Is the Pitch of a Roof Considered With Steel Roofs?

Steel on Low Pitch Roofs

• Corrugated or standing seam steel roofs work well at a low pitch, because their surfaces are slick and shed water and snow better than rough textures like asphalt shingles. Basic corrugations are 2 1/2 by 1/2; the tops of the corrugated peaks are 2 1/2 inches apart, the valleys between are 1/2 inch deep. Standing seams will vary -- these have wide flat areas with vertical seams for strength and to interlock panels.

Pitches Vary

• Recommended pitches for steel roofs vary. Some suppliers use a 6/12, 6-inch rise per foot, as the upper limit, but metal roofs in very snowy areas (like mountain regions) might have steeper slopes. Some installers suggest 3/12 as the minimum pitch for a metal roof, but others go as low as 1/12, which is basically flat. The weight, or thickness, of the metal and the amount of roof to be covered will affect what the pitch needs to be.

Low Pitch Is Cheaper

• Low-pitch steel roofs use less material and are usually cheaper. However, low-pitch roofs are more subject to heavy loads, such as the weight of snow, and might require thicker steel, which is more expensive. Higher pitch roofs more effectively shed rain and snow.

Find the Pitch

• You can easily determine the pitch of an existing steel roof. Set a level on top edge of the roof, and get the bubble in the level centered. Measure 12 inches along the level, then measure the distance between the bottom of the level and the roof surface. That is the pitch.