The first step to knowing your way around your roof is to understand its parts and terminology.

Algae discoloration: A type of roof discoloration caused by algae. Commonly called fungus growth.

American method: Application of giant individual shingles with the long dimension parallel to the rake. Shingles are applied with a 3/4-inch space between adjacent shingles in a course.

ASTM: American Society for Testing and Materials. A voluntary organization concerned with development of consensus standards, testing procedures and specifications.

Asphalt: A bituminous waterproofing agent applied to roofing materials during manufacturing.

Asphalt plastic roofing cement: An asphalt-based cement used to bond roofing materials. Also known as flashing cement or mastic; should conform to ASTM D-4586.

Back Surfacing: Fine mineral matter applied to the back side of shingles to keep them from sticking.

Base flashing: That portion of the flashing attached to or resting on the deck to direct the flow of water onto the roof covering.

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

Brands: Airborne burning embers released from a fire.

Bridging: A method of reroofing with metric-sized shingles.

Built-up roof: A flat or low-sloped roof consisting of multiple layers of asphalt and ply sheets.

Bundle: A package of shingles. There are 3, 4 or 5 bundles per square.

Butt edge: The lower edge of the shingle tabs.

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 method of valley treatment in which shingles from one side of the valley extend across the valley while shingles from the other side are trimmed two inches from the valley centerline. The valley flashing is not exposed. Coating: A layer of viscous asphalt applied to the base material into which granules or other surfacing is embedded.

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

Concealed nail method: Application of roll roofing in which 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 change of water from vapor to liquid when warm, moisture-laden air comes in contact with a cold surface. Counter flashing: That portion of the flashing attached to a vertical surface to prevent water from migrating behind the base flashing.

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

Coverage: Amount of weather protection provided by the roofing material. Depends on number of layers of material between the exposed surface of the roofing and the deck; i.e., single coverage, double coverage, etc.

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

Cutout: The open portions of a strip shingle between the tabs. Deck: The surface installed over the supporting framing members to which the roofing is applied.

Dormer: A framed window unit projecting through the sloping plane of a roof. Double coverage: Application of asphalt roofing such that the lapped portion is at least two inches 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.

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

Dutch lap method: Application of giant individual shingles with the long dimension parallel to the eaves. Shingles are applied to overlap adjacent shingles in each course as well as the course below.

Eaves: The horizontal, lower edge of a sloped roof. Eaves flashing: Additional layer of roofing material applied at the eaves to help prevent damage from water back-up.

Edging strips: Boards nailed along eaves and rakes after cutting back existing wood shingles to provide secure edges for reroofing with asphalt shingles.

Ell: An extension of a building at right angles to its length.

Exposed nail method: Application of roll roofing in which all nails are driven into the cemented, overlapping course of roofing. Nails are exposed to the weather.

Exposure I grade plywood: Type of plywood approved by the American Plywood Association for exterior use.

Feathering strips: Tapered wood filler strips placed along the butts of old wood shingles to create a level surface when reroofing over existing wood shingle roofs. Also called horsefeathers.

Felt: Fibrous material saturated with asphalt and used as an underlayment or sheathing paper.

Fiber glass mat: An asphalt roofing base material manufactured from glass fibers.

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

Flashing Cement: See asphalt plastic roofing cement.

FM: Factory Mutual Research Corp.

Free-tab shingles: Shingles that do not contain factory-applied strips or spots of self-sealing adhesive.

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

Gable roof: A type of roof containing sloping planes of the same pitch on each side of the ridge. Contains a gable at each end.

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

Granules: 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 coverage portion of the top lap of strip shingles. HEX shingles: Shingles that have the appearance of a hexagon after installation.

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

Horsefeathers: See feathering strips.

Ice dam: Condition formed at the lower roof edge by the thawing and re-freezing of melted snow on the overhang. Can force water up and under shingles, causing leaks.

Interlocking shingles: Individual shingles that mechanically fasten to each other to provide wind resistance.

Laminated shingles: Strip shingles containing more than one layer of tabs to create extra thickness. Also called three-dimensional shingles.

Lap: To cover the surface of one shingle or roll with another.

Lap cement: An asphalt-based cement used to adhere overlapping plies of roll roofing.

Low slope application: Method of installing asphalt shingles on roof slopes between two and four inches per foot.

Mansard roof: A type of roof containing two sloping planes of different pitch on each of four sides. The lower plane has a much steeper pitch than the upper, often approaching vertical. Contains no gables.

Masonry primer: An asphalt-based primer used to prepare masonry surfaces for bonding with other asphalt products.

Mastic: See asphalt plastic roofing cement.

Mineral stabilizers: Finely ground limestone, slate, traprock or other inert materials added to asphalt coatings for durability and increased resistance to fire and weathering.

Mineral-surfaced roofing: Asphalt shingles and roll roofing that are covered with granules.

