Flat Roof Slope Requirements

This means that the rise of the slope goes up or down 8 inches for every 12 inches.

Flat roof slope requirements.

Express the slope of a metal roof by a ratio which indicates the pitch of the roof. Cold roofs have the waterproof layer placed directly onto the roof deck and the insulation inside the roof just above the ceiling. Asphalt shingles continue to be the most widely installed roof covering option in north america. Proper roof slope can be an important consideration when designing high performance roof systems.

An example for a steep sloped roof is 8 12. 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. Minimum slope for roofing materials. Roof pitch multiplier table.

The profile is the shape taken by the sheets when you bend them to form panels. 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. Degrees to pitch rise in run table. To put it in perspective the angle of this slope would be around 30 degrees.

The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. All of these codes are produced by the international code council icc. Roof slope equivalents as rise. You need to consider the slope requirements of each panel to determine this minimum slope.

However you can only use this pitch with built up roofing or specialized synthetic roofing. The minimum slope of a roof depends on the roof s profile. Roof pitch or roof slope. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches. Following is a review of code requirements and nrca s roof slope guidelines as well as some additional factors designers should consider. Quick roofing guide to the international building code. There are two types of flat roof.

First off lets get some terminology out of the way. Cold roofs and warm roofs. 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. Minimum and maximum roof slope limits vary based on specific roof system and project types.

Run in degrees and as percentage the minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. In general the minimum slope for a flat roof is 1 0 but as stated earlier this is only possible in theory.