Glossary of Roofing Terms

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ALGAE – Rooftop fungus that can leave dark stains on roofing.
AMERICAN METHOD – Application of giant individual shingles with the dimension parallel to the rake. Shingles are applied with a 3/4″ inch space between adjacent shingles in a course.
ANGLED FASTENERS – Roofing nails and staples driven into decks at angles not parallel to the deck.
APA – American Plywood Association, who tests and sets standards for all varieties of plywood used in the U.S.
APRON FLASHING – Metal flashing used at chimney fronts.
ARMA – Asphalt Roofing Manufacturer’s Association, an organization of roofing manufacturers.
ASPHALT – A bituminous waterproofing agent used in various types of roofing materials.
ASPHALT CONCRETE PRIMER – Asphalt based primer used to prepare concrete and metal for asphalt sealant.
ASPHALT PLASTIC CEMENT – Asphalt based sealant material, meeting ASTM D4586 Type I or II. Used to seal and adhere roofing materials. Also called mastic, blackjack, roof tar, bull.
ASTM – The American Society for Testing and Materials, an organization that sets standards for a wide variety of materials, including roofing.


BACK-SURFACING – Granular material added to shingle’s back to assist in keeping separate during delivery and storage.
BASE FLASHING – That portion of the flashing attached to or resting on the deck to direct the flow of water onto the roof covering.
BLISTERING – Bubbles or pimples in roofing materials. Usually moisture related. In shingles blisters are either moisture under the material or moisture trapped inside the material.
BLOW-OFFS – When shingles are subjected to high winds, and are forced off a roof deck.
BRANDS – Airborne burning embers released from a fire.
BRIDGING – A method of re-roofing with metric-sized shingles.
BUCKLING – When a wrinkle or ripple affects shingles or their underlayments.
BUILT-UP ROOF – A flat or low-sloped roof consisting of multiple layers of asphalt and ply sheets.
BUNDLE – A package of shingles. There are 3, 4 or 5 bundles per square. A group of shingles held together, as by tying or wrapping.
BUTT EDGE – The lower edge of the shingle tabs.


CAULK – To fill a joint with mastic or asphalt cement to prevent leaks.
CEMENT – See Asphalt Roofing Cement.
CHALK LINE – A line made on the roof by snapping a taut string or cord dust with chalk. Used for alignment purposes.
CLASS “A” – The highest fire-resistance rating for roofing as per ASTM E-108. Indicates roofing is able to withstand severe exposure to fire originating from sources outside the building.
CLASS “B” – Fire-resistance rating that indicates roofing material is able to withstand moderate exposure to fire originating from sources outside the building.
CLASS “C” – Fire-resistance rating that indicates roofing material is able to withstand light exposure to fire originating from sources outside the building.
CLOSED-CUT VALLEY – A shingle valley installation method where one roof plane’s shingles completely cover another. The top layer is cut to match the valley lines.
COATING – A layer of viscous asphalt applied to the base material into which granules or other surfacing is embedded.
COLLAR – Pre-formed flange placed over a vent pipe to seal the roof around the vent pipe opening. Also called a vent sleeve.
CONCEALED NAIL METHOD – Application 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.
CONDENSATION – The change of water from to vapor to liquid when warm, moisture-laden air comes in contact with a cold surface.
CORROSION – When rust, rot or age negatively affect roofing metals.
COUNTER-FLASHING – The metal or siding material that is installed over roof-top base flashing systems.
COURSE – A row of shingles or roll roofing running the length of the roof.
COVERAGE – Amount 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; i.e. single coverage, double coverage, etc.
CRICKETS – A peaked water diverter installed behind chimneys and other large roof projections. Effectively diverts water around projections.
CUPPING – When shingles are improperly installed over an existing roof or are over-exposed, they form a curl or cup.
CUTOUT – The open portions of a strip shingle between the tabs.


DECK – The substrate over which roofing is applied. Usually plywood, wood boards, or planks.
DORMER – A raised roof extending out of a larger roof plane.
DOUBLE COVERAGE – Application of asphalt roofing such that the lapped portion is at least 2 inches wider than the exposed portion, resulting in two layers of roofing material over the deck.
DOWNSPOUT – A pipe for draining water from roof gutters. Also called a leader.
DRIP EDGE – A non-corrosive, non-staining material used along the eaves and rakes to allow water run-off to drip clear of underlying construction.
DUTCH LAP METHOD – Application of giant individual shingles with the long dimension parallel to the eaves.


