Roofing Glossary

A

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. Test and sets standards for all varieties of

of plywood 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 or bull.

 

ASTM - The American Society for Testing and Materials. Organization that sets standards for a wide variety of materials, including roofing.

 

C

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 based flashing systems.

 

Crickets - a peaked water diverter installed behind chimney and other large roof projections. Effectivley diverts water around projections.

 

Cupping - When shingles are improperly installed over an existing roof or are overexposed, they form a curl or cup.

 

E

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.

 

Exposure - The are on any roofing material that is left exposed to the elements.

 

G

Gable roof - Traditional roof style; two peaked roof planes meeting at a ridge line of equal size.

 

Granules - Crushed rock that is coated with a ceramic coating and fired, used as a top surface on shingles.

 

I

Ice Dam - When a snow load melts on roof and re-freezes at the eave areas. Ice dams force water to "back-up" a roof and cause leakage.

 

M

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.

 

O

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 - A term used for fasteners driven trough roofing material with too much force, breaking the material.

 

Over-exposed - Installing shingles courses higher than their intended exposure.

 

Q

Quater sized - Term for the size of hand sealant dabs, size of a U.S. 25¢ piece.

 

S

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 in rolled roofing. Area without granules. Designed for nail placement and sealant.

 

Shed roof - Roof design of a single roos plane. Area does not tie into any other roofs.

 

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.

 

Starter strip - The first course of roofing installed. Usually from main roof material.

 

Steep slope roofing - Generally all slopes higher than 4/12 are concidered steep slopes.

 

Step-flashing - Metal flashing pieces at side-walls and chimneys for weather-proofing.

 

U

Under-driven - Term used to describe a fastener not fully driven flush to the shingle surface.

 

Underlayments - Asphalt based rooled materials designed to be installed under main roofing material, to serve as added protection.

B

Back-surfacing - Granular material added to shingle's back to assist in keeping seperation during delivery and storage.

 

Blistering - Bubbles or pimples in roofing materials. Usually moisture related. In shingles blisters are either moister unger the material or moister trapped inside the material.

 

Blow-offs - When shingles are subject to high winds, and are forced off a roof deck.

 

Buckling - When a wrinkle or ripple affects shingles or their underlayments.

 

D

Deck - The substate over wich roofingis applied. Usually plywood, wood boards, or planks.

 

Dormer - A rasised roof extending out of a larger roof plane.

 

Drip-edge - An installed lip that keeps shingles off the deck at edges, and extends shingles out over eaves and gutters, and prevents water from backing up under shingles.

 

F

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, resilientmats 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 than plastic cement.

 

H

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.

 

L

"L" flashing - Continuous metal flashing consisting of several feet of metal. Used at horizontal walls, bent to resemble an "L".

 

Laps - The area where roll roofing or rolled underlayment overlap one another durring application (see also side laps and end laps).

 

Low slopes - Roof pitches less than 4/12 are concidered low sloped roof. Special installation practices must be used on roofs sloped 2/12-4/12.

 

N

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.

 

P

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 wing - The most common direction of wind for a particular region.

 

R

Racking - Method of installing shingles in a straight up the roof manner.

 

Rake edge - The vertical edge of gable style roof planes.

 

Ridge vent - Hard plastic vent that runs the ridge. It replaces the old style roof louvers.

 

Roof louvers - Rooftop rectangular shaped roof vents. Also called box vents, mushroom vents, airhawks, soldier vents.

 

Roof plane - A roofing are defined by havingfour seperate edges. One side of a gable, hip or mansard roof.

 

T

Tab - The bottom portion of traditional shingle seperated 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 ma show some buckles.

 

Transitions - When a roof plane ties into another roof plane that has a different pitch or slope.

 

V

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 passege of air from an enclosed space.

 

W

Warm wall - The finished wall inside of a structure, used in roofing to determine how to install waterproof underlayments at eaves.

 

Waterproof underlayments - Modified bitumen based roofing underlayments. Designed to seal 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.