Common Roofing Terms Explained

Roof slope describes how steep a roof is. Contractors often use “pitch” to mean the same thing and express it as a ratio, such as 6:12. A 6:12 slope rises 6 inches for every 12 inches of horizontal distance. Slope affects material selection, drainage, and installation requirements.

The ridge is the highest horizontal line where two sloping roof sections meet. On many homes, it runs along the peak of the roof.

A hip is the outward-facing line where two sloping roof sections meet. Hip roofs have slopes on all sides, rather than vertical gable ends.

A valley is the inward-facing intersection between two roof slopes. Valleys collect water from adjoining roof sections and direct it toward the eaves, making proper installation especially important.

The eave is the lower edge of a roof, usually extending beyond the exterior wall. Gutters are commonly installed along the eaves.

The rake is the sloped edge of a roof at a gable end. Unlike the eave, it runs upward toward the ridge.

A gable is the triangular portion of an exterior wall between two sloping roof edges. A typical gable roof has two main slopes that meet at a ridge.

A roof plane is one flat, sloped section of a roof. A simple roof may have only a few planes, while a more complex roof may have many.

A dormer is a structure that projects from a sloped roof, often containing a window. Dormers create additional corners and roof-to-wall connections that require careful flashing.

A low-slope roof has a shallow incline. These roofs require materials and installation methods suited to slower water drainage. A roof that appears flat typically still has some slope to move water toward drains or edges.

Roof decking is the surface attached to the roof framing that supports the roofing system. It is commonly made from plywood or oriented strand board, although some homes have board decking. Damaged decking may need replacement before new roofing is installed.

OSB stands for oriented strand board. It is an engineered wood panel commonly used for roof decking.

Rafters are sloped structural members that support the roof deck. They transfer roof loads to the supporting walls and other framing.

Trusses are engineered framing assemblies that support the roof. They typically use connected members arranged in triangular patterns.

Fascia is the trim board along the roof edge, commonly located behind the gutters. Deteriorated fascia can affect gutter attachment and may indicate an underlying moisture problem.

The soffit is the underside of a roof overhang. Some soffits contain vents that allow outdoor air to enter the attic as part of its ventilation system.

Asphalt shingles are a common residential roofing material. They typically contain a reinforcing mat, asphalt, and a surface layer of protective mineral granules.

Architectural shingles, also called dimensional or laminated shingles, have multiple layers that create a thicker, textured appearance. Product designs, performance ratings, and warranty terms vary.

Three-tab shingles have a flatter appearance with regularly spaced cutouts. They are commonly found on older roofs and generally have a more uniform pattern than architectural shingles.

Starter shingles form the beginning course along designated roof edges. They help protect shingle joints at the edge and provide the sealant placement needed for the roofing system.

Ridge cap shingles cover the roof’s ridges and hips. They are shaped or manufactured for these locations and help protect the intersections between roof planes.

Underlayment is a protective layer installed between the roof decking and the primary roofing material. It provides a secondary layer of protection against water that gets beneath the roof covering.

Synthetic underlayment is made from engineered materials rather than traditional asphalt-saturated felt. Its properties vary by product, including tear resistance, traction, and allowable exposure time.

Roofing felt is a traditional underlayment made with an asphalt-saturated base material. It is sometimes referred to as felt paper or tar paper.

Often called ice and water shield, this membrane adheres to the roof deck and provides additional water protection in selected areas. Depending on the roofing system, it may be used in valleys, around penetrations, or along roof edges.

Metal roofing uses metal panels or shingles as the primary roof covering. Different systems have different fastening methods, slope requirements, finishes, and maintenance needs.

Standing seam is a type of metal roofing with raised seams connecting adjacent panels. Many standing seam systems conceal the fasteners beneath the panels or seams.

An exposed-fastener system uses fasteners that pass through the face of the metal panels. Fasteners and sealing washers remain exposed to weather and need periodic inspection.

Flashing is material installed at roof joints, transitions, and openings to direct water away from vulnerable areas. Common locations include chimneys, walls, valleys, and vent pipes.

Step flashing consists of individual pieces installed where a sloped shingle roof meets a vertical wall. The pieces overlap with the shingle courses to direct water down the roof.

Counterflashing covers and protects the upper edge of another flashing component. It is commonly used at masonry chimneys and walls to help keep water from getting behind the base flashing.

Drip edge is metal flashing installed along roof edges. It helps direct water away from vulnerable roof-edge components and supports proper drainage at the perimeter.

