Ibc Min Roof Slope

This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof systems in new construction.

Ibc min roof slope.

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. 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. 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.

According to this code the minimum slope for asphalt shingles is 17 degrees or two vertical units to twelve units in the horizontal. This means for every 12 horizontal units the roof must rise a minimum of 3 vertical units. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures. Lap sealants shall be applied in accordance with the approved manufacturer s installation instructions.

The ibc minimum required roof slope is 1 4 in 12 which is about 1 2 degrees for a membrane roof. 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. If you are using a metal panel roof then you may need to go steeper. Ibc callouts for min 2 or 1 4 per foot.

The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. 2 exactly does not translate to 1 4 per foot. Asphalt shingles shall only be used on roof slopes of two units vertical in 12 units horizontal 17 percent slope or greater. Lapped nonsoldered seam metal roofs without applied lap sealant must have a minimum roof slope of 3 12 25 slope.

So typically we follow 2 slope is that meeting the code even if the slope is slight shy of 1 4 per foot. The minimum slope for lapped nonsoldered seam metal roof panels with applied lap sealant shall be one half unit vertical in 12 units horizontal 4 percent slope. The code may still have a provision for hot mopped asphalt but i cannot see this being used in the middle east. For metal panel roof systems with nonsoldered seams with applied lap sealant ibc 2018 prescribes a 1 2 12 minimum roof slope.

Minimum slope for asphalt shingles the requirements for an asphalt shingles roof are contained in the international building code.