prices from various contractors and subcontractors.
BID DOCUMENTS Drawings, details, and specifications for a project.
BITUMEN - Any mixtures of hydrocarbons obtained through the distillation of
coal or petroleum. (See also Coat Tar Pitch and Asphalt)
BLISTER - A raised spot on the surface of a building. They are caused by the
expansion of trapped air, water vapor, moisture, or other gases under a
BLUE PRINTS- Architectural plans for a building or construction project,
which are include floor plans, footing and foundation plans, elevations,
plot plans, and other details.
BOND PLASTER - Bond plaster contains 2-5% lime by weight and chemical
additives which improve the bond surfaces such as concrete. It is mostly
used as a base coat.
BRACING - Ties, rods, and other supports used for supporting and
strengthening various parts of a building. Used for lateral stability for
columns and beams.
BRAKE METAL - Sheet metal that has been bent to the certain configuration.
BUILDING BRICK - Brick for building purposes, and formerly called "common
brick." It is stronger than face brick. Not used for cosmetics.
BUILDING PERMIT - Written permits from the city, county or other governing
regulatory body giving permission to construct or renovate a structure.
BUTTERFLY ROOF - A roof that bends downward sharply from either side toward
Roofing Terms Starting with C
Explanation of terms used in roofing starting with the letter C.
CALCIUM CHLORIDE - A chemical used to speed up curing of
CANOPY - An overhanging roof.
CANTILEVER - A projecting beam, piece of lumber, or other structure
supported only at one end.
CANT STRIP - A beveled support used at the intersection of the roof deck
with vertical surfaces so that bends in the roofing membrane to form base
CAP SHEETS One to four layers of felt bonded and coated on the top with
bitumen that is laid over an existing roof. Its purpose is to serve as a
treatment for defective roofs.
CAULK (verb) The application of sealant to a joint, crack or crevice.
(noun) A compound used for sealing. Sometimes it is called low performance
CHECKING - A pattern of surface cracks running in irregular lines. Checking
is the preliminary stage of alligatoring.
COAL TAR PITCH, also called Tar - A bituminous material which is a by
product of coal processing. It is used as the waterproofing material for tar
roofs and gravel roof.
COATING - A layer of liquid product spread over a surface for protection.
COHESIVE FAILURE - Internal splitting of a compound.
COLD APPLIED - Products that can be applied without any heating. These are
in contrast to products which need to be heated during installation.
COLD PATCH In roofing, a roof repair done with Cold Applied material.
COLLAR - In roofing, a metal cap flashing used in conjunction with vents,
pipes, or stacks. Usually the collar is located several inches above the
plane of the roof in order to shedding water away from the base of the vent,
pipe, or stack.
COLLAR BEAM In carpentry, a tie that keeps the roof from spreading. Inside
the attic, it connects similar rafters on opposite sides of roof.
COMPATIBLE - Two or more substances which can be mixed, combined, or blended
without separating, reacting, or affecting either material adversely.
COMPONENT - Any one part of an assembly associated with construction.
COMPOUND - A chemical formulation of ingredients used to produce a caulking,
elastomeric joint sealant, etc.
COMPRESSION GASKET - A gasket designed to function and seal when under
COMPRESSION SET - The permanent deformation of a material after removal of
the stress that performed or caused the compression.
CONDENSATION - The appearance of moisture or water vapor caused by warm,
moist air coming into contact with a colder object.
CONDUCTOR In the roofing industry, a pipe for conveying rain water from
the roof gutter to a drain, or from a roof drain to the drain. It is also
called a Leader, Downspout, or Down pipe.
CONSTRUCTION LOAN - A loan provided specifically to construct or renovate a
CONTROL JOINT - A control joint controls or accommodates movement in the
surface components of a roof.
COOLING TOWER - A large device mounted on roofs with of many surfaces or
baffles over which water is pumped in order to transfer heat and thus cool a
CORNICE - A horizontal projecting course on the exterior of a building,
usually at the base of the parapet.
CORROSION - The deterioration of metal by chemical or electrochemical
reaction resulting from exposure to weathering, sun, moisture, chemicals or
CORRUGATED - Folded or shaped into parallel ridges or furrows.
COST BREAKDOWN - A breakdowns of all projected costs on a construction or
COVENANTS - Rules regarding the physical appearance of buildings in a
particular geographic area. Typical covenants address building height,
appropriate fencing and landscaping, and the type of exterior material, such
stucco, brick, stone, or siding.
CRAWL SPACE - An open area between the floor of a building and the ceiling
CRAZING - A series of hairline cracks in the surface of weathered materials,
having a web-like appearance.
CUPOLA - A small dome at the peak of a roof.
