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.

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 prime r– 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.


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.


or 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.

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.

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.


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.

Fiberglass mat – fibers condensed into strong, resilient mats for use in roofing materials.

– 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.

– 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”.

Laps – The area where roll roofing or rolled underlayments overlap one
another during application (see also side laps and end laps).
LEED- Leadership in Energy and Environmental Design.  An accreditation system administered by the Canadian Green Building Council to accelerate the transformation to high-performing, healthy green buildings, homes and communities throughout Canada.

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
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


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 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.

Side-lap s– The area on rolled material where one roll overlaps the rolled material beneath it. Also called selvage edge on rolled roofing.

Side-wall s
– 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 trimmed from main roof material.

Steep slope roofing – Generally all slopes higher than 4/12 are considered steep slopes.

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


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.

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.

Vapo r– 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.

Woven Valleys – The method of installing valleys by laying one shingle over the other up the valley center.

Talk to a Jay Carter Roofing Expert: 1.877.490.3400