Application Rate: The average quantity of material applied per unit area.

Architectural Panel: A metal roof panel, typically with a standing seam or batten seam that usually requires solid decking.

Architectural Shingle: A composition shingle that provides a dimensional appearance. Also referred to as a Laminated Shingle.

ARMA: Asphalt Roofing Manufacturers Association

Asbestos: A group of natural, fibrous, impure silicate materials used for fireproofing and sometimes used for reinforcement of roofing materials.

Asphalt: A dark brown or black substance left as a residue after evaporating or otherwise processing petroleum. Asphalt can be modified to conform to a variety of roofing grade specifications.

Asphalt Felt: An asphalt impregnated or coated felt usually used as an underlayment beneath shingle application.

Asphalt Roof Cement: An asphalt based cement containing solvent, used to bond roofing materials. Also known as asphalt plastic cement, flashing cement, or mastic.

Asphalt Shingle: A shingle manufactured by coating a reinforcing material (felt or fiberglass mat) with asphalt and applying mineral granules to the exposed side. See Shingle.

ASTM: American Society for Testing and Materials

Back to top


Back-Nailing: A method of installing the back or upper portion of a ply of roofing material so that the fasteners are covered by the following ply. See Blind-Nailing.

Base Flashing: Plies or strips of roof membrane material used to seal a roof at the horizontal to vertical intersections such as at a roof-wall and roof-curb junctures.

Base Ply: The bottom or first ply membrane in a built-up roof system.

Base Sheet: An asphalt impregnated or saturated felt used as the first ply in some low-slope roof systems.

Batten: Strips of wood laid parallel on which roof tiles are installed.

Bird Screen: Wire mesh used to cover vents, louver or other openings, to prevent birds from entering a building.

Bleeder Strips: A starter strip placed along the rake edge of a roof when installing composition roofing. See Rake-Starter.

Blind-Nailing: The method of nailing roofing so the fastener is not exposed to the weather. See Back-Nailing.

Blister: A pocket of air or liquid trapped between layers of felt or membrane.

Blocking: Pieces of wood installed into a roof assembly used to stiffen the deck around an opening, support a curb or serve as a nailer for attaching flashings or membranes.

Built-Up Roof (BUR): A continuous, semi-flexible roof membrane consisting of layers of felts, fabrics or mats installed with binding layers of bitumen. A top layer of asphalt, emulsion or a granule-surfaced cap sheet is then generally applied.

Bundle: An individual package of shingles or shakes.

Butt Joint: A joint where two separate sections of material abut.

Back to top


Cant Strip: A beveled strip of material used to modify the transition from a horizontal plane to a vertical plane.

Cap Sheet: The top ply of a BUR or modified roof system that usually has a granulated surface.

Caulk: A mastic used to seal a joint or crack or the act of sealing a joint or crack. Closure Strip: A material, such as neoprene, used to close openings created by joining metal panels or a similar material used to fill gaps between adjoining dissimilar materials, e.g. wood to metal.

Composition Shingle: A shingle manufactured by coating a fiberglass-reinforcing mat with asphalt and applying mineral granules to the exposed surface.

Concealed-Nailing: See Blind-Nail

Course: Horizontal row of shingles or rolled roofing running the length of the roof.

Coverage: The surface area covered by a specific quantity of material.

Cricket: A vaulted roof component constructed to divert water from flat sections of a roof. See Saddle.

Cross Ventilation: The effect of air moving between vents in a roof cavity.

Cupola: A relatively small roofed structure set on the ridge or peak of a main roof which is used for ventilation or aesthetic purposes.

Curb: (1) A raised member used to support roof penetrations such as skylights, exhaust fans, etc. above the roof surface. (2) A raised roof perimeter relatively low in height.

Cutout: The open area between the tabs of a strip shingle. Also known as a keyway.

Back to top


Deck: The surface, installed over the supporting framing members (joists or rafters), to which the roofing materials are applied.

Delamination: The separating of laminated layers of a material or system.

