Roofing Terms Glossary
Navigating the world of roofing can be complex, with its own unique set of terminology and specialized concepts. Whether you’re a seasoned roofer, a roofing company owner, or someone looking to better understand roofing processes, this comprehensive glossary is designed to clarify the most common and essential terms in the industry. From foundational materials like asphalt and underlayment to specific techniques such as flashing and reroofing, our glossary provides clear, concise definitions to enhance your knowledge and streamline your projects. Use this resource to ensure effective communication, improve your craftsmanship, and stay informed about the latest standards and practices in roofing. Let’s build a stronger foundation together by mastering the language of roofing.
A
Algae Discoloration: Roof staining resulting from algae growth, often mistaken for other types of fungal contamination.
Algae Stain: A type of discoloration on roofs caused by algae, frequently confused with fungal growth.
ARMA (Asphalt Roofing Manufacturers Association): A North American trade group representing manufacturers of asphalt roofing products.
ASTM International: An organization dedicated to developing and publishing technical standards for a wide range of materials, including roofing.
Asphalt: A waterproofing material derived from bitumen, commonly used in the production of roofing products.
Asphalt Primer: A liquid bitumen applied to surfaces to improve the adhesion of self-adhering roofing membranes and to capture dust.
Asphalt Roof Cement: An adhesive based on asphalt used to bond roofing components; also known as flashing cement or mastic, and must meet ASTM D4586 standards for asbestos-free composition.
Architectural Shingles: Shingles with multiple layers, also called laminated or three-dimensional shingles, offering increased thickness and enhanced visual appeal.
B
Back Coating: Fine minerals applied to the underside of shingles to prevent them from sticking together.
Back Surfacing: Mineral matter applied to the back of shingles to avoid adhesion when bundled.
Battens: Thin strips of material (wood, plastic, or metal) used horizontally over joists to secure roofing materials like tiles or slates.
Base Flashing: The component of flashing installed directly on the roof deck to guide water onto the roofing material.
Base Ply Sheet: The foundational layer in a self-adhering roll roofing system, typically used in residential applications.
Base Sheet: The initial layer of material in a self-adhering roll roofing system, serving as the base for subsequent layers.
Base-ply Sheet: Another term for the base or middle layer in residential self-adhering roll roofing systems.
Blistering: The formation of bubbles on the surface of asphalt roofing materials following installation.
Blisters: Similar to blistering, these are bubbles that develop on asphalt roofing surfaces post-installation.
Bridging: A reroofing technique that utilizes shingles of metric dimensions.
Built-Up Roofing: A roofing system for flat or low-slope roofs composed of multiple layers of ply sheets embedded in hot asphalt.
Bundle: A packaged set of shingles, typically containing 3, 4, or 5 bundles to cover 100 square feet.
Butt Edge: The bottom edge of a shingle tab.
C
Cap Sheet: A top layer of rolled roofing material with a mineral surface, used alone or atop other layers in multi-layer systems.
Caulk: A sealing material, often mastic or asphalt cement, applied to joints to prevent water infiltration.
Cement: Commonly refers to asphalt roof cement, used as an adhesive in roofing applications.
Chalk Line: A straight line marked on the roof using chalk-dusted string or cord, assisting in alignment during installation.
Cladding: The arrangement of roofing materials overlapping each other to form a protective, waterproof exterior layer.
Class "A" Fire Rating: The highest fire resistance rating for roofing materials, indicating superior ability to withstand external fire sources according to ASTM E108 or UL790 standards.
Class "B" Fire Rating: A roofing fire resistance rating that denotes moderate protection against external fire sources.
Class "C" Fire Rating: A lower fire resistance rating for roofing materials, suitable for areas with minimal fire exposure.
Class 4 Impact Resistance: The top classification in UL 2218 impact testing, signifying maximum resistance to hail and other impacts.
Closed Cut Valley: A valley design where shingles from one side extend over the valley, while those from the opposite side are trimmed back, hiding the valley flashing.
Collar: A pre-shaped flange placed around vent pipes to seal the roof opening, also known as a vent sleeve.
Concealed Nail Method: A technique for applying roll roofing where nails are hidden beneath overlapping layers to protect them from weather exposure.
Condensation: The process where water vapor turns into liquid upon contacting a cooler surface, potentially leading to moisture issues in roofing systems.