Nesting: A method of reroofing with new asphalt shingles over old shingles in which the top edge of the new shingle is butted against the bottom edge of the existing shingle tab.

No-cutout shingles: Shingles consisting of a single, solid tab with no cutouts.

Non-veneer panel: Any wood based panel that does not contain veneer and carries an APA span rating, such as wafer board or oriented strand board.

Normal slope application: Method of installing asphalt shingles on roof slopes between 4 inches and 21 inches per foot.

Open valley: Method of valley construction in which shingles on both sides of the valley are trimmed along a chalk line snapped on each side of the valley. Shingles do not extend across the valley. Valley flashing is exposed.

Organic felt: An asphalt roofing base material manufactured from cellulose fibers.

Overhang: That portion of the roof structure that extends beyond the exterior walls of a building. Pallets: Wooden platforms used for storing and shipping bundles of shingles.

Pitch: The degree of roof incline expressed as the ratio of the rise, in feet, to the span, in feet.

Plastic Cement: A compound used to seal flashings and in some cases to seal down shingles as well as for other small waterproofing jobs. Where plastic cement is required for sealing down shingles, use a dab about the size of a quarter unless otherwise specified.

Ply: The number of layers of roofing: i.e. one-ply, two-ply.

Quick-setting cement: An asphalt-based cement used to adhere tabs of strip shingles to the course below. Also used to adhere roll roofing laps applied by the concealed nail method.

Racking: Roofing application method in which shingle courses are applied vertically up the roof rather than across and up. Not a recommended procedure.

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

Rake: The inclined edge of a sloped roof over a wall from the eave to the ridge.

Random-tab shingles: Shingles on which tabs vary in size and exposure.

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.

Ridge: The uppermost, horizontal external angle formed by the intersection of two sloping roof planes.

Ridge shingles: Shingles used to cover the horizontal external angle formed by the intersection 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 used with asphalt cements for flashing and patching asphalt roofing.

Run: The horizontal distance from the eaves to a point directly under the ridge. One half the span.

Saturant: Asphalt used to impregnate an organic felt base material.

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

Self-sealing cement: A thermal-sealing tab cement built into the shingle to firmly cement the shingles together automatically after they have been applied properly and exposed to warm sun temperatures. In warm seasons, the seal will be complete in a matter of days. In colder seasons, sealing time depends on the temperature and amount of direct sunlight hitting the shingles. Hand sealing with plastic cement should be done to ensure sealing in winter.

Self-sealing shingles: Shingles containing factory-applied strips or spots of self-sealing adhesive.

Self-sealing strip or spot: Factory-applied adhesive that bonds shingle courses together when exposed to the heat of the sun after application.

Selvage: That portion of roll roofing overlapped by the succeeding course to obtain double coverage.

Shading: Slight differences in shingle color that may occur as a result of normal manufacturing operations. Sheathing: Exterior grade boards used as a roof deck material.

Shed roof: A roof containing only one sloping plane. Has no 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 feet.

Smooth-surfaced roofing: Roll roofing that is covered with ground talc or mica instead of granules (coated).

Soffit: The finished underside of the eaves. Soil stack: A vent pipe that penetrates the roof.

Span: The horizontal distance from eaves to eaves.

Specialty eaves flashing membrane: A self-adhering, waterproofing shingle underlayment designed to protect against water infiltration due to ice dams or wind driven rain.

Square: A unit of roof measure covering 100 square feet.

Square-tab shingles: Shingles on which tabs are all the same size and exposure. Starter strip: Asphalt roofing applied at the eaves that provides protection by filling in the spaces under the cutouts and joints of the first course of shingles.

Steep slope application: Method of installing asphalt shingles on roof slopes greater than 21 inches per foot.

Step flashing: Flashing application method used where a vertical surface meets a sloping roof plane.

Strip shingles: Asphalt shingles that are approximately three times as long as they are wide.

Tab: The exposed portion of strip shingles defined by cutouts. Talc: See back surfacing. Telegraphing: A shingle distortion that may arise when a new roof is applied over an uneven surface.

Three-dimensional shingles: See laminated shingles.

Three-tab shingle: The most popular type of asphalt shingle usually 12" x 36" in size with three tabs. Top lap: That portion of the roofing covered by the succeeding course after installation.

UL: Underwriters Laboratories, Inc.

UL label: Label displayed on packaging to indicate the level of fire and/or wind resistance of asphalt roofing. Underlayment: A layer of asphalt saturated (sometimes referred to as tar paper) which is laid down on a bare deck before shingles are installed to provide additional protection for the deck.

Valley: The internal angle formed by the intersection of two sloping roof planes to provide water runoff.

Vapor retarder: Any material used to prevent the passage of water vapor. Vent: Any outlet for air that protrudes through the roof deck such as a pipe or stack. Any device installed on the roof, gable or soffit for the purpose of ventilating the underside of the roof deck.

