Roofing has its own language, and roofing lingo changes FAST. New roofing terms pop up all the time. Some roofing definitions (and acronyms) are very technical. And the stuff roofers say can sound crazy if you’re not in the know.
That’s where this roofing glossary comes in. We’ve listed the most common roofing terms and definitions used on job sites, so you never have to feel like you’re out of the loop. Our list breaks down everything from basic roofing concepts to standard materials, commercial work, install techniques, roof designs, insurance terms, roof coating types, and more.
Save this page now so you don’t need to hunt for roof terms later. Let’s talk shop.
Roofing Terms and Definitions, A-Z
A
Acrylic Coating: A water-based reflective coating commonly used on low-slope roofs. Dries flexible and UV-resistant.
ACV (Actual Cash Value): An insurance settlement method. The insurance payout reflects the depreciated value of the damaged roof.
Algae Stain: Roof discoloration caused by algae. Often misidentified as fungal growth.
Aluminized Coating: A roof coating containing aluminum particles that reflect solar energy and reduce heat transfer through the roof surface.
Application Rate: The amount of coating material applied per square foot. Expressed in gallons per square foot or mils of wet film thickness.
Architectural Metal Roofing: Metal panels designed for performance and looks. Often used on commercial or high-end residential projects for a durable finish.
ARMA: The Asphalt Roofing Manufacturers Association — a trade organization representing asphalt roofing manufacturers in North America.
ASTM International: An organization focused on 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 make self-adhering membranes stickier, and to absorb dust.
Asphalt Roofing Cement: An asphalt-based adhesive used to bond roofing materials. Also known as flashing cement or mastic. Should comply with ASTM D4586 (Asbestos-Free).
Architectural Shingles: Also known as laminated shingles. These shingles have many layers to create added thickness and visual depth.
B
Back Coating: Also see Talc. Fine mineral particles applied to shingles to prevent sticking.
Base Flashing: The part of the flashing attached to or resting on the roof deck. 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.
Bitumen: A sticky black material, used for road paving, waterproofing, and roofing. See Modified Bitumen Roofing. See also: Asphalt.
Bituminous Coating: A coating made from bitumen applied as a waterproofing layer. Often used as a base coat in built-up roofing systems.
Blistering: Bubbles that may appear on the surface of asphalt roofing after installation.
Bridging: A re-roofing method that avoids removing old shingles by spanning over them.
Built-Up Roofing (BUR): A traditional flat or low-slope roofing system consisting of multiple layers of ply sheets embedded in hot asphalt. Includes alternating layers of bitumen and reinforcing felts, topped with gravel or a cap sheet.
Bundle: A package of shingles. Most of the time, 3 bundles cover one square (100 sq. ft.) of roof. Though it can take 4 or 5 bundles, depending on the shingle type.
Butt Edge: The lower edge of the shingle tabs. Not 🍑.
C
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. Not 🍆.
Cement: See Asphalt Roofing Cement.
Chalk Line: A line made on the roof by snapping a taut string or cord dusted with chalk. Used for alignment.
Claim: A request filed to an insurance company by a homeowner to get finances for repairing a damaged roof.
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 preformed 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. 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, moist air contacts a cold surface.
Cool Roof Coating: A coating that reflects sunlight and emits absorbed heat, keeping the roof surface cooler. Classified by high solar reflectance and high thermal emittance.
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. Helps with strategy, organization, time management, efficiency, professionalism, and business growth.
Cricket: A peaked saddle construction at the back of a chimney. Prevents snow and ice from piling up, and redirects water around the chimney.
Cure Time: The period required for a roof coating to reach its full physical properties (and be fully effective) after it's been applied.
Cutout: The unobstructed sections of a strip shingle between the tabs.
D
Decking: The surface, installed over the supporting framing members, to which 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.
Depreciation: The reduction in a roof's value due to age and wear. Insurance companies calculate depreciation when settling ACV claims.
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 called a leader. Famously used as a highway by the itsy-bitsy spider.
Drip Edge Flashing: A metal strip installed along the edges of a roof to direct water away from the fascia. Corrosion-resistant, non-staining. Used along the eaves and rakes to allow water runoff and avoid water damage. Often required by building code.
Dry Film Thickness (DFT): The thickness of a coating layer after all solvents have evaporated. Quality indicator for coating systems.
E
Eave: The horizontal, lower edge of a sloped roof. Overhangs the walls of the building.
