Roofing Glossary


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.

Cap flashing– The portion of the flashing attached to a vertical surface to prevent water from migrating behind the base flashing.

Collar- Preformed flange placed over a vent pipe to seal the roofing above the vent pipe opening. Also called a vent sleeve.

Cricket– A second roof built on top of the primary roof to increase the slope of the roof or valley. A saddle-shaped, peaked construction connecting a sloping roof with a chimney. Designed to encourage water drainage away from the chimney joint.

Cripple– Short vertical “2 by 4’s or 6’s” frame lumber installed above a window or door.

Dormer– An opening in a sloping roof, the framing of which projects out to form a vertical wall suitable for windows or other openings.

Downspout– A pipe, usually of metal, for carrying rainwater down from the roof’s horizontal gutters.

Drippage-Bitumen material that drips through roof deck joints, or over the edge of a roof deck.

DWV (drain-waste-vent)- The section of a plumbing system that carries water and sewer gases out of a home.

Eaves-The lower, level part of a roof overhanging a wall.

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.

Elastomer-An elastic rubber-like substance, such as natural or synthetic rubber.

Elastomeric– Of or pertaining to any of the numerous flexible membranes that contain rubber or plastic.

Electrolytic Coupling– A fitting required to join copper to galvanized pipe and gasketed to prevent galvanic action. Connecting pipes of different materials may result in electrolysis.

Elevation– A side of a building.

Emissivity– The measure of a surfaces ability to emit long-wave infrared radiation.

Emulsion– In roofing, a coating consisting of asphalt and fillers suspended in water.

End Dams– Internal flashing (dam) that prevents water from moving laterally within a curtain wall or window wall system.

End Lap– The amount or location of overlap at the end of a roll of roofing felts in the application.

EPDM– Ethylene Propylene Diene Monomer. A single ply membrane consisting of synthetic rubber; usually 45 or 60 mils. Application can be ballasted, fully adhered or mechanically attached.

Elevation- An Elevation is the view of the side of the house or a wall in a room as if the viewer is standing back and looking straight at it. This drawing shows each side of the house including the foundation and roof. It shows the configuration of the windows (sliding, casement, awnings, etc.), the outside doors, handrails, gutters, the pitch and overhang of the roof, the siding, roofing, and any chimneys. Usually the dimensions are left off, but the drawing is to the scale noted. This drawing is used to determine the shape and openings of windows, with bathroom windows noted as obscure, the look of the exterior doors, and the shape of the roof. The height of the house can easily be determined, as well.

Fascia- The trim piece nailed to the ends of a series of rafters or trusses to tie them together at the lower, level end of a roof. The fascia supports the sheathing on the edge of the roof as well as the front edge of the soffit.

Fascia Board- The exterior finish nailed to the fascia that is nailed to the rafter or truss ends that runs horizontally around the roof on which the gutters are mounted. The fascia board forms a drip edge for rain water, as well as hides the end of the roof sheathing and soffits.

Flashing– Weatherproof material installed between roof sheathing (or wall sheathing) and the finish materials to help keep moisture away from the sheathing. Typically, sheet metal or a similar material is used in roof and wall construction to protect a building from water seepage.

Flue– Large pipe through which fumes escape from a gas water heater, furnace, or fireplace. Normally these flue pipes are double walled, galvanized sheet metal pipe and sometimes referred to as a “B Vent”. Fireplace flue pipes are normally triple walled. In addition, nothing combustible shall be within one inch from the flue pipe.

Flue collar Round metal ring which fits around the heat flue pipe after the pipe passes out of the roof.

Flue damper– An automatic door located in the flue that closes it off when the burner turns off; purpose is to reduce heat loss up the flue from the still-warm furnace or boiler.

Flue lining– 2-foot lengths, fire clay or terra-cotta pipe (round or square) and usually madein all ordinary flue sizes. Used for the inner lining of chimneys with the brick or masonry work done around the outside. Flue linings in chimneys runs from one foot below the flue connection to the top of the chimney.

Folded Seam– In sheet metal work, a joint between sheets of metal wherein the edges of the sheets are crimped together and folded flat.

GableHouse framing: The upper triangular-shaped portion of the end wall of a house.
Gable End-The entire end wall of a house formed from the pitch of the roof.

Gable Truss- The end truss in a roof system that caps the end wall. If the overhang is more than 16″, the gable truss is lowered by 3 1/2″ to allow for 2×4’s to be cantilevered over this truss and nailed into the adjoining one to form the overhang.

Glaze Coat– In roofing, a light, uniform mopping of bitumen on exposed felts to protect them from the weather, pending completion of the job.

Gutter– Metal or wood trough at the eaves of a roof to carry rain water from the roof to the downspout. A shallow channel or conduit of metal or wood set below and along the (fascia) eaves of a house to catch and carry off rainwater from the roof.

Gutter Strap– Metal bands used to support the gutter.

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

Hip roof– A roof that rises by inclined planes from all four sides of a building.

Laminated shingles – Shingles that have added dimensionality because of extra layers or tabs, giving a shake-like appearance. May also be called “architectural shingles” or “three-dimensional shingles.”

Liquid-Applied Membrane– Generally applied to cast-in-place concrete surfaces in one or more coats to provide fully-adhered waterproof membranes which conform to all contours.

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.

Mopping– In roofing, a layer of hot bitumen mopped between plies of roofing felt. Full mopping is the application of bitumen by mopping in such a manner that the surface being mopped is entirely coated with a reasonably uniform coating. Spot Mopping is the procedure of applying hot bitumen in a random fashion of small daubs, as compared to full mopping. Sprinkle mopping is a special application of installing insulation to the decks. It is done by dipping a roof mop into hot bitumen and sprinkling the material onto the deck. Strip Mopping is the application of bitumen in parallel bands.

Overhang– Outward projecting eave-soffit area of a roof; the part of the roof that hangs out or over the outside wall. See also Cornice.

Pitch- The angle of the roof slope, measured as “X” inches per 12″ (x/12). Roof pitches commonly range from 4/12 to 8/12. To calculate a roof’s pitch, place a carpenter’s level positioned level on roof line, measure out 12″ on the level, from that 12″ point measure down to the roof line. This figure (i.e. 4″ to 8″) is the first number of the pitch.

Rafter- The slanting boards that give the roof its slope and support. They are like wall studs except they are slanted for the roof.

Rail- The horizontal members of the face frame of a set of cabinets.

Rake- The edge of a sloped roof forming the overhang beyond the wall of a gable roof or other sloped roof.

Run, roof – The horizontal distance from the eaves to a point directly under the ridge. One half the span.

Shake– A wood roofing material, normally cedar or redwood. Produced by splitting a block of the wood along the grain line. Modern shakes are sometimes machine sawn on one side. See shingle.

Sheathing- The structural covering applied over studs, rafters or roof trusses.

SoffitThe underside board of eaves and rakes. Soffits are often vented to draw air into the attic.

Span of a Roof- This is the entire horizontal distance across that a roof covers. This is usually twice the total run for a gable roof. There are factors where this is not the case, such as a shed roof or an unequally pitched gable roof.

Step flashing– Flashing application method used where a vertical surface meets a sloping roof plane. 6″ X 6″ galvanized metal bent at a 90 degree angle, and installed beneath siding and over the top of shingles. Each piece overlaps the one beneath it the entire length of the sloping roof (step by step).

Valley- The inward angle of two sloping roof sections. Framing consists of a doubled valley rafter in the middle that extends from a top plate corner to a second ridge board, with angled jack rafters for support.

Summit General Contracting
Phone: 817-501-8333