EAVES – This is the lower, overhanging part of your roof. Typically where the gutter is located is called the eave line.
EAVES FLASHING – Additional layer of roofing material applied at the eaves to help prevent damage from water back-up.
EDGING STRIPS – Boards nailed along eaves and rakes after cutting back existing wood shingles to provide secure edges for re-roofing with asphalt shingles.
ELL – An extension of a building at right angles to its length.
END-LAPS – When installing rolled products (i.e., rolled roofing, underlayments) in roofing, the area where a roll ends on a roof, and is overlapped by the next section of rolled material.
EXPOSED NAIL METHOD – Application of roll roofing in which all nails are driven into the cemented, overlapping course of roofing. Nails are exposed to the weather.
EXPOSURE – Vulnerability to the elements; to the action of heat or cold or wind or rain; “exposure to the weather.”
EXPOSURE I GRADE PLYWOOD – Type of plywood approved by the American Plywood Association for exterior use.


FASTENERS – Nails or staples used in securing roofing to the deck. Felt-Organic or paper-based rolled material saturated with asphalt to serve as roofing underlayment.
FEATHERING STRIPS – Tapered wood filler strips placed along the butts of old wood shingles to create a level surface when re-roofing over existing wood shingles to provide secure edges for re-roofing with asphalt.
FELT – Fibrous material saturated with asphalt and used as an underlayment or sheathing paper.
FHA – The Federal Housing Authority, who sets construction standards throughout the U.S.
FIBERGLASS MAT – fibers condensed into strong, resilient mats for use in roofing materials.
FIRE RATING – Measurement used by independent labs to determine resistance to fire.
FLANGE – Metal pan extending up or down a roof slope around flashing pieces. Usually at chimneys and plumbing vents
FLASHING – Materials used to waterproof a roof around any projections through the roof deck.
FLASHING CEMENT – Sealant designed for use around flashing areas, typically thicker than plastic cement.
FM – Factory Mutual Research Corp.
FREE-TAB SHINGLES – Shingles that do not contain factory-applied strips or spots of self-sealing adhesive.


GABLE – The upper portion of a sidewall that comes to a triangular point at the ridge of a sloping roof.
GABLE ROOF – A type of roof containing two sloping planes of the same pitch on each side of the ridge. Contains a gable at each end.
GAMBREL ROOF – A 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. Contains a gable at each end.
GRANULES – Ceramic-coated colored crushed rock that is applied to the exposed surface of asphalt roofing products.
GUTTER – The trough that channels water from the eaves to the downspouts.


HAND-SEALING – The method used to ensure sealing of shingles on very steep slopes, in high wind areas, and when installing in cold weather.
HEAD LAP – Shortest 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 SHINGLES – Shingles that have the appearance of a hexagon after installation.
HIGH NAILING – When shingles are nailed or fastened above the manufacturer’s specified nail location.
HIP – The inclined external angle formed by the intersection of two sloping roof planes. Runs from the ridge to the eaves.
HIP LEGS – The down-slope ridges on hip roofs.
HIP ROOF – A roof with four roof planes coming together at a peak and four separate hip legs.
HIP SHINGLES – Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.
HORSEFEATHERS – See feathering strips.


ICE DAM – When a snow load melts on a roof and re-freezes at the eave areas. Ice dams force water to “back-up” a roof and cause leakage.
INTERLOCKING SHINGLES – Individual shingles that mechanically fasten to each other to provide wind resistance.


L FLASHING – Continuous metal flashing consisting of several feet of metal. Used at horizontal walls, bent to resemble an “L”.
LAMINATED SHINGLES – Shingles made from two separate pieces that are laminated together. Also called dimensional shingles and architectural shingles.
LAPS – The area where roll roofing or rolled underlayments overlap one another during application (see also side laps and end laps).
LOW SLOPES – Roof pitches less than 4/12 are considered low sloped roofs. Special installation practices must be used on roofs sloped 2/12-4/12.


