Roofing Terms and Glossary
Battens and counter-battens
Strips of wood or metal attached to a steep-slope roof deck. Roofing such as metal panels and clay or concrete tiles are then attached to the battens. The purpose is to allow airflow between the deck and roofing for dispersing moisture and heat. Battens run horizontally from the eave to the peak. Counter-battens run laterally between battens.
Boot
A flexible covering shaped to surround a roof penetration such as a vent stack and extend beneath the surrounding roofing material. A boot is used to keep out moisture and debris.
Cap Sheet
The top ply of multi-layered roofing. It is often covered with mineral or ceramic granules.
Coating
Liquid sprayed or brushed onto a roof surface or roofing material to provide weather protection and/or color.
Cold-applied
Liquid roofing material or coating that can be applied without heating, compared with materials that must be heated and hot-applied.
Cool roof
Roofing material with high reflectivity and emissivity to maintain the roof at a much lower temperature than standard materials. Some cool roofing meets Energy Star criteria and Cool Roof Rating Council certifications.
Cricket or cricket saddle
A small, built-up area of roof installed where a steep slope meets a projection such as a wall or chimney. The purpose is to divert water away from the projection.
Curb
A raised frame built to support a skylight, hatch or equipment and to keep it higher than water flowing or accumulating on the roof.
Deck
The roof deck is the material that is fastened to the roof trusses. Common materials are OSB and plywood in residential construction and corrugated metal in commercial construction. The deck is the substrate for the roofing material such as underlayment or roofing paper and asphalt shingles
Dormer
A framed structure with walls that projects from sloped roofing. Dormers may extend from the attic or living space.
Drip edge
A strip of metal installed on a roof eave that directs water beyond the fascia to drip into a gutter or onto the ground.
Eave
The low edge of a sloped roof. The eave might be flush with or extend beyond the wall beneath.
Fascia
The vertical or steeply sloped trim board fixed to the truss or rafter tails. Gutters are attached to the fascia.
Flashing
Material, usually metal, used as a moisture barrier at susceptible points such as where a roof meets a chimney, wall or other projection or penetration. Step flashing, membrane base flashing and cap flashing are common types.
Gable
The section of wall, usually a triangle, beneath the peak of a sloped roof.
Hip
The line where two sections of sloped roof meet. The fascia of the sections join at a right angle.
Read our comparison post to learn the difference between a gable or hip roof.
Membrane
A flexible sheet of waterproof roof covering. The membrane might be installed as a base, middle or top layer.
Ponding
Water remaining in low areas of flat roofs for more than 2 days when weather conditions are suitable to drying. Ponding can cause deterioration of roofing materials.
Rake
The outside edge of a sloped roof. The rake runs from the eave to the ridge.
Ridge
The horizontal line where two sloped sections of roof meet, forming the high point of the structure.
Ridge cap
Roofing material such as shingles or roll roofing that covers the gap at the ridge of a roof.
Ridge vent
Vent installed along the ridge to allow venting of heat and moisture from the attic or cavity between trusses. Ridge cap is installed so that it does not block the vent.
Roll roofing
Roofing made from felt coated with asphalt or synthetic material. Roll roofing is often covered with granules.
Roof assembly
All the materials used to form the roof including roof trusses, the deck, moisture barrier, roofing materials, vents and drains. Also called a roof system.
Roof slope
The angle of the roof. Slope is often determined by the number of inches a roof rises as it travels one foot toward the ridge. Steep-slope roofing has a slope of 4:12 or higher – four inches of rise for each 12 inches of run. Low-slope roofing is 3:12 and less.
Soffit
The exterior surface beneath an overhanging eave.
Standing seam
Seams where metal roof panels are joined. The seam is raised, or standing, to lift it above the flow of water down a sloped roof.
Starter course
Roofing material, either rolled or individual pieces, installed at the roof eaves and rakes. The starter course serves as additional weather barrier at these susceptible roof perimeters.
Truss
Triangular assemblies of framing members. Installed at intervals of 16 or 24 inches apart, the trusses are the support for sloped roofs.
Valley
The inward angle where two down-sloping roof sections meet. Valleys are lined with moisture barrier before the rest of the roofing material is installed.