Algae – Rooftop fungus that can leave dark stains on roofing.
Angled fasteners – Roofing nails and staples driven into decks at angles not parallel to the deck.
APA – American Plywood Association. Tests and sets standards for all varieties of plywoods used in the U.S.
Apron flashing – Metal flashing used at chimney fronts.
ARMA – Asphalt Roofing Manufacturer’s Association. 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. 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.
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.
Buckling – When a wrinkle or ripple affects shingles or their underlayments.
Closed-cut valley – A shingle valley installation method where one roof plane’s shingles completely cover the other’s. The top layer is cut to match the valley lines.
Cobra® – GAFMC’s respected brand name for ventilation products.
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.
Country Mansion® & Country Estates™ – GAFMC’s limited lifetime warranty shingle.
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.
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.
Drip-edge – An installed lip that keeps shingles up off of the deck at edges, and extends shingles out over eaves and gutters, and prevents water from backing up under shingles.
Dubl-Coverage® Mineral Guard – Roll roofing material with 19″ selvage edge for double coverage over roof deck.
Eaves – The roof edge from the fascia to the structure’s outside wall. In general terms, the first three feet across a roof is termed the eave.
End-laps – When installing rolled products in roofing, the area where a roll ends on a roof, and is overlapped by the next section of rolled material. (underlayments, rolled roofing)
Exposure – The area on any roofing material that is left exposed to the elements.
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.
FHA -The Federal Housing Authority. Sets construction standards throughout the U.S.
Fiberglass mat – fibers condensed into strong, resilient mats for use in roofing materials.
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.
Gable roof – Traditional roof style; two peaked roof planes meeting at a ridge line of equal size.
GAFCant® – GAFMC cant strips for deflecting water away from flashing areas. Typically used on low slope roofs.
Golden Pledge® – GAFMC’s strongest limited warranty for shingles. America’s strongest steep slope warranty.
Grand Sequoia® – GAFMC shingle with wood shake appearance.
Grand Slate™ – GAFMC shingle with slate appearance.
Granules – Crushed rock that is coated with a ceramic coating and fired, used as top surface on shingles.
Hand-sealing – The method to assure sealing of shingles on very steep slopes, in high wind areas, and when installing in cold weather.
High nailing – When shingles are nailed or fastened above the manufacturer’s specified nail location.
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.
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.
“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. GAFMC Timberline® Series, Country Mansion® and Grand Sequoia® Shingles. 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.
Mats – The general term for the base material of shingles and certain rolled products.
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, 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.
NRCA – The National Roofing Contractors Association. Respected national organization of roofing contractors.
Open valley – Valley installation using metal down the valley center.
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.
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.
Prevailing wind – The most common direction of wind for a particular region.
Quarter sized – Term for the size of hand sealant dabs, size of a U.S. 25¢ piece
Racking – Method of installing shingles in a straight up the roof manner.
Rake edge – The vertical edge of gable style roof planes.
Release film – The plastic sheet installed on the back of Weather Watch® and StormGuard® underlayments. Used for packaging and handling. Remove before installation.
Rigid vent – Hard plastic ridge vent material.
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.
Sawteeth – The exposed section of double thickness on Timberline® Series shingles. Shaped to imitate wood shake look on the roof.
Self-sealant – Sealant installed on shingles. After installation, heat and sun will activate sealant to seal the shingles to each other.
Selvage – The non exposed area on rolled roofing. Area without granules. Designed for nail placement and sealant.
Shed roof – Roof design of a single roof plane. Area does not tie into any other roofs.
Shingle-Mate® – GAFMC’s shingle underlayment. Breather type with fiberglass backing to reduce wrinkles and buckles.
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.
Soffit ventilation – Intake ventilation installed under the eaves, or at the roof edge.
Smart Choice® Limited Warranty – GAFMC’s standard shingle limited warranty.
Smart Choice® System Plus Limited Warranty – GAFMC’s next grade of enhanced warranty. Extended coverage for owners.
Starter strip – The first course of roofing installed. Usually trimmed from main roof material.
Steep slope roofing – Generally all slopes higher than 4/12 are considered steep slopes.
Step-flashing – Metal flashing pieces installed at side-walls and chimneys for weather-proofing.
StormGuard® – GAFMC waterproof underlayment. Film surfaced rolled underlayment, 1.5 squares coverage per roll.
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.
Timberline® Series – GAFMC’s trademark name for laminated wood shake style shingles.
TIMBERTEX® – GAFMC enhanced Hip and Ridge Shingles.
Transitions – When a roof plane ties into another roof plane that has a different pitch or slope.
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.
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 to wood decks and waterproof critical leak areas.
Weather Stopper® Integrated Roofing System™ – GAFMC’s complete roofing system and components.
Weather Watch® – GAFMC’s granule surfaced waterproof underlayment.
Woven Valleys – The method of installing valleys by laying one shingle over the other up the valley center