MANSARD – A roof design with a nearly vertical roof plane that ties into a roof plane of less slope at its peak.
MANSARD ROOF – A 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. Contains no gables.
MASONRY PRIMER – An asphalt-based primer used to prepare masonry surfaces for bonding with other asphalt products.
MASTIC – Asphalt-based sealant. Applied with a trowel or by hand using rubber gloves. Other trades have other types of mastic products.
MATS – The general term for the base material of shingles and certain rolled products.
MINERAL STABILIZERS – Finely ground limestone, slate, trap-rock or other inert materials added to asphalt coatings for durability and increased resistance to fire and weathering.
MINERAL-SURFACED ROOFING – Asphalt shingles and roll roofing that are covered with granules.
MODIFIED BITUMEN – Rolled roofing membrane with polymer modified asphalt and either polyester or fiberglass reinforcement.
MORTAR – Mixture of sand, mortar, limestone and water used in bonding a chimney’s bricks together.


NAIL-GUIDE-LINE – Painted line on laminated shingles designed to aid in the proper placement of fasteners.
NAIL-POP – When a nail is not fully driven, it sits up off the roof deck.
NESTING – Installing a second layer of shingles aligning courses with the original roof to avoid shingle cupping.
NO-CUTOUT SHINGLES – Shingles consisting of a single, soled tab with no cutouts.
NON-VENEER PANEL – Any wood-based panel that does not contain veneer and carries an APA span rating, such as wafer board or oriented strand board.
NORMAL SLOPE APPLICATION – Method of installing asphalt shingles on roof slopes between 4 inches and 21 inches per foot.
NRCA – The National Roofing Contractors Association; a respected national organization of roofing contractors.


OPEN VALLEY – Valley installation using metal down the valley center.
ORGANIC FELT – An asphalt roofing base material manufactured from cellulose fibers.
ORGANIC MAT – Material made from recycled wood pulp and paper.
ORGANIC SHINGLES – Shingles made from organic (paper) mats.
OSB – Oriented Strand Board; a decking made from wood chips and lamination glues.
OVER-DRIVEN – The term used for fasteners driven through roofing material with too much force, breaking the material.
OVER-EXPOSED – Installing shingle courses higher than their intended exposure.
OVERHANG – That portion of the roof structure that extends beyond the exterior walls of a building.


PALLETS – Tile and other materials when purchased in quantity will come on a pre-built wooden structure. This is a pallet and the place where a forklift would put the forks to lift the entire amount.
PITCH – ratio of the rise of the roof to the span of the roof.
POWER VENTS – Electrically powered fans used to move air from attics and structures.
PLASTIC CEMENT- Asphalt based sealant. Also called bull, mastic, tar, asphalt cement.
PLUMBING VENTS – Term used to describe plumbing pipes that project through a roof plane. Also called vent stacks.
PLY – The number of layers of roofing; i.e., one-ply, two-ply.
PREVAILING WIND – The most common direction of wind for a particular region.


QUICK-SETTING CEMENT – 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.


RACKING – Method of installing shingles in a straight up the roof manner.
RAFTER – The supporting framing member immediately beneath the deck, sloping from the ridge to the wall.
RAKE – The inclined edge of a sloped roof over a wall from the eave to the ridge.
RAKE EDGE – The vertical edge of gable style roof planes.
RANDOM-TAB SHINGLES – Shingles on which tabs vary in size and exposure.
RELEASE FILM – The plastic sheet installed on the back of underlayments. Used for packaging and handling.
RELEASE TAPE – A 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.
RIDGE – The uppermost, horizontal external angle formed by the intersection of two sloping roof planes.
RIDGE SHINGLES – Shingles used to cover the horizontal external angle formed by the intersection of two sloping roof planes.
RIGID VENT- Hard plastic ridge vent material.
RISE – The vertical distance from the eaves line to the ridge.
ROLL ROOFING – Asphalt roofing products manufactured in roll form.
ROOF LOUVERS – Rooftop rectangular shaped roof vents. Also called box vents, mushroom vents, airhawks, soldier vents.
ROOF PLANE – A roofing area defined by having four separate edges. One side of a gable, hip or mansard roof.
ROOFING TAPE – Saturated tape used with asphalt cements for flashing and patching asphalt roofing.
RUN – The horizontal distance from the eaves to a point directly under the ridge. One-half the span.