CURB - A short wall or masonry built above the level of the roof that
provides a means of flashing the deck equipment.
CURING AGENT One part of a multi part sealant which, when added to the
base, will cause the base to change its physical state.
CUTBACK In roofing, basic asphalt or tar which has been "cut back" or
diluted with solvents or oils so that the material become more fluid and
easier to work with.
CUT OFF - A piece of roofing membrane consisting of one or more narrow plies
of felt usually applied hot in order to seal the edge of insulation at the
end of a day's work.
Roofing Terms Starting with D
Explanation of terms used in roofing starting with the letter D.
DAMPPROOF - A process used in construction to repel water.
The purpose of damp proofing is to prevent the coated surface from absorbing
rain water while still permitting moisture vapor to escape. Moisture vapor
can easily penetrates coatings of this type.
DEAD LOAD - The constant, design weight of the roof and permanent fixtures
attached above the roof or below the roof
DECK - An elevated platform.
DEFLECT - To bend or deform. This typically happens under the stress of
DEFLECTION The amount of bending of any part of a structural member under
an applied load.
DESIGN PRESSURE Specified pressure a product is designed to withstand.
DORMER - The small house shaped structure which is placed from a sloping
DOUBLE PLATE - When two layers of 2x4's are placed on top of studs in
framing a wall.
DOUBLE TEE - Refers to a precast roof deck panel poured with two fins
underneath its underside to impart strength and rigidity.
DOWNSPOUT - The pipe used to drain water from a roof.
DRAWING OUTLINE - A top view drawing of a building or roof showing only the
DRAWING DETAIL - A top view drawing of a building or roof showing the roof
perimeter and indicating the projections and roof mounted equipment.
DRIP EDGE - A device designed to prevent water from running back or under an
DRIPPAGE - Bitumen material that drips through roof deck joints, or over the
edge of a roof deck.
DRY IN - To make a home, house, structure, or building waterproof.
DRY SHEET - A ply or layer of material mechanically attached to wood or
gypsum decks to prevent asphalt or pitch from penetrating the deck and
leaking into the building below.
DUCT - A cylindrical or rectangular "tube" used to move air inside a
building. The installation is referred to as "duct work".
DUROMETER The measurement of hardness of a material. A gauge to measure
the hardness of an elastomeric material
Roofing Terms Starting with E
Explanation of terms used in roofing starting with the letter E.
EPDM - also called Ethylene Propylene Diene Monomer. A
single ply membrane consisting of synthetic rubber.
EAVE - The part of a roof which projects out from the side wall, or the
lower edge of the part of a roof that overhangs a wall.
EDGE METAL - A term for metal around the perimeter of a roof.
EER - Energy Efficiency Ratio - The ratio figured by dividing BTU hours by
EFFLORESCENCE - When water leeches soluble salts out of concrete or mortar
and deposits them on the surface. Also used as the name for these deposits.
EIFS Exterior Insulating Finish System - Exterior wall cladding system
made up of polystyrene foam board with a textured acrylic finish that
resembles plaster or stucco.
ELASTOMER An elastic, rubber like substance, such as natural or synthetic
ELASTOMERIC Any of the numerous flexible films or membranes that contain
rubber or plastic.
ELEVATION - A side of a building.
EMISSIVITY The measurement of a surfaces ability to emit long wave
EMULSION - A coating consisting of asphalt and fillers suspended in water.
END DAMS Internal flashing or dam that prevents water from moving
laterally within a wall.
END LAP - The amount of overlap at the end of a roll of roofing felts.
EXPANSION COEFFICIENT - The amount that a material will expand or contract
with a change of temperature.
EXPANSION JOINT - A device that allows a structure to expand or contract
EXTRUSION - An item formed by forcing a metal, usually aluminum, or a
plastic, through a die to achieve a specific shape.
EYEBROW - A projection which sticks out horizontally from a building wall,
typically above a window.
Roofing Terms Starting with F
Explanation of terms used in roofing starting with the letter F.
FACADE - The front of a building.
FACE BRICK - Brick made especially for exterior use, mindful of color,
texture and size, and used as a facing on a building.
FACTORY MUTUAL or FM - Major insurance agency who has established stringent
guidelines for maximum construction integrity as it relates to fire and
environmental hazards. Their specifications have become industry standards.
FASCIA - Cover board or metal at edges or eaves of a roof which is placed in
a position vertically to protect the edge of the roof.
FASTENERS - A general term covering screws and nails which are used for
mechanically securing building material.
FELT - A very general term used to describe composition of roofing ply
sheets, consisting impregnated with asphalt or coal tar pitch.
FENESTRATION Any glass, window, door, curtain wall, or skylight on the
exterior of a building.
