Algae discolorationA type of roof discoloration caused by algae. Commonly called fungus growth.
American methodApplication of very large individual shingles with the long dimension parallel to the rake. Shingles are applied with a 3/4-inch space between adjacent shingles in a course.
AsphaltA bituminous waterproofing agent applied to roofing materials during manufacturing.
Asphalt roofing cementAn asphalt-based cement used to bond roofing materials. Also known as flashing cement or mastic; should conform to ASTM D4586.
Back surfacingFine mineral matter applied to the back side of shingles to keep them from sticking.
Balanced systemA ventilation system where 50% of the required ventilating area is provided by vents located in the upper portion of the roof with the balance provided by undereave or soffit vents.
Base flashingThat portion of the flashing attached to or resting on the deck to direct the flow of water onto the roof covering.
BlistersBubbles that may appear on the surface of asphalt roofing after installation.
BrandsAirborne burning embers released from a fire.
BridgingA method of reroofing with metricsized shingles.
Built-up roofA flat or low-slope roof consisting of multiple layers of asphalt and ply sheets.
BundleA package of shingles. There are 3, 4 or 5 bundles per square.
Butt edgeThe lower edge of the shingle tabs.
CaulkTo fill a joint with mastic or asphalt cement to help prevent leaks.
CementSee asphalt roofing cement.
Chalk lineA line made on the roof by snapping a taut string or cord dusted with chalk. Used for alignment purposes.
Class "A"The highest fire-resistance rating for roofing as per ASTM E108. Indicates roofing is able to withstand severe exposure to fire originating from sources outside the building.
Class "B" Fire-resistance rating that indicates roofing materials are able to withstand moderate exposure to fire originating from sources outside the building.
Class "C"Fire-resistance rating that indicates roofing materials are able to withstand light exposure to fire originating from sources outside the building.
Closed cut valleyA method of valley treatment in which shingles from one side of the valley extend across the valley, while shingles from the other side are trimmed two inches from the valley centerline. The valley flashing is not exposed.
CoatingA layer of viscous asphalt applied to the base material into which granules or other surfacing is embedded.
CollarPre-formed flange placed over a vent pipe to seal the roof around the vent pipe opening. Also called a vent sleeve.
Concealed nail methodApplication of roll roofing in which all nails are driven into the underlying course of roofing and covered by a cemented, overlapping course. Nails are not exposed to the weather.
CondensationThe change of water from vapor to liquid when warm, moisture-laden air comes in contact with a cold surface.
Counter flashingThat portion of the flashing attached to a vertical surface to help prevent water from migrating behind the base flashing.
CoverageAmount of weather protection provided by the roofing material. Depends on number of layers of material between the exposed surface of the roofing and the deck (single coverage, double coverage, etc.).
CricketA peaked saddle construction at the back of a chimney to help prevent accumulation of snow and ice and to deflect water around the chimney.
CutoutThe open portions of a strip shingle between the tabs.
DamperAn adjustable plate for controlling draft.
DeckThe surface installed over the supporting framing members to which the roofing is applied.
DormerA framed window unit projecting through the sloping plane of a roof.
Double coverageApplication of asphalt roofing such that the lapped portion is at least two inches wider than the exposed portion, resulting in two layers of roofing material over the deck.
DownspoutA pipe for draining water from roof gutters. Also called a leader.
Drip edgeA noncorrosive, nonstaining material used along the eaves and rakes to allow water runoff to drip clear of underlying construction.
Dutch lap methodApplication of very large individual shingles with the long dimension parallel to the eaves. Shingles are applied to overlap adjacent shingles in each course as well as the course below.
EavesThe horizontal, lowest edge of a sloped roof that extends beyond the exterior wall.
Eaves flashingAdditional layer of roofing material applied at the eaves to help prevent damage from water backup.
Edging stripsBoards nailed along eaves and rakes after cutting back existing wood shingles to provide secure edges for reroofing with asphalt shingles.
EllAn extension of a building at right angles to its length.
Exposed nail methodApplication of roll roofing in which all nails are driven into the cemented, overlapping course of roofing. Nails are exposed to the weather.
Exposure I grade plywoodType of plywood approved by the American Plywood Association for exterior use.
Feathering stripsTapered wood filler strips placed along the butts of old wood shingles to create a level surface when reroofing over existing wood shingle roofs. Also called horsefeathers.
