When you are deciding on a roofing project, its important to make sure you have all the information so you can make an informed decision.

However, roofers often use some terminology that can be difficult to understand if you are unfamiliar with it. It may be a good idea to learn a few terms before you contact a roofing contractor.

Below is a list of some of the most common roofing terms you are likely to hear when dealing with a roofing contractor.

Ballast: A material such as aggregate which employs its mass and the force of gravity to hold singly-ply roof membranes in place.

Counter Flashing: Metal or elastomeric sheeting secured on or into a wall curb, pipe, rooftop unit, or other surface to protect the upper edge of the base flashing.

Cricket: A small, elevated area used to divert water from a horizontal intersection of the roof with a chimney, wall, expansion joint or other projection.

Curb: A raised component used to support and raise equipment and penetrations on the roof. Things such as HVAC units, skylights, hatches and anything else above the level of the roof surface.

Deck: The structural base of the roof that everything else goes on top of. Typically made of wood, concrete or steel as they need to be able to support the weight of the rest of the roof system.

Drip Edge: A metal flashing or other overhanging component intended to control the direction of dripping water.

EPDM: Ethylene Propylene Diene Monomer is an extremely durable rubber roofing membrane and is one of the most common on flat roofs.

Flashing: Weatherproofing components used to seal roof system edges at perimeters, walls, expansion joints, valleys, drains and other places

Mechanically Fastened Membrane: Membranes that have been attached at defined intervals to substrate using fasteners or other mechanical devices.

Modified Bitumen: This is a roofing system composed of asphalt or tar. Layers of fiberglass or polyester are added to the asphalt or tar.

Parapet Wall: Perimeter wall that extends above the roof surface, ranging in height.

Penetrations: Any element that passes through the roof, such as, pipes, conduits, and HVAC supports.


When you are speaking with a contractor and are still having trouble understanding some of the terminology, don’t hesitate to ask for more clarification.