Valley flashing protects the channel where two roof slopes meet. Some systems have visible metal valleys, while others use shingles and underlying protective materials.

A pipe boot is a flashing assembly that seals around a pipe passing through the roof. A cracked or deteriorated boot can allow water to enter around the pipe.

A penetration is an opening through the roof for a pipe, vent, skylight, or other component. Each penetration needs an appropriate flashing or sealing detail.

A cricket is a small roof structure that redirects water around the uphill side of a chimney or another obstruction. It helps prevent water and debris from collecting behind the obstruction.

Kickout flashing directs water away from the bottom of a roof-to-wall intersection and toward the gutter. It helps protect siding and wall components from concentrated runoff.

Sealant is a material used to close certain joints or gaps. It has specific applications within a roofing system, but it does not replace properly designed flashing.

Intake vents allow outdoor air to enter the attic, usually near the lower roof edge. Soffit vents are a common example.

Exhaust vents allow attic air to leave, usually near the upper portion of the roof. They work with intake vents to support airflow through the attic.

A ridge vent is installed along the roof peak to provide attic exhaust ventilation. It is typically covered with compatible ridge cap shingles.

A soffit vent is an opening in the underside of the roof overhang that provides attic intake ventilation. Insulation and other obstructions should not block its intended airflow path.

A baffle helps maintain an open air passage between the soffit area and attic. It can prevent insulation from blocking airflow near the eaves.

Balanced ventilation refers to an appropriately sized and distributed combination of intake and exhaust. The correct arrangement depends on the roof, attic, and ventilation system.

A roofing square equals 100 square feet of roof area. For example, 2,000 square feet of roof surface equals 20 squares before accounting for waste.

A bundle is a package of shingles. The number of bundles needed to cover one roofing square varies by product.

Roof area is the actual surface area of the roof. It differs from the home’s interior square footage because it accounts for slopes, overhangs, and roof geometry.

A waste factor is an allowance for material used in cuts, fitting, and layout. Roofs with more valleys, hips, and other complex details generally require more cutting.

A tear-off is the removal of existing roofing materials before a new roof is installed. It allows the underlying decking to be inspected and necessary repairs to be made.

An overlay installs a new roof covering over an existing layer. Whether it is appropriate or permitted depends on the existing roof, applicable requirements, and the selected materials.

A decking allowance identifies a quantity or budget included for replacing damaged roof decking. Estimates should explain how additional decking replacement will be priced if more damage is uncovered.

The scope of work describes what a contractor’s proposal includes. It should identify the materials, removal work, installation details, cleanup, and other agreed services.

A roof leak occurs when water enters through the roofing system. The entry point may be some distance from the stain or dripping visible inside the home.

Wind damage can include lifted, creased, loosened, or missing roofing materials. Determining the extent of damage requires inspecting the affected roof components.

Hail damage is physical damage caused by hail impacts. Its effects depend on factors such as the roofing material, its condition, and the characteristics of the storm.

Granule loss occurs when the protective surface particles come off asphalt shingles. Some loose granules are normal, particularly on a new roof, while concentrated or excessive loss may warrant inspection.

Curling describes shingle edges or tabs turning upward or changing shape. It can be associated with aging, material condition, or other roofing issues.

Buckling describes raised or distorted areas in the roof covering. Possible causes include movement or irregularities in the materials beneath the shingles.

A nail pop occurs when a nail backs out or pushes upward, sometimes lifting the shingle above it. It may create a vulnerable area that needs repair.

An exposed fastener has a head visible to the weather. Some roofing systems are designed with exposed fasteners; in other locations, an exposed fastener may indicate an installation or maintenance issue.

Ponding is water that remains collected on a roof instead of draining as intended. It is primarily a concern on low-slope roofing systems and should be evaluated in the context of that system.

A roof repair addresses a specific issue or damaged area. The appropriate repair depends on the cause, the surrounding material condition, and the roof’s overall condition.

A roof replacement installs a new roofing system after the required removal and preparation work. The proposal should explain which components will be replaced and how any concealed damage will be handled.

A manufacturer’s warranty provides coverage subject to the terms of the roofing product or system warranty. Coverage, exclusions, and installation requirements vary.

A workmanship warranty addresses covered installation-related issues under the contractor’s stated terms. It is separate from the manufacturer’s product warranty.

Prorated coverage changes over time according to the warranty’s terms. As a roof ages, the amount covered for an eligible claim may decrease.