FeltFibrous material saturated with asphalt and used as an underlayment or sheathing paper.
Fiberglass matAn asphalt roofing base material manufactured from glass fibers.
Flashing cementSee asphalt roofing cement.
FMFactory Mutual Research Corp.
Free-tab shinglesShingles that do not contain factory-applied strips or spots of self-sealing adhesive.
GableThe upper portion of a sidewall that comes to a triangular point at the ridge of a sloping roof.
Gable roofA type of roof containing a sloping plane on each side of a single ridge with a gable at each end.
Gambrel roofA type of roof containing two sloping planes of different pitch on each side of the ridge. The lower plane has a steeper slope than the upper. Features a gable at each end.
GranulesCeramic-coated colored crushed rock that is applied to the exposed surface of asphalt roofing products.
GutterThe trough that channels water from the eaves to the downspouts.
Head lapShortest distance from the butt edge of an overlapping shingle to the upper edge of a shingle in the second course below. The triple coverage portion of the top lap of strip shingles.
HEX shinglesShingles that have the appearance of a hexagon after installation.
HipThe inclined external angle formed by the intersection of two sloping roof planes. Runs from the ridge to the eaves.
Hip roofA type of roof containing sloping planes of the same pitch on each of four sides. Contains no gables.
Hip shinglesShingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.
HorsefeathersSee feathering strips.
Ice damCondition formed at the lower roof edge by the thawing and refreezing of melted snow on the overhang. Can force water up and under shingles, causing leaks.
Interlocking shinglesIndividual shingles that mechanically fasten to each other to provide wind resistance.
Laminated shinglesStrip shingles containing more than one layer of tabs to create extra thickness. Also called dimensional or architectural shingles.
Lap cementAn asphalt-based cement used to adhere overlapping plies of roll roofing.
LouverA slanted opening for ventilation.
Low slope applicationMethod of installing asphalt shingles on roof slopes between two and four inches per foot.
Mansard roofA type of roof containing two sloping planes of different pitch on each of four sides. The lower plane has a much steeper pitch than the upper, often approaching vertical. Includes no gables.
Masonry primerAn asphalt-based primer used to prepare masonry surfaces for bonding with other asphalt products.
MasticSee asphalt plastic roofing cement.
Mineral stabilizersFinely ground limestone, slate, traprock or other inert materials added to asphalt coatings for durability and increased resistance to fire and weathering.
Mineral-surfaced roofingAsphalt shingles and roll roofing that are covered with granules.
Natural ventilationA ventilation system utilizing ventilators installed in openings in the attic and properly positioned to take advantage of natural air flow to draw hot summer or moist winter air out and replace it with fresh outside air.
NestingA method of reroofing with new asphalt shingles over old shingles in which the top edge of the new shingle is butted against the bottom edge of the existing shingle tab.
Net Free Vent Area (NFVA)Area unobstructed by screens, louvers or other materials.
No-cutout shinglesShingles consisting of a single, solid tab with no cutouts.
Non-veneer panelAny wood-based panel that does not contain veneer and carries an APA span rating, such as wafer board or oriented strand board.
Normal-slope applicationMethod of installing asphalt shingles on roof slopes between 4 inches and 21 inches per foot.
Open valleyMethod of valley construction in which shingles on both sides of the valley are trimmed along a chalk line snapped on each side of the valley. Shingles do not extend across the valley. Valley flashing is exposed.
Organic feltAn asphalt roofing base material manufactured from cellulose fibers.
OverhangThat portion of the roof structure that extends beyond the exterior walls of a building.
PalletsWooden platforms used for storing and shipping bundles of shingles.
PitchThe degree of roof incline expressed as the ratio of the rise, in feet, to the span, in feet.
PlyThe number of layers of roofing (e.g. one-ply, two-ply).
Quick-setting cementAn asphalt-based cement used to adhere tabs of strip shingles to the course below. Also used to adhere roll roofing laps applied by the concealed nail method.
RackingRoofing application method in which shingle courses are applied vertically up the roof rather than across and up. Not a recommended procedure.
RafterThe supporting framing member immediately beneath the deck, sloping from the ridge to the wall plate.
RakeThe inclined edge of a sloped roof over a wall from the eave to the ridge.