Dimensional Shingle: A shingle that is designed and manufactured to produce a three-dimensional effect. Also known as Laminated or Architectural Shingles.

Dormer: A framed structure, usually housing a window or ventilating louver, projecting through the sloping plane of a roof.

Drip Edge: A metal flashing used along the eaves and rakes to allow water run-off to drip clear of the building.

Dry-In: The process of applying felt underlayment in steep slope roofing.

Back to top


Eave: The horizontal, lower edge of a sloping roof that projects beyond the wall.

Emulsion: A combination of bitumen and water with consistent dispersion of the bitumen or water globules.

Exhaust Vent: A device located on or near the roof ridge that allows air to escape from the roof cavity.

Exposed-Nail Method: A method of nailing roofing where the nail is exposed to the weather.

Exposure: The portion of roofing material not covered by the succeeding course or ply.

Back to top


Fascia: Roof trim, typically wood, located along the perimeter of a building, usually just below the roof level.

Feathering Strips: Strips of wood that are placed along the butt ends of wood shingles to form a relatively smooth surface when reroofing over existing wood shingles.

Felt: A mat made of interwoven fibers and a binder to be used as underlayment. Fibers usually used are fiberglass or wood pulp and vegetable fibers (organic felts).

Field of the Roof: Refers to the main part of a roof excluding the perimeter and flashings.

Fishmouth: A half-conical shaped opening or void along the exposed edge of a seam or shingle.

Flashing: Components, usually metal, used to prevent water seepage into a building around roof intersections or projections such as dormers, valleys, chimneys, etc.

Back to top


Gable: The upper portion of a sidewall that comes to a triangular point at the ridge of a sloping roof.

Gable Roof: A style of roof that has gable ends.

Gambrel: A style of roof that has two different pitches on each side, where the lower plane has a steeper pitch than the upper.

Gauge: A standard of measurement used to measure the thickness of metal.

Granule: A small crushed mineral, naturally or synthetically colored that is applied to the exposed surface of roofing products.

Gutter: A trough, typically metal, installed along the eaves of a roof to convey runoff water from the roof to the downspouts.

Back to top


Hand-Tabbing: Applying spots of adhesive to the underside of composition shingles.

Hip: The inclined angle formed by the intersection of two sloping roof planes.

Hip Roof: A style of roof that rises by inclined planes in all sides of a building. This roof has no gables.

HVAC: Heating, Ventilating, and Air Conditioning.

Back to top


ICBO: International Conference of Building Officials

Ice Dam: (1)The condition formed by the refreezing of melted water usually at the eaves and in gutters, which causes water to backup under roofing materials. (2) A self adhering rolled product applied to prevent this condition.

Insect Screen: Wire or fiberglass mesh used to prevent insects from entering a building through openings in a roof such as vents.

Interlocking Shingles: Individual shingles that lock together to provide wind resistance.

Back to top


Laminated Shingle: See Dimensional Shingle.

Low-Slope Application: A method of installing composition shingles on roofs with pitches between 2:12 and 4:12.

Back to top


Mansard: A steep-sloped roof located at the perimeter of a building usually used for aesthetic purposes.

Mastic: See Asphalt Roof Cement.

Material Safety Data Sheets (MSDS): Written safe handling procedures and emergency instructions provided by the manufacturers used to describe their products and ingrediants.

Membrane: The portion of the roofing system that is the primary waterproofing material. It can be composed of one or several materials laminated together.

Mopping: The application of hot asphalt or coat tar using a mop or mechanical applicator to the surface or plies of a roofing membrane.

Back to top


Nailer: See Blocking.

Nesting: A method of reroofing by butting the new asphalt shingle up against the bottom of the existing shingle.

NRCA: National Roofing Contractors Association.

NTRMA: National Tile Roofing manufacturers Association.

Back to top


Open Valley: A valley in which both sides of the roof slope are trimmed to expose the valley flashing.

Organic Felt: A reinforced underlayment material manufactured from cellulose fibers.