Eaves Flashing: An additional layer of roofing material applied at the eaves to help prevent damage from water backup.
Elastomeric coating: A rubber-like coating that stretches. Made to bridge minor cracks and for thermal movement. Comes in silicone, acrylic, and polyurethane.
EPDM: Ethylene Propylene Diene Monomer — a durable synthetic rubber roofing membrane often used on low-slope commercial roofs. Known for flexibility and weather resistance.
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. It’s a rough estimate of what the job will cost, but should be accurate. Roofr helps you offer free, accurate 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.
F
Facets: The individual flat planes that make up a roof. Important when measuring. More facets means more complexity.
Felt: See Underlayment.
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 Roofing Cement.
Fully Adhered System: A commercial installation where the membrane is bonded directly to the substrate with adhesive across its full surface area.
G
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. Most common pitched roof style in North America.
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. Or something the younger guys have to get their minds out of.
H
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 all four sides. Doesn’t have gables. Also just a really cool, with-it roof.
Hip Shingles: Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.
I
Ice Dam: Happens when melted snow on the overhang of a roof re-freezes, creating a barrier. Leads 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. Stops water damage caused by ice dams. 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. Can be classified as Class 1 through Class 4, with Class 4 offering the most impact resistance.
Infrared Scan: A diagnostic method (using thermal imaging) to detect moisture trapped under roofing membranes or coatings without destroying anything.
Interlocking Shingles: Individual shingles that securely connect to each other, providing enhanced wind resistance.
L
Laminated Shingles: Shingles composed of multiple layers to create added thickness. Also referred to as three-dimensional shingles or architectural shingles.
Layer: A single level or sheet of roofing material (e.g., one layer, two layers). A roof, like Shrek, has many of these.
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.
M
Mansard Roof: A type of roof with 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.
Measurement Report: See Roof Report. Or just make a free Roofr account and order your first measurement for free.
Mechanically Fastened System: A commercial membrane installation secured with fasteners and plates, typically in laps.
Membrane: A flexible, continuous layer of waterproofing material (like TPO, EPDM, or PVC), used on low-slope commercial roofs.
Mineral Stabilizers: Finely ground materials such as limestone, slate, trap rock, or other inert substances. Added to asphalt to make shingles more durable and resistant to fire and weathering.
Mineral-Surfaced Roofing: Asphalt shingles and roll roofing coated with granules for added protection.
Modified Bitumen Roofing: Asphalt-based, best for shallow roofs, popular in North America. Also known as mod bit.
Moisture Drive: Moisture vapor moving through a roofing assembly. Important when choosing a coating system for an existing roof.
N
No-Cutout Shingles: Shingles with a solid tab and no cutouts. Says what it does on the tin, I guess.
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.
O
Open Valley: A valley construction method where shingles on both sides of the valley are trimmed along chalk lines on each side. Shingles don’t extend across the valley, and the valley flashing is exposed.
Organic Felt: A base material for asphalt roofing made from cellulose fibers. These days, fiberglass-based underlayments are more commonly used instead.
OSB (Oriented Strand Board): A roof decking material made from compressed wood strands.
Overdriven Nails: Nails driven too deep into the roofing material during installation. Can damage shingles and lead to leaks.
Overhang: The extension of the roof structure beyond the exterior walls of a building.
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.
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.
P
Pallets: Wooden platforms used for storing and transporting bundles of shingles.
Parapet: A low wall around the perimeter of a flat roof. Needs special flashing at the base and along the top edge.
Peak: The highest point of a roof. Keeps roofers feeling on top of the world.
Pitch: The steepness of a roof expressed as a ratio (rise over run). A 6/12 pitch rises 6 inches for every 12 inches of horizontal run.
Polyurethane Foam (SPF): Spray foam applied directly to a roof deck. Expands to fill gaps and create a seamless insulating surface.
Ponding: The accumulation of water in low-lying areas on a roof after rainfall, which stays while other parts of the roof dry. This is usually only an issue on flat/low-slope roofs.
Primer: An asphalt-based substance used to prepare surfaces for bonding with self-adhering asphalt sheets. Or a pre-coating applied before the main coating to improve adhesion.
Proposal: AKA a quote. A contract created by a roofer for a homeowner that includes information about the roofing job they’ll do. Generally includes materials, pricing, terms and conditions, license number, insurance information, financing (if applicable), project scope and timeline, warranties, terms of payment, permits, customers information, contractor information, and spots for signatures (from both the roofer and customer).