Vent sleeve: See collar.

Woven Valley: Method of valley construction in which shingles from both sides of the valley extend across the valley and are woven together by overlapping alternate courses as they are applied. The valley flashing is not exposed.


Single Ply Roofing systems manufacturers
(Elastomeric and Thermoplastic)



Welcome to BondCote: Corporation
In 1949, BondCote was founded on two principles: Produce great products. Keep our promises. Over 50 years later, we're still covering the world with the very best coated and laminated fabrics for the single-ply roofing, transportation, military, environmental, medical, agricultural, recreational, and athletic industries. Superior products are impossible without superior people behind them, and that is the secret to our success. We are dedicated to providing unparalleled quality and service. Stock orders are shipped within 24 hours. The R&D, technical, and inspection departments of BondCote are unsurpassed because they are a reflection of the men and women who work here. With a half century of experience and millions of square yards manufactured, we are ready and able to respond to your needs. BondCote stands behind our promises.


Carlisle: SynTec Systems
For more than 40 years, Carlisle SynTec has provided dependable, longest-lasting products to the low-slope commercial roofing industry. Carlisle offers a variety of EPDM, TPO, PVC and FleeceBACK membranes that offer long-term performance in any climate. Carlisle also offers a full line of roof garden systems and energy-saving polyisocyanurate insulation to complement any membrane installation.


Dow: Roofing Systems
Heat-weldable, reinforced membranes-Stevens EP™ (TPO); Stevens EV® (Elvaloy®); and Stevens CSPE (made with Hypalon® from DuPont) Roofing Systems. Dow Roofing Systems have several attachment options, mechanically attached, fully adhered, Steve EP and EV Fleece adhered, ballasted, Stevens EP Metal Retrofit, Stevens Profile and Stevens GardenTop™. Membranes are available in white and colors.


Duro-Last: Roofing
Since 1978, Duro-Last Roofing has manufactured a custom-fabricated single-ply roofing system that is ideal for any commercial or industrial (flat or low-sloped) application. Extremely durable and easily installed without disruption to daily operations, the Duro-Last Roofing System is also leak-proof, energy-efficient, resistant to high winds, and virtually maintenance-free.

Why Select FiberTite®: Roofing Membranes Over Other Roofing Products?

FiberTite is a unique DuPont™: Elvaloy® (Ketone Ethylene Ester - KEE) based roofing system that was invented over a quarter century ago. Today, over 99% of FiberTite roofs ever installed are still performing. Our success can be summarized by four facts: FiberTite roofing membranes start with the industry’s heaviest base fabric. Add to that our proprietary knit design, and you’ve got roofing systems with superior puncture and tear resistance. FiberTite's proprietary formula includes the industry's highest KEE content, allowing our roofing membranes to maintain excellent flexibility, as well as chemical and UV resistance. FiberTite was invented and is manufactured by Seaman Corporation, a recognized world



Firestone: Building Products Company was founded in 1980 on the cornerstone of quality and continues to build upon that philosophy today. For nearly 30 years, contractors, building owners, and specifiers have trusted Firestone Building Products Company as the leading, single source for superior commercial roofing solutions. Firestone’s comprehensive line of commercial roofing products includes single-ply EPDM and TPO, asphalt roofing membranes, metal roofing systems, polyiso insulation, and accessories for commercial roofing applications. Firestone’s wide range of roofing system options covers billions of square feet of building space – from commercial offices, manufacturing sites and warehouses to retail centers, educational facilities and more. As part of the company’s commitment to environmental solutions, Firestone offers product choices such as garden roofing systems, white UltraPly™ TPO, energy-saving ISO 95+™ polyiso insulation, reflective white AcryliTop™ coatings, and Firestone CoverDeck made from 54 percent recycled content. Quality products, quality installation expertise and quality warranties backed by the assets of a diversified multibillion-dollar corporation make it clear why “Nobody Covers You Better” than Firestone Building Products.


Flex Roofing: Systems
Offers a complete line of Thermoplastic Elvaloy/PVC and TPO Single-Ply and Multi Ply Roofing and Waterproofing Systems. For more than 20 years, Flex has provided thermoplastic membranes to the commercial, industrial and residential markets, ranging from mechanically attached to fully adhered, along with green roof and solar roof systems.


Superior: Low-Slope Solutions
Unbiased Approach - Unlike some roofing manufacturers who seem to have a “one-technology-fits-all” mentality, our goal is to help you match the right roofing technology to your specific needs. We can do this because we offer all major low-slope roofing technologies, including repair and maintenance products, roof restoration systems (often at up to half the cost of a new roof), as well as new roofing systems (BUR, MB, TPO, PVC, and composite systems). Special & Unique Guarantees - Including Well Roof Advantage (extends a low slope roof guarantee by up to 25% for free, as long as regular maintenance is performed) and the All-American Pledge Guarantee (the first NDL guarantee that covers both low and steep slope roofs on a single property) Energy Smart - Some of these roofing options even have the ENERGY STAR™ and/or CRRC ratings, to take advantage of the growing interest in energy-saving, white reflective roofing.



