Roofing Key Terms

In roofing there are various terms and concepts that are essential for understanding the components, materials, and techniques used in the construction and maintenance of roofs.

Commonly used roofing terms

Pitch

Pitch refers to the slope or angle of a roof, typically measured in inches of vertical rise per foot of horizontal run. It determines how water drains off the roof and is often expressed as a ratio (e.g., 4:12 pitch).

Decking

Roof decking, also known as sheathing, is the structural foundation of the roof. It is typically made of plywood or oriented strand board (OSB) and provides a flat surface for attaching roofing materials.

Underlayment

Underlayment is a water-resistant or waterproof membrane installed directly onto the roof decking before the roofing material is applied. It provides an additional layer of protection against water infiltration and helps to prevent leaks.

Flashing

Flashing is a thin metal or waterproof material used to direct water away from critical areas of the roof, such as valleys, chimneys, skylights, vents, and junctions between different roof planes. It helps to prevent water penetration and leaks at vulnerable points.

Shingles

Shingles are individual overlapping roofing units made of various materials, including asphalt, wood, metal, and slate. They are the most common roofing material used for residential roofs and come in different styles, shapes, and colours.

Ridge

The ridge is the highest point of a roof where two roof planes meet. Ridge vents or ridge caps are installed along the ridge to allow for proper ventilation and to protect against water infiltration.

Eaves

Eaves are the horizontal edges of a roof that overhang the walls of the building. They provide protection from the elements and help to direct water away from the exterior walls and foundation.

Fascia

Fascia is a vertical finishing edge located along the eaves of the roof. It covers the ends of the roof rafters and provides a smooth, finished appearance to the roofline.

Soffit

Soffit is the underside of the eaves that extends from the fascia to the exterior wall of the building. It may contain ventilation openings to allow for air circulation in the attic space and prevent moisture buildup.

Valley

A valley is the intersection of two sloping roof planes, forming a V-shaped trough where water flows towards the gutters or downpipes. Valley flashing is installed in these areas to prevent water infiltration and leaks.

Gutters

Gutters are channels attached to the eaves of the roof that collect and redirect rainwater away from the building's foundation. They help to prevent water damage to the roof, walls, and landscaping.

Drip Edge

Drip edge is a metal flashing installed along the edges of the roof to direct water away from the fascia and into the gutters. It helps to prevent water damage and rot at the roof edges.