Counter Flashing: Flashing installed on vertical surfaces to complement base flashing, preventing water from penetrating behind the primary flashing.
Course: A horizontal row of shingles or roll roofing laid across the roof.
Coverage: The number of roofing material layers applied over the deck, such as single or double coverage.
CRM (Customer Relationship Management): Software tools used by roofing companies to manage client interactions, job tracking, and sales processes.
Cricket: A peaked structure installed behind chimneys to divert snow and ice, preventing water accumulation and directing flow away.
Cutout: The open sections in a strip shingle between its tabs.
D
Deck: The structural surface installed over the framing, to which the roofing materials are attached. Typically made from plywood or OSB, with thickness requirements varying by local codes.
Decking: Similar to deck, referring to the installed surface supporting the roofing system.
Dormer: A protruding window unit that extends vertically through a roof, adding space and light to the attic or upper floors.
Double Coverage: Installing two layers of roofing material so that the overlapping section is at least 2 inches wider than the exposed part, providing enhanced protection.
Double Layer: Similar to double coverage, indicating the application of two roofing layers over the deck.
Downspout: A pipe that channels water from gutters down to the ground or drainage system, also known as a leader.
Drip Edge: A metal flashing installed along the roof's eaves and rakes to direct water away from the underlying structure.
E
Eave: The lower, horizontal edge of a sloped roof that extends beyond the building's exterior walls.
Eaves: Plural of eave; the collection of eaves around a building.
Eaves Flashing: Additional roofing material applied at the eaves to prevent water from backing up and causing damage.
Estimate: An approximate calculation of the total cost to complete a roofing project, including materials, labor, and profit margins.
Exposed Nail Method: A roofing technique where nails are driven through the roofing material and remain visible, exposed to the weather.
Exposure: The portion of roofing material that remains visible and uncovered after installation.
F
Fascia/Barge Board: Decorative and protective boards installed along the roof edges beneath the eaves, covering the ends of rafters or trusses.
Felt: An asphalt-saturated material used as an underlayment or sheathing paper to provide moisture protection.
Fiberglass Mat: The central component of asphalt shingles, made from glass fibers for added strength.
Flashing: Metal pieces installed around roof penetrations and joints to direct water away and prevent leaks.
Flashing Cement: Another term for asphalt roof cement, used to adhere and seal flashing materials.
Flat Roof: A roof with minimal slope, typically no greater than 15°, designed to sit nearly level atop a building. It consists of waterproofing, insulation, vapor barriers, substrates, joists, and plasterboard ceilings.
G
Gable: The triangular section of a wall between the edges of a dual-pitched roof.
Gable Roof: A roof with two sloping sides that come together at a ridge, forming a gable at each end.
Gambrel Roof: A roof with two different slopes on each side, the lower slope being steeper, commonly seen in barns.
Granules: Small, colored ceramic-coated particles embedded in shingles to provide UV protection and aesthetic appeal.
Gutter: A trough installed along the eaves to collect and channel rainwater to downspouts.
H
Head Lap: The shortest vertical distance from the bottom edge of an overlapping shingle to the top edge of the shingle below it, ensuring proper coverage.
Hexagonal Shingles: Shingles designed with a six-sided shape for a distinctive appearance once installed.
Hip: The external angle formed where two sloping roof planes meet, running from the ridge to the eaves.
Hip Roof: A roof type with sloping planes on all four sides, meeting at a ridge, and lacking gables.
Hip Shingles: Shingles specifically used to cover and protect the hip angles where roof planes intersect.
I
Ice Dam: A buildup of ice at the roof's edge, preventing proper drainage and causing water to back up under shingles, potentially leading to leaks.
Ice Dam Protection: Installation of additional underlayment layers at eaves to block water intrusion caused by ice dams, also known as eave flashing.
Ice & Water Shield: A specialized underlayment designed to protect vulnerable roof areas from ice dams and water infiltration, often made from polymer-modified bitumen.
Impact Resistant Shingles: Shingles engineered to withstand hail and other impacts, rated up to Class 4 under UL 2218 standards.
Insulation: Material used within the roofing system to provide thermal resistance, soundproofing, and fire protection.
J
Joists: Horizontal structural members that support the roof deck and transfer loads to the supporting walls or beams.
L
Layer: A single level or sheet of roofing material applied over the deck.
