Roofing Terms & Definitions

Asphalt Shingles are a common roofing material composed of a fibreglass or organic mat coated with asphalt and granules. Asphalt shingles are popular due to their affordability and aesthetic appeal.

Roof blisters are bubbles that may form on the surface of an asphalt roof after installation. These blisters are typically caused by the accumulation of moisture or gas within the layers of the roofing material.

A buckle in a roofing system is a displacement of a roof membrane that has continued to occur over insulation or deck joints. A roof buckling may be a result of the roof deck shifting or the underlayment wrinkled.

A cap sheet is a top layer or membrane in a multi-ply roofing system that serves as the weatherproofing layer that protects the underlying roofing materials from UV radiation, moisture, and other environmental elements.

The amount of weather protection provided by the specific roofing material. This depends on the number of layers of material used between the exposed surface and the roofing deck resulting in single coverage, double coverage, etc.

Also known as a downpipe or rainwater pipe, downspouts are vertical pipes connected to your roof’s gutters that direct rainfall from the gutters to the ground. Its primary purpose is to divert water from a building’s foundation to prevent water damage and erosion.

A drip edge is a plastic or metal flashing located on the edges of a roof, designed to keep water away from the fascia & other roof components.

Are the underside of your roof that overhangs and helps to protect your home’s siding and foundation. There are 3 common types of eaves:

1. Closed eaves

   Overhang that is closed with a soffit

2. Open eaves

   Overhang that is not equipped with a soffit, i.e. you can directly see the rafters

3. Boxed eaves

   Overhang that is enclosed by soffits and molding and conceals the rafters

Boards found on a roof’s overhang that help hold up your gutters and support your shingles.

A layer of waterproof material on your roof that prevents water leaks by directing the flow down the roof and into your gutter system. There are several different types of flashing, including:

• Counter flashing
• Base flashing
• Step flashing
• Continuous flashing

A gable roof is a roof with two sloping sides that meet at a central ridge, forming a triangular gable at each end.

A trough that’s placed on the perimeter of a roof and works to collect and discharge rainwater from your roof to the ground.

Gutter guards are gutter coverings that are designed to catch debris on your roof.

A roof design with all sides sloping down to meet at a central ridge or peak. These types of roofs are often found on houses with four sloping sides.

A ridge of ice typically found on the edge of your roof that occurs when snow keeps thawing and refreezing, preventing melting snow from properly draining off the roof. Can lead to damaged gutters, walls, insulation, etc.

A style of roof with steep slopes on all sides, creating extra living space within the attic or upper level of a building.

A metal roof is primarily made of steel or aluminum and is designed to provide long-lasting protection for buildings.

Rafters are long wood boards used to frame a roof. They are sloping beams that provide the main framework and support for the roof deck and roof materials.

The outer part of a gable roof and covers a roof’s top edge, it refers to the sloped sides at the end of a gable.

Also called roof sheathing, roof decking are the wooden boards that make up the foundation of your roofing system. It is what all roofing components are secured to.

Roofing nails are specialized nails used for securing roofing materials to the roof deck. They are designed to withstand exposure to weather as well as resist corrosion.

A roof pitch is a calculation that determines the steepness of a roof. It describes the angle or incline of the roof surface, indicating how much the roof rises vertically for every horizontal foot or meter it extends. It can be expressed in ratios, degrees, or percentages.

The surface a roofing system is applied on is called a roof substrate. It can include the roof deck, insulation system, or a pre-existing roof system. The type of substrate used for a roofing system depends on the type of construction and unique needs of the building.

A roof truss is a prefabricated structural framework made of wood or metal that supports the roof’s weight and shape. Trusses are designed to evenly distribute the load to the walls and provide structural integrity.

Is installed directly on your roof deck and acts as a barrier to protect your roof from the elements. There are three main types: felt, self-adhered, and synthetic.

A skylight is a window or transparent panel installed in a roof to allow natural light to enter a building, often with a frame designed to be water-resistant.

Soffits are the exposed siding beneath a roof’s overhang (eaves) that help with your home’s ventilation between the roof and the attic.

A sun tunnel is a tubular skylight that can be used in areas where a traditional skylight cannot be installed. Commonly used in bathrooms, hallways, closets, and other spaces.

A valley refers to the v-shaped area where two roof slopes intersect, often requiring special flashing to prevent water from accumulating and leaking into the building.

Any device used to allow air to escape from the underside of the roof deck. A vent usually protrudes through the roof deck like a pipe or stack.