GenFlex: Roofing Systemsis a leading, full-line supplier of high quality single-ply roofing products for the commercial market. Headquartered in Indianapolis, IN, GenFlex manufactures, markets, and sells its products through a network of distributors, sales agents, and authorized commercial roofing contractors. GenFlex entered the single-ply commercial roofing industry in 1980, utilizing the company's 80+ years as a world leader in the development of polymer and chemical technology. The company offers EPDM, TPO (thermoplastic polyolefin), polyisocyanurate insulation, fasteners, and a complete line of related installation accessories.


IB: Roof Systems
has set the standard with the highest quality systems. Featuring our CPA single-ply membrane ranging from mechanically attached, fully adhered and our new wind ballast system. Plus a full architectural section (Specifications, details, project profiles, etc).


Johns Manville: Johns Manville Roofing Systems has an extensive offering of low slope roofing solutions, including a complete line of single-ply, built-up and modified-bitumen membranes, including Cool Roof solutions. They are complemented by quality thermal insulations, cover boards, adhesives, cements, roof coatings and specialty roofing products as well as technical services and strong guarantees.


Marathon Roofing Products
Manufacturer of roofing accessories for commercial and industrial roofing; specializing in roof drains and vents in copper, aluminum, cast iron, stainless steel and durable plastic. The company additionally offers a wide range of roofing equipment and safety materials. New products include a paver support pedestal system.


Mule-Hide: Products Co.
Mule-Hide offers a broad line of premium quality low-slope, sustainable roofing systems, including EPDM, TPO, PVC, and walkable PVC. Quality control, training, and technical support second to none. Time-proven systems with extensive standard system, premium system, and membrane warranties. Mule-Hide – The name trusted in roofing since 1906.


Sika Sarnafil: Sika Sarnafil is an international supplier of high-quality, thermoplastic roofing and waterproofing membranes. We have a wide range of roofing solutions including green roofs and solar integrated roofing, as well as solutions that simulate a metal roof. Our highly reflective membrane meets the cool roof standards of EnergyStar®, Title 24, LEED® and Green Globes®.



Since 1908, SOPREMA: has been a world-wide leader in the roofing membrane industry. Here in the Unites States, SOPREMA has transformed into “The Building Envelope Company” with waterproofing products for every area of the building envelope. SOPREMA offers a wide range of products including SBS modified bitumen roofing membranes, liquid applied systems, waterproofing products for the entire building envelope, a complete line of self-adhered products, green solutions such as garden roof, building integrated photovoltaic systems and much more.


Tremco Roofing
Tremco has been a leading roofing manufacturer for over 75 years and offers over 160 different types of roof systems including cold and hot applied built-up, modified bitumen, single ply, and metal roof/wall systems. Our highly-accredited Architectural Specialists are your educational resource and will provide you with specification assistance to help you achieve optimum results.


WeatherBond: also offers a complete line of fully-adhered and mechanically-attached TPO Roofing Systems. TPO is the fastest growing membrane in the single-ply roofing industry. Extreme durability and puncture resistance makes TPO membrane an excellent choice for any size roof, large or small.


Versico: has a wide range of single-ply roofing systems to meet almost any building design, from our EPDM line of Versigard Roofing Systems, to our state-of-the-art, thermoplastic line of heat-weldable Versiweld Premier Roofing Systems.
Major Shingles Manufacturers

Four large domestic manufacturers dominate the North American market for asphalt shingles, GAF Material Corporation and CertainTeed have the majority of the market with Owens Corning, and Tamko Building Products splitting a smaller share.

GAF: I can hardly recommend the GAF website as it consistently hangs up my computer. GAF manufactures its own line of shingles and also manufactures under the ELK name, a Canadian manufacturer it purchased. It is well known among homeowners, is very competitively priced and offers extensive support programs to assist contractors in selling its products. Site has product specifications under two sections - material for homeowners and material for contractors/suppliers.

CertainTeed: Roofing provides material for builders and contractors based on their location - since product availability varies by region. Shows small color swatches and price legends for a wide range of steep slope roof products including its full line of asphalt/organic shingles.

Owens Corning: Roofing products are, like the two manufacturers above, just one element of a long line of residential building products, but in the case of Owens Corning, the market share is less dominant than its insulation products and some other lines. Still, Owens Corning offers a fairly wide range of products and a competitive set of builder/contractor support programs.

Tamko: Building Products Roofing division is more of a specialist in roofing materials other than asphalt but produces a line of asphalt shingles as well.