SATURANT – Asphalt used to impregnate an organic felt base material.
SATURATED FELT – An asphalt-impregnated felt used as an underlayment between the deck and the roofing material.
SELF-SEALING STRIP OR SPOT – Factory-applied adhesive that bonds shingle courses together when exposed to the heat of the sun after application.
SELVAGE – That portion of roll roofing overlapped by the succeeding course to obtain double coverage.
SHADING – Slight differences in shingle color that may occur as a result of normal manufacturing operations.
SHEATHING – Exterior grade boards used as a roof deck material.
SHED ROOF – A roof containing only one sloping plane. Has no hips, ridges, valleys or gables.
SHINGLE COVERAGE – Shingles containing factory-applied strips or spots of self-sealing adhesive.
SIDE-LAPS – The area on rolled material where one roll overlaps the rolled material beneath it. Also called selvage edge on rolled roofing.
SIDE-WALLS – Where a vertical roof plane meets a vertical wall. The sides of dormers etc.
SINGLE COVERAGE – Asphalt roofing that provides one layer of roofing material over the deck.
SLOPE – The degree of roof incline expressed as the ratio of the rise, in inches, to the run, in feet.
SMOOTH-SURFACED ROOFING – Roll roofing that is covered with ground talc or mica instead of granules.
SOFFIT – The finished underside of the eaves.
SOFFIT VENTILATION – Intake ventilation installed under the eaves, or at the roof edge.
SPAN – The horizontal distance from eaves to eaves.
SQUARE – A unit of roof measure covering 100 square feet.
SQUARE-TAB SHINGLES – Shingles on which tabs are all the same size and exposure.
STARTER STRIP – Asphalt roofing applied at the eaves that provides protection by filling in the spaces under the cutouts and joints of the first course of shingles.
STEEP SLOPE APPLICATION – Method of installing asphalt shingles on roof slopes greater than 21 inches per foot.
STEP FLASHING – Flashing application method used where a vertical surface meets a sloping roof plane.
STRIP SHINGLES – Asphalt shingles that are approximately three times as long as they are wide.
SELF-SEALANT – Sealant installed on shingles. After installation, heat and sun will activate sealant to seal the shingles to each other.


TAB – The bottom portion of traditional shingle separated by the shingle cut-outs.
TEAR-OFF – Removal of existing roofing materials down to the roof deck.
TELEGRAPHING – When shingles reflect the uneven surface beneath them. Shingles installed over buckled shingles may show some buckles.
THREE DIMENSIONAL SHINGLES – See laminated shingles.
TOP LAP – That portion of the roofing covered by the succeeding course after installation.
TRANSITIONS – When a roof plane ties into another roof plane that has a different pitch or slope.


UL – Underwriters Laboratories, Inc.
UL LABEL – Label displayed on packaging to indicate the level of fire and/or wind resistance of asphalt roofing.
UNDER-DRIVEN – Term used to describe a fastener not fully driven flush to the shingles surface.
UNDERLAYMENTS – Asphalt based rolled materials designed to be installed under main roofing material, to serve as added protection.


VALLEYS – Area where two adjoining sloped roof planes intersect on a roof creating a “V” shaped depression.
VAPOR – Term used to describe moisture laden air.
VAPOR RETARDER – Any material used to prevent the passage of water vapor.
VENT – Any outlet for air that protrudes through the roof deck, such as a pipe or stack. Any device installed on the roof or gable for the purpose of ventilating the underside of the roof deck.
VENT SLEEVE – See collar.
VENTILATION – The term used in roofing for the passage of air from an enclosed space.


WARM WALL – The finished wall inside of a structure, used in roofing to determine how to install waterproof underlayments at eaves.
WARRANTY – The written promise to the owner of roofing materials for material related problems.
WATERPROOF UNDERLAYMENTS – Modified bitumen based roofing underlayments. Designed to seal on to wood decks and waterproof critical leak areas.
WOVEN VALLEYS – The method of installing valleys by laying one shingle over the other up the valley center.

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