May 30, 2023

Popular Roofing Definitions (Glossary)

Looking for a certain roofing term that you're unfamiliar with? Look no further! We've gathered a list of popular roofing definitions for you to leverage.

Time to read:
17 Minutes
Written by
Kate Robertson

Whether you're a homeowner shopping for a roof, or you're a roofing professional looking to brush up on your vocab, this is the only roofing glossary you need.

This roofing glossary is in alphabetical order.

General roofing terms to know


Algae Stain: A form of roof discoloration caused by algae. Often misidentified as fungal growth. It's also called algae discoloration.

ARMA: ARMA is the Asphalt Roofing Manufacturers Association which is a trade organization representing asphalt roofing manufacturers in North America.

ASTM International: An organization focused on the development of consensus standards, testing procedures, and specifications.

Asphalt: A bituminous waterproof material applied to roofing products during the manufacturing process.

Asphalt Primer: A thin liquid bitumen used to enhance the adhesion of self-adhering membranes and to absorb dust.

Asphalt Roofing Cement: An asphalt-based adhesive used for bonding roofing materials. Also known as flashing cement or mastic; should comply with ASTM D4586 (Asbestos-Free).

Architectural Shingles: Also known as laminated shingles, these are shingles that have multiple layers to create added thickness and visual depth.


Back Coating: Fine mineral particles are applied to the back side of shingles to prevent sticking.

Base Flashing: The part of the flashing attached to or resting on the roof deck, which directs water onto the roof covering.

Base Ply Sheet: A product designed to be the base or middle layer in a self-adhering roll roofing system for residential use.

Base Sheet: A product intended for use as the base layer in a self-adhering roll roofing system.

Blistering: Bubbles that may appear on the surface of asphalt roofing after installation.

Bridging: A re-roofing method using metric-sized shingles.

Built-Up Roofing: A flat or low-slope roof consisting of multiple layers of ply sheets embedded in hot asphalt.

Bundle: A package of shingles. Typically, there are 3, 4, or 5 bundles per 100 square feet.

Butt Edge: The lower edge of the shingle tabs.


Cap Sheet: A mineral-surfaced material used either on its own or as the top layer of a multi-layer rolled roof covering system.

Caulk: To seal a joint with mastic or asphalt cement to prevent leaks.

Cement: Also known as asphalt roof 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" Fire Rating: The highest fire test classification for roofing as per ASTM E108 or UL790, indicating that the roofing can withstand severe exposure to external fire sources.

Class "B" Fire Rating: A fire test classification indicating that the roofing material can withstand moderate exposure to external fire sources.

Class "C" Fire Rating: A fire test classification indicating that the roofing material can withstand light exposure to external fire sources.

Class 4 Impact Resistance: The highest impact resistance classification according to the UL 2218 Impact test, indicating that shingles are highly resistant to hailstorm impacts.

Closed Cut Valley: A valley treatment method where one side of the valley has shingles extending across it, while the other side has shingles trimmed 2" from the valley centerline. The valley flashing is not visible.

Collar: A pre-formed flange placed over a vent pipe to seal the roof around the opening. Also called a vent sleeve.

Concealed Nail Method: A roll roofing application method where 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 conversion of water vapor into liquid when warm, moisture-laden air contacts a cold surface.

Counter Flashing: The part of the flashing attached to a vertical surface to prevent water from seeping behind the base flashing.

Course: A row of shingles or roll roofing running horizontally along the roof.

Coverage: The number of layers of material between the exposed surface of the roofing and the deck; for example, single layer, dual layer, etc.

CRM (Customer Relationship Management): A software that allows roofers to manage their jobs, leads, customers, communications, timelines, and pipelines in one place.

Cricket: A peaked saddle construction at the back of a chimney to prevent the accumulation of snow and ice and redirect water around the chimney.

Cutout: The unobstructed sections of a strip shingle between the tabs.


Decking: The surface, installed over the supporting framing members, to which the roofing is applied. The minimum thickness of a wood decking is a 15/32” exterior grade plywood or 7/16” exterior grade OSB or as required by local building codes.

Dormer: A framed window unit projecting through the sloping plane of a roof.

Double Layer: Application of asphalt roofing in such a way that the overlapped portion is at least 2” 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 referred to as a leader.

Drip Edge: A corrosion-resistant, non-staining material used along the eaves and rakes to allow water run-off to drip clear of underlying construction.


Eaves: The horizontal, lower edge of a sloped roof.

Eaves Flashing: An additional layer of roofing material applied at the eaves to help prevent damage from water backup.

Estimate: A general estimate of the cost to perform a roofing job from start to finish. This generally includes materials, labor, and a profit margin. This should be a rough estimate of what the job will cost, but should be accurate.

Estimates allow homeowners to consider multiple bids. Roofr allows you to offer free estimates for homeowners in minutes with our Instant Estimator.

Exposed Nail Method: Application of roll roofing where all nails are driven into the cemented, overlapping course of roofing. Nails are exposed to the weather.

