Glossary
Browse common terms used in commercial and residential roofing. Select a term below or use the search to find specific definitions.
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- Balanced Attic VentilationBuilding Science - Balanced attic ventilation describes an attic that has an adequate amount of air coming in at the bottom and air exiting at the top to continuously release... More
- Ballasted RoofPerformance – Ballasted roofs use the weight of ballast to hold a roof membrane in place rather than adhesives or fasteners. More
- Box GuttersComponent - A box gutter is a rectangular gutter that is built into the roof edge or wall structure and directs water to discharge points like downspouts, typically used on... More
- Bridging (Roofing)Roof Problems - Bridging (delamination) occurs when a low-slope roof membrane spans over a transition instead of lying taut against the surface below. More
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- Change OrderCompliance - A change order is a written agreement that updates a construction contract when the work’s scope needs to change. More
- Cold WeldRoof Problems - A cold weld is an area in a heat-welded seam that failed to fuse completely during installation. More
- Coping CapComponent - A coping cap is a covering installed on top of a wall at the roof edge that covers and protects where the roof covering ends. More
- Core SampleInspection - A core sample (core cut) is a small, cylindrical section of a roof system that is cut and removed to evaluate the roof’s construction, materials, thickness, and condition... More
- Cricket (Roofing)Component – A roof cricket (saddle) is a sloped structure that diverts water to either side of a vertical structure like a chimney or wall. More
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- Date of LossCompliance - The date of loss is the date a specific storm or weather event caused damage cited in an insurance claim. More
- DegranulationRoof Problems - Degranulation (granule loss) is the loss of protective granules from the surface of asphalt roof materials such as shingles and modified bitumen. More
- Drip EdgeComponent - Drip edge is a metal flashing piece installed at the edge of the roof that directs water away from the roof deck, fascia and wall below. More
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- EaveArchitectural Features - An eave is the lower roof edge that extends past the exterior wall, usually where water leaves the roof and enters a gutter. More
- Exposed FastenerRoof Problems -An exposed fastener is a nail or screw head that is visible on the roof surface and not protected by overlapping roofing material or sealant. More
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- Heat-Welded Seam (Roofing)Installation - A heat-welded seam is the connection between two membrane sheets that have been fused together with hot air and pressure to create one, continuous waterproof surface. More
- Hydraulic Lift TrailerEquipment - A hydraulic lift trailer is a drivable trailer that raises to the roofline to collect debris and lift materials during roofing projects. More
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- Ice and Water ShieldComponent - Ice and water shield is a waterproof layer installed beneath shingles or other roof coverings in leak-prone areas of a roof. More
- Internal DrainComponent - An internal drain is a roof drain installed in the roof surface that collects water and directs it into piping inside the building. More
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- LayoverInstallation – A layover (recover or overlay) is a method of installing a new roof membrane over an existing roof system without removing the existing roof. More
- Low-Slope RoofsRoof Types - Low-slope roofs (flat roofs) are a type of roof system with less than a 3:12 pitch, most commonly found on commercial and industrial buildings. More
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- Parapet WallsComponent - A parapet wall is the portion of an exterior wall that extends above the roofline at the perimeter of some buildings. More
- Passive Attic VentilationBuilding Science - Passive attic ventilation is attic airflow that moves through vents without a fan, motor or other powered equipment. More
- PenetrationComponent - A roof penetration is an opening where something passes through the roof surface, such as a plumbing pipe or an HVAC unit curb. More
- Polyiso InsulationComponent - Polyiso (polyisocyanurate) is an insulation board installed beneath many low-slope roof membranes to improve a roof system’s energy efficiency. More
- PondingRoof Problems - Ponding water is accumulated water that remains on a roof surface for more than 48 hours after rainfall. More
- Pull TestCompliance - A pull test measures how strongly a roofing fastener grips the roof deck by determining the force required to pull it out. More
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- R-Value (Roofing)Building Science - In roofing, R-value is a measure of thermal resistance, or how well a roofing material slows down heat from moving through it. More
- Roof CoatingPrimary Roof Covering - A roof coating is a protective layer applied over an existing roof intended to extend its service life. More
- Roof CurbComponent – A curb is a raised frame for a rooftop penetration that supports equipment and elevates it above the roof surface. More
- Roof DeckComponents - A roof deck is the structural surface connected to a building’s framing that supports the roof system installed above it. More
- Roof HatchComponent - A roof hatch is a framed opening onto the roof for recurring access from the interior of a building. More
- Roof SystemRoof Types - A roof system (roof assembly) is the entire series of roofing layers and components above the roof deck that work together to weatherproof the building. More
- Roof Walkways (Walkway Pads)Component - Roof Walkways (Walkway Pads) are protective surfaces that can be installed on roof surfaces to create durable walking paths around access and service points. More
- RUSS StripComponent - RUSS (Reinforced Universal Securement Strip) is used in single-ply roofing systems to secure the membrane at transitions like walls and corners while reducing stress on the membrane. More
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- Single-Ply MembranePrimary Roof Covering - A single-ply membrane is a roof covering that uses one continuous layer of material to waterproof low-slope roofs. More
- SoffitArchitectural Features - A soffit is the underside of a roof overhang, covering the area where the roof edge and attic space meet the outside air. More
- Split BootComponent – A split boot is a type of flashing with a built-in seam that allows it to wrap around a penetration when a standard one-piece boot cannot be installed... More
- Structural SlopePerformance - Structural slope is the intentional pitch built into a roof’s framing or deck to direct water toward drains or roof edges. More
- Synthetic RoofingPrimary Roof Covering - Synthetic Roofing (synthetic covering) is manufactured with polymer or plastic designed to resemble natural roof coverings such as wood shake, slate or clay tile. More
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- Tapered InsulationComponent - Tapered insulation is insulation manufactured with varying thicknesses to create slope and direct water across a low-slope roof. More
- TelehandlerEquipment - A telehandler is a lift machine with an extendable boom that roofing crews use to load materials and manage debris around steep and hard-to-reach roofs. More
- Termination BarComponent - A termination bar (T-bar) is a metal strip used to secure and seal the edge of a roof membrane where it ends against a vertical surface. More
- Thermal Bridging (Roofing)Building Science - Thermal bridging occurs in roofing when a conductive material, like a metal fastener, creates a path for heat to move through the insulation around it. More
- Thermal MovementBuilding Science - Thermal expansion is the movement of roofing materials as they expand when heated and contract when cooled. More
- TPOPrimary Roof Covering - TPO (thermoplastic polyolefin) is a white roof covering used on flat (low slope) roofs, commonly installed on commercial buildings to create a continuous waterproof surface. More
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