Random-tab shinglesShingles on which tabs vary in size and exposure.
Release tapeA plastic or paper strip that is applied to the back of self-sealing shingles. This strip prevents the shingles from sticking together in the bundles and need not be removed for application.
RidgeThe uppermost, horizontal external angle formed by the intersection of two sloping roof planes.
Ridge shinglesShingles used to cover the horizontal external angle formed by the intersection of two sloping roof planes.
RiseThe vertical distance from the eaves line to the ridge.
Roll roofingAsphalt roofing products manufactured in roll form.
Roofing cementA compound used to seal flashings, seal down shingles and for other small waterproofing jobs. Where cement is required for sealing down shingles, use a dab about the size of a quarter unless otherwise specified.
Roofing tapeAn asphalt-saturated tape used with asphalt cements for flashing and patching asphalt roofing.
RunThe horizontal distance from the eaves to a point directly under the ridge. One half the span.
SaturantAsphalt used to impregnate an organic felt base material.
Saturated feltAn asphalt-impregnated felt used as an underlayment between the deck and the roofing material.
Self-sealing cementA thermal-sealing tab cement built into the shingle to firmly cement the shingles together automatically after they have been applied properly and exposed to warm sun temperatures. In warm seasons, the seal will be complete in a matter of days. In colder seasons, sealing time depends on the temperature and amount of direct sunlight hitting the shingles. Hand sealing with cement should be done to ensure sealing in winter.
Self-sealing shinglesShingles containing factory-applied strips or spots of self-sealing adhesive.
Self-sealing strip or spotFactory-applied adhesive that bonds shingle courses together when exposed to the heat of the sun after application.
SelvageThat portion of roll roofing overlapped by the succeeding course to obtain double coverage.
ShadingSlight differences in shingle color that may occur as a result of normal manufacturing operations.
SheathingExterior-grade boards used as a roof deck material.
Shed roofA roof containing only one sloping plane. Has no hips, ridges, valleys or gables.
Single coverageAsphalt roofing that provides one layer of roofing material over the deck.
SlopeThe degree of roof incline expressed as the ratio of the rise, in inches, to the run, in feet.
Smooth-surfaced roofingRoll roofing that is covered with ground talc or mica instead of granules (coated).
Soil stackA vent pipe that penetrates the roof.
SpanThe horizontal distance from eaves to eaves.
Specialty eaves flashing membraneA self-adhering, waterproofing shingle underlayment designed to protect against water infiltration due to ice dams or wind-driven rain.
Square-tab shinglesShingles on which tabs are all the same size and exposure.
Steep-slope application (Mansard)Method of installing asphalt shingles on roof slopes greater than 21 inches per foot.
Step flashingFlashing application method used where a vertical surface meets a sloping roof plane.
Strip shinglesA single-layer shingle commonly known as a three-tab shingle because it has three tabs.
TabThe exposed portion of strip shingles defined by cutouts.
TelegraphingA shingle distortion that may arise when a new roof is applied over an uneven surface.
Three-dimensional shinglesSee laminated shingles.
Three-tab shingleA single-layer shingle having three tabs.
Top lapThat portion of the roofing covered by the succeeding course after installation.
ULUnderwriters Laboratories, LLC.
UL labelLabel displayed on packaging to indicate the listing for fire and/or wind resistance of asphalt roofing.
UndereaveUnderside area of the overhang at the eave of the roof.
ValleyThe internal angle formed by the intersection of two sloping roof planes to provide water runoff.
Vapor retarderAny material used to prevent the passage of water vapor. Material which, when installed on the high-vapor-pressure (warm in winter) side of a material, retards the passage of moisture vapor to the lower-pressure (cold in winter) side. Note exception: Florida and Gulf Coast. Check local building codes to determine on which side the vapor retarder should be placed.
VentAny outlet for air that protrudes through the roof deck, such as a pipe or stack. Any device installed on the roof, gable or soffit for the purpose of ventilating the underside of the roof deck.
VentilatorsDevices that eject stale air and circulate fresh air (e.g. ridge, roof, gable, undereave, foundation or rafter vents and vented soffit panels).
Woven valleyMethod of valley construction in which shingles from both sides of the valley extend across the valley and are woven together by overlapping alternate courses as they are applied. The valley flashing is not exposed.
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