Organic Shingle: An asphalt shingle reinforced with material manufactured from cellulose fibers.

OSB: Oriented Strand Board. Often used as roof sheathing in lieu of plywood.

Back to top


Parapet Wall: The portion of a perimeter wall that extends above the surface of the roof.

Perm: A unit of water vapor transmission.

Pipe Boot: A manufactured flashing used to flash around pipe penetrations. Also known as Roof Jacks.

Pitch: A term used to describe the slope of the roof.

Ply: A layer of reinforcement material in a roof system.

Ponding: The excessive accumulation of water at low-lying areas common on a flat roof.

Back to top


Rafter: The structural member immediately under the roofing deck, sloping from the ridge to the hip or eave. Also called a joist.

Rake: The perimeter edge of a roof that runs from the eaves to the ridge.

Re-Cover: The application of a new roof system over an existing system.

Release Tape: A strip, usually plastic, applied to the back of a self-sealing composition shingle that prevents the shingles from sticking together in the bundles.

Ridge: A horizontal line where two roof planes intersect represented by the highest point on the roof.

Ridge Cap: Material installed over the ridge or hip of a roof.

Ridge Vent: A venting device located at the ridge of a roof that allows warm and/or moist air to escape from the roof cavity.

Roll Goods: A general term used for roofing materials that are furnished in a roll.

Roof Assembly: A description of all the components, including the deck that make up a roof.

Roof Jack: (1) A steel bracket temporarily fastened to the roof that is used to support toe boards. (2) A term used to describe a Pipe Boot or Vent Flashing.

Roof Slope: The angle of roof incline expressed as the ratio between the rise (in inches) and run (in inches). Example: a roof that rises 4″ for every 12″ of run is expressed as 4:12.

Run: The horizontal distance from the eaves to the point directly under the ridge.

Back to top


Saddle: A small pyramid-shaped structure usually located in a valley that diverts run-off water.

Saturated Felt: An asphalt impregnated felt used as an underlayment.

Self-Sealing Shingle: Composition shingles with factory applied strips of self-sealing adhesive to the underside of the shingle.

Shading: Slight differences in the color of shingles that occur during manufacturing.

Shed Roof: A roof with only one sloping plane.

Shingle: (1) A single piece of prepared roofing material used with similar pieces in overlapping runs or courses in steep slope roof systems. (2) The installation of shingles.

Slope: The degree of incline of a roof usually expressed as a ratio of rise to run.

Soffit: The exposed underside of a roof overhang.

Square: A unit of measurement equal to 100 square feet of roof area.

Starter Course: The first course of roofing materials installed along the downslope perimeter edge. The starter course is usually covered by the first course of roofing.

Starter Strip: Shingle strips or rolled roofing material that is laid along the eave line prior to the installation of the first course of shingles. The starter strip fills in the gaps created by shingle cutouts and joints.

Steep-Slope Roof: A roof with a slope exceeding 3:12.

Step Flashing: Individual pieces of flashing material applied so they overlap and are stepped up the vertical surface. Typically used to flash chimneys, walls, curbs, etc.

Substrate: The surface to which the roof is applied. Also called the deck or roof deck.

Back to top


Tab: The exposed portion of a strip shingle that is outlined by the cutouts.

Tear-Off: The removal of a roof system down to the deck.

Tear Resistance: The force required to tear material, measured in PSI, when concentrated on a small area of the material. Quality composition shingles have superior tear resistance.

Tear Strength: The force or load required to tear material.

Throat: The cutout of a shingle.

Back to top


UBC: Uniform Building Code.

UL: Underwriters Laboratories Inc.

Underlayment: A material, usually asphalt impregnated felt (which provides additional protection from the water) installed between the roofing and deck.

Back to top


Valley: The internal intersection of two sloping roof planes that runs from the eaves to the ridge.

Vent: An opening or device that allows the ventilation of an enclosed structure such as an attic.

Back to top


Woven Valley: A valley construction in which shingles from both sides of the valley are woven together by overlapping alternating courses of shingles.

Back to top