Exposure: That portion of the roofing exposed to the elements after installation.


Fiberglass Mat: The central material in an asphalt roofing shingle manufactured from glass fibers.

Flashing: Pieces of metal used to prevent water seepage into a building around any intersection or projection on a roof, such as vent pipes, chimneys, adjoining walls, dormers, and valleys. Galvanized metal flashing should be a minimum of 26-gauge.

Flashing cement: See Asphalt Roof Cement.


Gable: The upper triangular portion of a sidewall that comes to a point at the ridge of a double-sloping roof.

Gable Roof: A simple two-sided roof above a gable.

Gambrel Roof: A type of roof containing two sloping planes of different pitches on each side of the ridge. The lower plane has a steeper slope than the upper and contains a gable at each end.

Granules: Usually 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.


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-layer portion of the top lap of strip shingles.

Hexagonal Shingles: Shingles that have a hexagon-like appearance after installation.

Hip: The inclined external angle formed by the intersection of two sloping roof planes. Extends from the ridge to the eaves.

Hip Roof: A type of roof containing sloping planes on each of four sides. It does not have gables.

Hip Shingles: Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.


Ice Dam: A phenomenon that occurs when melted snow on the overhang of a roof refreezes, creating a barrier. This can lead to water being forced up and under shingles, resulting in leaks.

Ice Dam Protection: The installation of one or more layers of self-adhering underlayment at the eaves of a building to prevent water damage caused by ice dams. It is also known as "Eave Flashing."

Ice & Water Shield: A waterproof roof underlayment membrane created to protect vulnerable areas on a roof from ice and water damage. Ice and water shields (sometimes called ice and snow shields up north) are created with polymer-modified bitumen.

Impact Resistant Shingles: Shingles designed to withstand damage from hailstorms. These shingles undergo testing and classification according to UL 2218 standards and can be classified as Class 1 through Class 4, with Class 4 offering the highest level of impact resistance.

Interlocking Shingles: Individual shingles that securely connect to each other, providing enhanced wind resistance.


Layer: A single level or sheet of roofing material (e.g., one layer, two layers).

Laminated Shingles: Shingles that are composed of multiple layers to create added thickness. They are also referred to as three-dimensional shingles or architectural shingles.

Low Slope Application: The method of installing asphalt shingles and underlayment on roof slopes ranging from 2 inches to less than 4 inches per foot.


Mansard Roof: A type of roof characterized by two sloping planes with different pitches on each of its four sides. The lower plane has a steeper pitch than the upper, often approaching vertical.

Mineral Stabilizers: Finely ground materials such as limestone, slate, trap rock, or other inert substances added to asphalt in shingles to enhance durability and resistance to fire and weathering.

Mineral-Surfaced Roofing: Asphalt shingles and roll roofing coated with granules for added protection.


No-Cutout Shingles: Shingles with a solid tab and no cutouts.

Non-Veneer Panel: A wood-based panel without a laminated veneer that carries an APA span rating, such as wafer board or oriented strand board.


Open Valley: A valley construction method where shingles on both sides of the valley are trimmed along chalk lines on each side. Shingles do not extend across the valley, and the valley flashing is exposed.

Organic Felt: A base material for asphalt roofing made from cellulose fibers.

Overhang: The extension of the roof structure beyond the exterior walls of a building.

Overlay: A re-roofing method where new asphalt shingles are installed over existing shingles, with the top edge of the new shingle butted against the bottom edge of the existing shingle tab.

Overlap: The act of covering one shingle or roll with another to create a layered surface.

Overlap Cement: An asphalt-based cement (conforming to ASTM D3019) used to bond overlapping layers of roll roofing.


Proposal (or Quote): A contract created by a roofer for their lead/homeowner that includes information about the job they will perform on their roof. This generally includes materials, pricing, terms & conditions, license number, insurance information, financing (optional), project scope and timeline, warranties, terms of payment, permits, customers information, contractor information, and signatures (both the roofer and customer).

Pallets: Wooden platforms used for storing and transporting bundles of shingles.

Ponding: The accumulation of water in low-lying areas on a roof after rainfall, which persists while other parts of the roof dry.

Primer: An asphalt-based substance used to prepare surfaces for bonding with self-adhering asphalt sheets.


Rafter: The supporting framing member positioned beneath the deck, sloping from the ridge to the wall plate.

Rake: The sloped edge of a roof that extends over a wall.

Random-Tab Shingles: Shingles with varying tab sizes and exposures.

Recovering: The process of installing an additional layer of roofing over an existing layer. Building codes typically allow a maximum of two layers of any roofing type on a roof.

Release Strip: A plastic strip applied to the back of self-sealing shingles to prevent them from sticking together in bundles. It does not need to be removed during application.

Reroofing: The procedure of removing the existing roof coverings and replacing them with a new roofing system.

Ridge: The highest horizontal angle formed by the intersection of two sloping roof planes.

Ridge Shingles: Shingles used to cover the horizontal angle formed by the meeting of two sloping roof planes.

