Flat Roof Slope Requirements

An example for a steep sloped roof is 8 12.

Flat roof slope requirements.

Minimum and maximum roof slope limits vary based on specific roof system and project types. Quick roofing guide to the international building code. Since they vary in quality as well as method of installation the choice preferred for a flat roof will ultimately have an effect on the final slope of the flat roof. First off lets get some terminology out of the way.

The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches. Roof pitch or roof slope. Minimum slope for roofing materials. Iecc is of particular importance to low slope roof design due to its r value requirements which affect the amount of insulation that has to be included in roof assemblies.

Proper roof slope can be an important consideration when designing high performance roof systems. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. The profile is the shape taken by the sheets when you bend them to form panels. Complete list of roofing types.

Cold roofs have the waterproof layer placed directly onto the roof deck and the insulation inside the roof just above the ceiling. Roof slope equivalents as rise. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. Degrees to pitch rise in run table.

Asphalt shingles continue to be the most widely installed roof covering option in north america. Cold roofs and warm roofs. Following is a review of code requirements and nrca s roof slope guidelines as well as some additional factors designers should consider. All of these codes are produced by the international code council icc.

The steeper the roof slope the less potential for water to backup however the roofing materials established in chapter 9 must meet to minimum slope requirements. There are two types of flat roof. Express the slope of a metal roof by a ratio which indicates the pitch of the roof. The minimum slope of a roof depends on the roof s profile.

In general the minimum slope for a flat roof is 1 0 but as stated earlier this is only possible in theory. Roof pitch multiplier table. This means that the rise of the slope goes up or down 8 inches for every 12 inches. However you can only use this pitch with built up roofing or specialized synthetic roofing.

You need to consider the slope requirements of each panel to determine this minimum slope. To put it in perspective the angle of this slope would be around 30 degrees.