FERROUS - Refers to objects made iron, such as ferrous pipe.
FILLET BEAD Caulking or sealant placed in such a manner that it forms an
angle between the materials being caulked.
FINISH COAT The last coat applied in plastering intended as a base for
further decorating or as a final decorative surface.
FIRE-RATED Descriptive of materials that has been tested for use in fire
FIRE WALL - Any wall built for the purpose of preventing the spread of fire.
Such walls of solid masonry or concrete generally divide a building starting
at the foundations and going to two or more feet above the top of the roof.
FLASHING - Weatherproof material installed between roof sheathing or wall
sheathing and the finish materials to help keep moisture away from the
FLASHING BASE - The upturned edge of the watertight membrane formed at a
roof termination point.
FLASHING, COUNTER - The formed metal secured to a wall or roof top to cover
and protect the upper edge of a base flashing.
FLASHING, STEP - Individual pieces of metal flashing material used to flash
around chimneys, dormers, and such projections along the slope of a roof.
FLASH POINT - The critical temperature at which a material will ignite and
FLASHING, THRU-WALL - Flashing extended completely through a masonry wall.
FULLY ADHERED - A completely attached and adhered roof membrane.
Roofing Terms Starting with G
Explanation of terms used in roofing starting with the letter G.
GABLE - The ends of a home, house, residence, structure,
or building as different from the front or rear side. Also the triangular
end of an exterior wall from the level of the eaves to the top of a double
GAMBREL ROOF - A type of roof which has two slopes so that the lower slope
is steeper than the upper slope. A double sloped roof having two pitches.
This typically enables the rooms underneath to be larger than with a single
GALVANIZE - To coat a metal with zinc. This makes the material longer
lasting and more weather resistant.
GASKETS Pre-formed shapes of rubber or rubber-like material, used to fill
and seal a joint or opening.
GAUGE - The thickness of sheet metal and wire.
GENERAL CONTRACTOR - A contractor or builder responsible for all facets of
construction of a building or renovation.
GFI, GFCI, Ground Fault Circuit Interrupters - Special devices capable of
opening a electrical circuit when even a small amount of electricity is
flowing through. Used to prevent electrocutions and fires. Typically these
are used anywhere outlets, wiring, or lighting fixtures in a home are near
or could be exposed to water, such as in the kitchen, bathrooms, garage,
outside outlets, or for swimming pool lights, as examples.
GFRC, Glass Fiber Reinforced Concrete Concrete with embedded glass fibers.
Used in wall systems. Resembles concrete but does not perform as well as
concrete. Usually a thin cement material put on plywood or other lightweight
GIRDER - A main beam upon which floor joists rest, usually made of steel or
GLAZE COAT In roofing, a light, uniform mopping of bitumen or asphalt
applied to roofing felt to protect the felt from the rain, snow, sun and
other weather conditions.
GLAZING A generic term used to describe material such as glass, panels,
etc. that is used to fill in openings. (v) The process of installing a
material to fill in openings in windows, door panels, etc.
GLAZING BEAD In glazing, a strip surrounding the edge of the glass in a
window or a door which holds the glass in place.
GLAZING CHANNEL In glazing, a three-sided, U-shaped sash cut into which a
glass product is installed and retained.
GRADE MW - Moderate Weather grade of brick for moderate resistance to
freezing used, for example, in planters or in outside non structural
GRADE NW - No Weather grade of brick intended for use as a backup or in
GRADE SW - Severe Weather grade of brick intended for use where high
resistance to freezing is desired.
GRANULES - The mineral particles which are embedded in the coating of
shingles & roofing.
GRAVEL - Loose fragments of rock used for surfacing built-up roofs.
GROUND SYSTEM - The connection of a wire to the grounding terminal in the
main switch which in turn is connected to a water pipe. The neutral wire is
called the ground wire.
GROUNDING ROD A rod used to ground an electrical panel.
GROUT OR GROUTING - A cement/mortar mixture commonly used to fill joints and
holes or openings in masonry, tile, or similar work.
GAUGE BOARD, also known as Spot Board A board used by workers to carry
grout while it is being applied.
GUN CONSISTENCY The degree of viscosity needed for application through the
nozzle of a caulking gun.
GUNITE - A construction material composed of cement, sand, and water mixed
together. It is applied with a cement gun, and is used in the construction
of swimming pools.
GUTTER - Metal channel or trough at the edges or eaves of a roof to carry
rain water from the roof to the downspout.
GUTTER STRAP - Metal bands used to support the gutter.
GUY WIRE - A strong steel wire or cable strung from an anchor on the roof to
any tall slender projection for the purpose of support. For example, used to
hold a slender antenna in place.