Rise: The vertical distance from the eaves line to the ridge.

Roll Roofing: Asphalt roofing products manufactured in roll form.

Roofing Tape: An asphalt-saturated tape utilized with asphalt cements for flashing and patching asphalt roofing.

Roof Report: A digital roof measurement report that includes all the measurements of a residential or commercial roof including: Image, Length Measurement Report, Area Measurement Report, Pitch & Direction Measurement Report, All Structures Summary, Material Estimate (optional). These are generally used to avoid having to hand measure a roof. .

Run: The horizontal distance from the eaves to a point directly beneath the ridge. It is half the span.


Saturated Felt: An asphalt-impregnated felt used as an underlayment between the deck and the roofing material.

SBS: Styrene-Butadiene-Styrene, a synthetic polymer mixed with asphalt in some products to enhance flexibility and other qualities.

Sealant: Also known as Asphalt Roof Cement, it is used to seal gaps and provide a waterproof barrier on roofs.

Shading: Slight variations in shingle color resulting from normal manufacturing operations.

Self-Adhering Shingle Underlayment: A waterproofing underlayment designed to protect against water infiltration caused by ice dams or wind-driven rain. It must meet ASTM D1970 standards and bear the corresponding label.

Self-Sealing Shingles: Shingles with factory-applied strips or spots of adhesive for bonding shingle courses together.

Self-Sealing Strip or Spot: Factory-applied adhesive that bonds shingle courses when exposed to sunlight heat after installation.

Selvage: The portion of roll roofing overlapped by the succeeding course to achieve single or double coverage at the lap.

Shading: Slight variations in shingle color resulting from normal manufacturing operations.

Sheathing: See Deck.

Shed Roof: A roof with only one sloping plane, lacking hips, ridges, valleys, or gables.

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 inches. For example, a roof slope of 4/12 means there is a 4-inch rise every 12 inches.

Smooth-Surfaced Roofing: Roll roofing coated with ground talc or mica instead of granules.

Soffit: The finished underside of the eaves.

Soil Stack: A vent pipe that extends through the roof.

Span: The horizontal distance between eaves.

Square: A unit of roof measurement covering an area of 100 square feet.

Square-Tab Shingles: Shingles with uniform tab size and exposure.

Standard Slope Application: The method of installing asphalt shingles on roof slopes ranging from 4 inches to 21 inches per foot.

Starter Strip: Asphalt roofing applied at the eave to provide additional protection under the cutouts and joints of the first shingle course.

Staggering: A roofing application method in which shingle courses are applied vertically up the roof.

Steep Slope Application: The method of installing asphalt shingles on roof slopes greater than 21 inches per foot.

Step Flashing: The method of applying base flashing where a vertical surface meets a sloping roof plane.

Strip Shingles: Asphalt shingles made from a single layer, approximately three times as long as they are wide.

Synthetic Underlayment: An underlayment product typically made from polypropylene and used as an alternative to felt underlayment.


Tab: The exposed section of strip shingles defined by cutouts.

Talc: Refer to Back Surfacing.

Tear Off: The process of completely removing an existing roofing system down to the structural deck.

Telegraphing: A distortion that can occur in shingles when a new roof is installed over an uneven surface, causing the imperfections of the underlying surface to be visible.

Three-Dimensional Shingles: Also known as laminated shingles, these are shingles that have multiple layers to create extra thickness and a textured appearance.

Top Lap: The section of roofing covered by the next course of shingles after installation.


UL: Abbreviation for Underwriters Laboratories, LLC, an independent organization that tests and certifies products for safety and performance.

UL Label: A label affixed to packaging indicating the level of fire and/or wind resistance of asphalt roofing.

Underlayment: Material placed beneath roofing, such as asphalt-saturated felt or specially engineered synthetic materials, to provide additional protection for the roof deck.


Valley: The internal angle formed by the intersection of two sloping roof planes.

Vapor Retarder: Any material used to prevent the passage of water vapor.

Vent: An opening or outlet, such as a pipe or stack, that protrudes through the roof deck. It can also refer to devices installed on the roof, gable, or soffit for the purpose of ventilating the underside of the roof deck.

Vent Sleeve: See Collar.


Wall Flashing: A type of installation (normally metal) that is installed with masonry to divert water away from the surface and keep it dry to prevent water from pooling and creating damage or leakage on a roof.

Woven Valley: A method of constructing valleys where shingles from both sides of the valley extend across the valley and are overlapped and interwoven with alternating courses. The valley flashing is not exposed.

Join Roofr, get a free roof measurement report
Get started

Want the latest roofing tips & tricks?

Be the first to know the best roofing & business tips, and discover more efficient ways to grow your business. Subscribe to our newsletter to stay up to date (and ahead of your competition).
Thanks for subscribing! You'll be the first to receive new updates.
Oops! Something went wrong while submitting the form.

Leave a comment...

Join thousands of roofers who successfully streamline their sales process with Roofr

Get started for free
a close up view of a metal roof