The Allowable Overhang for a Tin Roof

Overhangs

• An overhang is a piece of roof that's extended past the top of the house. Another term for an overhang is an eave. The amount of permissible overhang for a roof is dependent on many factors, including the pitch and sheeting distribution of the roof, and tin roofs are no exception.

Allowable Length

• Without the use of outriggers, a tin roof should not have an overhang that exceeds 11 inches, or 300 millimeters. Any greater length will put too much strain on the roof and can cause warping.

Ideal Overhang Angles

• An overhang should be set up to provide rain protection as well as to shade any windows below. As a general rule, the overhang should have a 40-degree angle from the home’s wall and an 80-degree angle from the ground.

Use of Outriggers

• When outriggers are used to support the tin roof’s overhang, the overhang can be expanded to as much as 2 meters (about 6 feet). Outriggers are posts that are secured to the ground and are meant to provide greater stability. Outriggers are especially common for porch overhangs.