Ibc Min Roof Slope

The minimum roof slope for metal roof panels depend on 3 different scenarios.

Ibc min roof slope. Minimum slope for asphalt shingles the requirements for an asphalt shingles roof are contained in the international building code. So typically we follow 2 slope is that meeting the code even if the slope is slight shy of 1 4 per foot. Ibc callouts for min 2 or 1 4 per foot. For roof slopes from two units vertical in 12 units horizontal 17 percent slope up to four units vertical in 12 units horizontal 33 percent slope double underlayment application is required in accordance with section 1507 2 8.

The code may still have a provision for hot mopped asphalt but i cannot see this being used in the middle east. Asphalt shingles shall only be used on roof slopes of two units vertical in 12 units horizontal 17 percent slope or greater. Lap sealants shall be applied in accordance with the approved manufacturer s installation instructions. When required for steep slope roofs section 1507 in the ibc and section r905 1 2 of the irc specify the use of an ice barrier that consists of either two layers of underlayment cemented together or a self adhering polymer modified bitumen sheet at eaves and valleys.

According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. The ibc minimum required roof slope is 1 4 in 12 which is about 1 2 degrees for a membrane roof. This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof systems in new construction. Lapped nonsoldered seam metal roofs without applied lap sealant must have a minimum roof slope of 3 12 25 slope.

The minimum slope for lapped nonsoldered seam metal roof panels without applied lap sealant shall be three units vertical in 12 units horizontal 25 percent slope. 2 exactly does not translate to 1 4 per foot. If you are using a metal panel roof then you may need to go steeper. Built up roofs shall have a design slope of a minimum of one fourth unit vertical in 12 units horizontal 2 percent slope for drainage except for coal tar built up roofs that shall have a design slope of a minimum.

For metal panel roof systems with nonsoldered seams with applied lap sealant ibc 2018 prescribes a 1 2 12 minimum roof slope. I understand this is more of rounding off to get to a nice number. For standing seam metal roof panel systems a 1 4 12 minimum roof slope is prescribed. I am looking at the ibc minimum roof slope requirement for standing seam metal roof.

This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units.