Roofing Terminology: A Glossary
The words on a roofing quote, a supply order or a calculator, defined in plain English.
- Bundle
- A package of shingles. Most products are three bundles per square (100 sq ft).
- Cap nail
- A nail with a wide plastic or metal washer, used to hold underlayment without tearing it.
- Cricket (saddle)
- A small peaked structure behind a chimney or curb that diverts water around it.
- Counter-flashing
- Metal set into a wall or chimney that laps over the base or step flashing below it.
- Deck (sheathing)
- The plywood, OSB or plank surface the roofing is fastened to.
- Dormer
- A framed projection through the roof slope, usually with a window.
- Drip edge
- Bent metal at the eaves and rakes that directs water away from the fascia and protects the deck edge.
- Eave
- The lower, horizontal edge of a roof plane, usually where the gutter hangs.
- Exposure
- The part of each shingle or panel left visible after the next course goes on, such as 5 or 5-5/8 inches.
- Fascia
- The board along the ends of the rafters at the eave.
- Flashing
- Metal or membrane that seals joints and transitions, such as walls, valleys, chimneys and vents.
- Gable
- The triangular wall at the end of a ridge roof; a gable roof has two slopes meeting at a ridge.
- Hip
- The sloped external angle where two roof planes meet, running from the ridge down to a corner.
- Hip roof
- A roof that slopes down to the eaves on all sides, with no gable ends.
- Ice barrier (ice and water shield)
- A self-adhering membrane applied at eaves, valleys and penetrations to resist ice dams and wind-driven rain.
- Laminated (architectural) shingle
- A shingle made of two or more bonded layers for a thicker, dimensional look.
- Low-slope roof
- A roof with a pitch under about 3/12 to 4/12, often covered with membranes or metal.
- Pitch
- The rise of a roof in inches per 12 inches of horizontal run, written like 6/12.
- Pitch multiplier
- The factor that converts flat footprint area or horizontal run into sloped area or length.
- Rafter
- A sloped framing member running from the wall plate to the ridge.
- Rake
- The sloped edge of a roof at a gable end.
- Ridge
- The horizontal line at the top of a roof where two planes meet.
- Ridge vent
- A vent installed along the ridge, under cap shingles or metal, to exhaust attic air.
- Run
- The horizontal distance a rafter covers, usually half the building span.
- Soffit
- The underside of the roof overhang; soffit vents bring air into the attic.
- Span
- The horizontal distance between the outside of opposite walls.
- Square
- 100 square feet of roof surface, the basic unit for pricing and ordering roofing.
- Starter strip
- The first course at the eaves (and sometimes rakes), which seals the bottom edge of the first row of shingles.
- Step flashing
- Individual L-shaped pieces woven into each shingle course where a roof meets a wall.
- Tear-off
- Removing the existing roofing down to the deck before installing new roofing.
- Truss
- A prefabricated triangular frame that replaces rafters and ceiling joists.
- Underlayment
- The water-resistant layer (felt or synthetic) between the deck and the roofing.
- Valley
- The internal angle where two roof planes meet and water concentrates.
- Waste factor
- The extra material, as a percentage, ordered to cover cutting and offcuts.
Put the terms to work: find your pitch, measure the area, then run the shingle takeoff.
Frequently asked questions
What is a square in roofing?
A square is 100 square feet of roof surface.
What is the difference between a hip and a valley?
A hip is an outside corner where two roof planes meet and shed water away; a valley is an inside corner where water from two planes collects.
What is the difference between an eave and a rake?
The eave is the lower horizontal edge of the roof; the rake is the sloped edge at a gable end.
Last reviewed 2026-10-10. Results are estimates for planning; confirm quantities with your supplier and requirements with your local building code and the manufacturer's instructions.