Laminated Shingles: Shingles with multiple layers, also known as three-dimensional or architectural shingles, offering greater durability and visual depth.
Lap: The overlapping of one shingle or roofing material over another to ensure waterproofing.
Lap Cement: Asphalt-based adhesive used to bond overlapping roofing layers, conforming to ASTM D3019 standards.
Low Slope Application: Installation method for roofing materials on roofs with gentle inclines, typically between 2 to less than 4 inches of rise per foot.
M
Mansard Roof: A roof with four sloping sides, each having two distinct pitches, where the lower pitch is steeper, often nearly vertical.
Mastic: A sticky, asphalt-based substance used as an adhesive in roofing, synonymous with asphalt roof cement.
Mid-ply Sheet: Another term for the base-ply sheet in roll roofing systems.
Mineral Stabilizers: Finely ground minerals added to asphalt shingles to improve durability and resistance to environmental factors.
Mineral-Surfaced Roofing: Roofing materials like shingles and roll roofing that are coated with granules for added protection and appearance.
N
Nesting: A reroofing technique where new shingles are installed directly over old ones, aligning the top edge of the new shingle with the bottom edge of the existing shingle tab.
No-Cutout Shingles: Shingles designed with solid tabs and without any cutouts for a uniform appearance.
Non-Veneer Panel: Wood-based panels without a laminated veneer, such as waferboard or oriented strand board, used in roofing structures.
O
Open Valley: A valley design where shingles are trimmed along chalk lines on both sides without extending over the valley, leaving the valley flashing exposed.
Organic Felt: A traditional roofing underlayment made from cellulose fibers, serving as a base layer for shingles.
Overhang: The portion of the roof that extends beyond the building's exterior walls, helping to direct water away from the structure.
Overlay: Installing new shingles over existing ones, aligning the new shingles' top edge with the existing shingles' bottom edge.
Overlap: The practice of covering one roofing material with another to create a layered, watertight surface.
Overlap Cement: Asphalt-based adhesive used to secure overlapping layers of roll roofing, meeting ASTM D3019 standards.
P
Pallets: Wooden platforms used to store and transport bundles of shingles and other roofing materials.
Plasterboard Ceiling: Part of flat roof construction, serving as the interior ceiling layer beneath the roof structure.
Ply: Individual layers of roofing material, such as one-ply or two-ply systems.
Ponding: Accumulation of water in low areas of a roof that remains stagnant while other sections dry.
Primer: An asphalt-based preparatory coating applied to surfaces to enhance the bonding of self-adhering roofing sheets.
Proposal (or Quote): A detailed offer from a roofing contractor outlining the scope, materials, costs, terms, and conditions for a roofing project.
Pitched Roof: A roof designed with a noticeable slope, typically exceeding 15 degrees, commonly featuring gable or hip configurations.
Pitched or Sloping Roofs: Roofs constructed with a significant incline, including types like gable and hip roofs.
Substrate: The base surface upon which roofing materials are installed, often timber decking such as plywood or OSB.
R
Racking: A method of applying shingles vertically up the roof to create a staggered appearance.
Rafter: Structural beams that extend from the ridge or hip of the roof down to the eaves, supporting the roof deck.
Rake: The sloped edge of a roof that extends beyond the wall, often finished with fascia and soffit.
Random-Tab Shingles: Shingles featuring varied tab sizes and exposures to create a more natural, staggered look.
Recovering: Adding an additional roofing layer over an existing one, typically limited to two layers by building codes.
Release Strip: A removable plastic layer on self-sealing shingles that prevents them from sticking together before installation.
Release Tape: Similar to release strips, this plastic tape keeps self-sealing shingles from adhering prematurely in bundles.
Reroofing: The process of removing existing roofing materials and installing a new roofing system in their place.
Ridge: The highest horizontal point where two sloping roof planes meet.
Ridge Shingles: Shingles specifically designed to cover and protect the ridge area of a roof.
Rise: The vertical measurement from the eaves to the roof ridge.
Roll Roofing: Asphalt-based roofing material supplied in continuous rolls, typically used for flat or low-slope roofs.
Roofing Tape: Asphalt-infused tape used alongside roof cements for sealing and repairing roofing components.
Roof Report: A comprehensive digital document detailing measurements, areas, pitches, and other specifications of a roof, often used for estimates.
Run: The horizontal distance from the eaves to a point directly below the ridge, equivalent to half the roof's span.
