Glossary of Roofing Terms

A

Algae discoloration
A type of roof discoloration caused by algae, also called fungus growth.
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 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 shingle
a shingle manufactured by coating a reinforcing material (felt or fibrous glass mat) with asphalt and having mineral granules on the side exposed to the weather.
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.

B

Back-surfacing
Granular material added to shingle's back to assist in keeping separate during delivery and storage.
Balanced system
A 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 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 in roofing materials, usually caused by trapped moisture.
Blow-offs
When shingles are blown off a roof deck by high winds.
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.

C

Caulk
To fill a joint with mastic or asphalt cement to prevent leaks.
Cement
See Asphalt plastic roofing cement.
Chalk line
A 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 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 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 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 EstatesTM
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.

D

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.
Downspout
A pipe for draining water from roof gutters. Also called a leader.
Drip-edge
An installed lip that 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.

E

Eaves
The roof edge from the fascia to the structure's outside wall.
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 area on any roofing material that is left exposed to the elements.

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, which sets national construction standards.
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.

G

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 Manor
Highest end Composite roofing shingle to look like a slate roof.
Grand Sequoia®
GAFMC shingle with wood shake appearance.
Grand SlateTM
GAFMC shingle with slate appearance.
Granules
Crushed rock that is coated with a ceramic coating and fired, used as top surface on shingles.

H

Hand-sealing
The method to assure 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 type of roof containing sloping planes of the same pitch on each of four sides. Contains no gables.
Hip shingles
Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.

I

Ice Dam
When a snow load melts on a roof and re-freezes at the eave areas, causing distortion and leaks. For an illustration please click here.

L

"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.
Landmark
30 year shingle offered by Certainteed laminated roofing shingle
Landmark Solaris
IR forms a barrier between your roof and the sun that reduces your roof's temperature by as much as 20 percent in the summer.
Landmark TL
An impact resistant version of our dramatically thick luxury shingle offers you the distinct look of natural wood shakes, not to mention a lifetime warranty. Made of three laminated layers of the industry''s strongest roofing materials, it''s dimensional in appearance and unparalled in durability.
Landmark Preimium
life time shingle offered by Certainteed, laminated roofing shingle
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.

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 to bond a chimney's bricks together.
Mountain Ridge
high-profile hip and ridge accessory is the perfect finishing touch for your roof with blended color and high-profile design. The difference is noticeable...by blending in.

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 and sits up off the roof deck.
Nesting
Installing a second layer of shingles aligning courses with the original roof to avoid shingle cupping.
Net free area
Area unobstructed by screens, louvers or other materials.
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.

O

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
Fasteners which have been driven too far into roofing 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.

P

Pitch
The ratio of the rise of the roof to the span of the roof.
Power vents
Electric fans used to move air from attics and structures.
Plastic cement
Asphalt based sealant. Also called bull, mastic, tar, or asphalt cement.
Plumbing vents
Plumbing pipes that project through a roof plane. Also called vent stacks.
Presidential Shake shingles
deliver the charm and character of hand-split wood shakes with the durability and strength that presides over wood in virtually every surrounding.
Prevailing wind
The most common direction of wind for a particular region.

Q

Quarter sized
Term for the size of hand sealant dabs, size of a U.S. 25ยข piece.

R

Racking
Method of installing shingles in a straight up the roof manner.
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 protective plastic sheet on the back of Weather Watch® and StormGuard® underlayments.
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.
Rigid vent
Hard plastic ridge vent material.
Roof louvers
Rooftop rectangular shaped roof vents.
Roof plane
A roofing area defined by having four separate edges. One side of a gable, hip or mansard roof.
Roofers Select
As a final layer of protection, this high-performance underlayment covers the entire roof after the WinterGuardTM application. It's reinforced with fiber glass to provide extra resistance to wrinkling and tear out from fasteners.

S

Sawteeth
The exposed section of double thickness on Timberline® Series shingles. Gives a wood shake effect.
Self-sealant
Sealant pre-applied to shingles which will, with heat, seal the shingles together.
Selvage
The unexposed area on rolled roofing, designed for nail placement and sealant.
Shadow RidgeTM
Hip and Ridge Accessory Shingles are designed specifically for use with LandmarkTM TL, Landmark Series, Independence, Classic Horizon and New Horizon shingles and are used to finish the hips and ridges of your roof.
Shed roof
A flat roof unconnected to any other roofs.
Shingle-Mate®
GAFMC's shingle underlayment with fiberglass backing to reduce wrinkles and buckles.
Side-laps
The area on rolled material where one roll overlaps the rolled material beneath it.
Side-walls
Where a vertical roof plane meets a vertical wall.
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 enhanced warranty, offering extended coverage for homeowners.
Soffit
The finished underside of the eaves.
Starter strip
The first course of roofing installed.
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 film surfaced waterproof underlayment.
Swiftstart
metric starter shingle is designed specifically for use with CertainTeed Landmark Series shingles.

T

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 have been placed over a buckled or uneven surface and show it.
Timberline® Series
GAFMC's trademark name for laminated wood shake style shingles.
TIMBERTEX®
GAFMC enhanced Hip and Ridge Shingles.
Transitions
A point where two roof planes with different slopes meet.

U

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
A fastener which hasn't been driven entirely to the shingles surface.
Undereave
Underside area of the overhang at the eave of the roof.
Underlayments
Asphalt based rolled materials installed under main roofing for added protection.

V

Valleys
Where two sloped roof planes join in a "V."
Vapor
Water in the form of a gas.
Ventilation
Openings allowing the passage of air from an enclosed space.

W

Warm wall
The finished wall inside of a building.
Warranty
A written promise to the homeowner.
Waterproof underlayments
Modified bitumen based roofing underlayments that waterproof critical leak areas.
Weather Stopper® Integrated Roofing SystemTM
GAFMC's complete roofing system and components.
Weather Watch®
GAFMC's granule surfaced waterproof underlayment.
WinterGuardTM waterproofing shingle underlayment
is the solution for winning the battle against water penetration in your roof's most vulnerable places. WinterGuard is a composite material of asphalt polymers, formed into a rolled sheet. The asphalt makes it vapor-tight, and the polymers make the asphalt elastic and sticky. This protective barrier is able to stretch and seal around nails driven through it.
Woven Valleys
A way of installing valleys by laying one shingle over another up the valley center.

X

XT-25
3 tab roof

© 2010 Bill West roofing, Inc. / Design + Code: Tom Hapgood / Words: Rebecca Haden / KC pic: calebdzahnd / Roofer pic: Editor B