PVC (Polyvinyl Chloride): A thermoplastic single-ply membrane known for chemical resistance and heat-weldable seams.
R
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.
RCV (Replacement Cost Value): An insurance settlement method. The payout covers the full cost to replace the damaged roof with new materials.
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.
Reflectance: Also known as Solar Reflectance Index or SRI. A measure of how much solar radiation a surface reflects. Higher reflectance = cooler roof.
Release Strip: A plastic strip applied to the back of self-sealing shingles to prevent them from sticking together in bundles. Does not need to be removed during application.
Re-roofing: 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.
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, and Material Estimate (optional).
Roofr Report: Our awesome podcast, one of the few worth listening to, featuring roofer interviews and industry topics. Not to be confused with Roof Reports.
Roofing Tape: An asphalt-saturated tape utilized with asphalt cements for flashing and patching asphalt roofing.
Run: The horizontal distance from the eaves to a point directly beneath the ridge. It is half the span.
R-Value: A measure of thermal resistance in insulation. Higher R-value = more insulating.
S
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. Used to seal gaps and provide a waterproof barrier on roofs.
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 right 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 Decking.
Shed Roof: A roof with only one sloping plane. Lacks hips, ridges, valleys, or gables.
Silicone Coating: A moisture-cure coating with good UV and ponding water resistance. Popular for low-slope commercial roof restoration.
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 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.
Staggering: A roofing application method in which shingle courses are applied vertically up the roof.
Standard Slope Application: The method of installing asphalt shingles on roof slopes ranging from 4 inches to 21 inches per foot.
Standing Seam Roof: A type of metal roof where long panels connect with raised seams that lock together. Has a sleek look and better weather protection.
Starter Strip: Asphalt roofing applied at the eave to provide additional protection under the cutouts and joints of the first shingle course.
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. Around three times as long as they are wide.
Substrate: The surface to which a coating or membrane is applied. Knowing the substrate type will tell you which primer and coating system is appropriate.
Synthetic Underlayment: An underlayment product typically made from polypropylene, and used as an alternative to felt underlayment.
T
Tab: The exposed section of strip shingles defined by cutouts.
Takeoff: Roof takeoff is another name for accurately measuring and estimating a roof before starting work. These days, it’s easiest to use fast tech tools, like Roofr’s measurement reports or Instant Estimator.
Talc: Also see Back Coating. A white powder, often added to shingles and roll roofing to add weather resistance and prevent sticking.
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.
Thermal Emittance: How well a surface releases absorbed heat. High thermal emittance keeps a roof cooler by radiating heat away.
Three-Dimensional Shingles: Also known as laminated shingles. These shingles 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.
TPO: Thermoplastic Polyolefin — a popular, energy efficient roofing system which uses a single-ply roofing membrane. Used mostly for flat roofs and in commercial roofing.
U
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.
Underdriven Nails: Nails that aren’t driven flush with the shingle surface, leaving them “proud” (sticking out). Can allow water to get in.
Underlayment: Material placed beneath roofing, such as asphalt-saturated felt or specially engineered synthetic materials, to provide extra protection for the roof deck.
Urethane Coating: A high-performance coating known for impact resistance and durability. Good for high-traffic roof areas.
V
Valley: The internal angle formed by the intersection of two sloping roof planes.
Valley Flashing: Metal flashing installed in roof valleys before shingles. Helps channel water off the roof to prevent leaks.
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.
W
Wall Flashing: A type of installation (normally metal) that is installed with masonry to divert water away from the surface and keep it dry. Stops water from pooling and creating damage or leakage on a roof.
Waste Factor: An extra percentage added to material quantities to account for cuts and trim during install. Typically 10–20%, but can vary a lot based on roof complexity and other factors.
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.
Roofing terms don’t need to be confusing
Roofing definitely has its own language, and knowing it makes the job easier. The better you are with roofing lingo, the more professional and knowledgeable you’ll look.
The best way to learn this stuff is to live it. Get on a roof. But if you’re just getting started, or in an admin role, or just need a reminder, we’ve gotcha covered. Keep this roofer’s glossary handy for the next time you need to brush up on a roof term.
And — if you want to grow your business and make your job way easier, Roofr’s your answer. From instant estimates to proposals, material orders, and a full CRM, Roofr tech lets you work faster, win more work, and keep your customers happy.