S
Saturated Felt: An underlayment material impregnated with asphalt, used between the deck and the roofing surface to provide moisture protection.
SBS (Styrene-Butadiene-Styrene): A synthetic polymer blended with asphalt to improve flexibility and performance of roofing materials.
Sealant: An asphalt-based product used to fill gaps and create waterproof seals in roofing installations.
Shading: Minor color variations in shingles resulting from the manufacturing process.
Sheathing: Also known as deck, it refers to the structural layer beneath the roofing materials, typically made of plywood or OSB.
Shed Roof: A single-sloped roof without hips, ridges, valleys, or gables.
Self-Adhering Shingle Underlayment: A peel-and-stick waterproof layer installed beneath shingles to guard against water infiltration from ice dams or heavy rain, compliant with ASTM D1970.
Self-Sealing Shingles: Shingles equipped with adhesive strips or spots that bond shingle courses when exposed to sunlight.
Self-Sealing Strip or Spot: Adhesive applied to shingles that activates with heat to secure them in place.
Selvage: The overlapping portion of roll roofing covered by the next course to ensure proper coverage.
Single Coverage: Installing one layer of roofing material over the deck.
Slope: The angle of roof incline, expressed as the ratio of vertical rise to horizontal run (e.g., a 4/12 slope means a 4-inch rise over a 12-inch run).
Smooth-Surfaced Roofing: Roll roofing finished with a smooth layer, often coated with talc or mica instead of granules.
Soffit: The underside area of the eaves, often ventilated to allow air circulation.
Soil Stack: A vertical vent pipe that passes through the roof, typically part of the plumbing system.
Span: The horizontal distance between two points of support, such as from eave to eave.
Square: A unit of measure in roofing equal to 100 square feet of coverage.
Square-Tab Shingles: Shingles with uniform tab sizes and consistent exposure for a regular appearance.
Standard Slope Application: Installation of asphalt shingles on roofs with slopes between 4 inches and 21 inches of rise per foot.
Starter Strip: The initial layer of shingles applied at the eaves to provide a secure base and enhance protection for the first course of shingles.
Staggering: A technique where shingle courses are offset vertically to avoid alignment and improve water shedding.
Steep Slope Application: Shingle installation on roofs with slopes exceeding 21 inches of rise per foot.
Step Flashing: Metal flashing installed in a series of overlapping steps where a vertical wall meets a sloping roof to prevent water intrusion.
Strip Shingles: Single-layer asphalt shingles, typically three times longer than they are wide.
Synthetic Underlayment: A modern alternative to felt underlayment, made from materials like polypropylene for enhanced durability and water resistance.
Tab: The visible portion of a shingle, defined by its cutouts.
Talc: A mineral used in back surfacing to prevent shingles from sticking together.
Tear Off: The complete removal of existing roofing materials down to the structural deck before installing a new roof.
Telegraphing: Visible imperfections in shingles caused by installing new roofing over an uneven underlying surface.
Three-Dimensional Shingles: Shingles with a layered structure that provides a textured, elevated appearance, also known as laminated or architectural shingles.
Top Lap: The portion of a shingle layer that is covered by the succeeding course after installation.
U
Underlay: A thin layer of waterproof and insulating material placed beneath roofing tiles or shingles.
Underlayment: Protective material installed beneath the main roofing surface, such as asphalt-saturated felt or synthetic alternatives, to provide additional moisture protection.
UL (Underwriters Laboratories, LLC): An independent organization that tests and certifies products for safety and performance standards.
UL Label: Certification marks on roofing products indicating their compliance with UL standards for fire and wind resistance.
V
Valley: The internal angle formed where two roof planes intersect, directing water flow down the roof.
Valley Gutter: A gutter installed within the valley to collect and channel water where two roof slopes meet.
Vapor Retarder: Material used in roofing systems to impede the passage of water vapor, preventing moisture buildup.
Vent: An opening in the roof that allows air circulation within the attic or roof structure, including pipes and ventilating devices.
Vent Sleeve: Also known as a collar, it is a flange placed around vent pipes to seal the roof opening.
W
Wall Flashing: Metal flashing installed where the roof meets a vertical wall, preventing water from seeping behind the wall and causing leaks.
Woven Valley: A valley construction method where shingles from both roof planes extend into the valley and interweave with alternating courses, concealing the valley flashing.