Minimum Slope For Roof Drainage

For standing seam metal roof panel systems a 1 4 12 minimum roof slope is prescribed.

Minimum slope for roof drainage.

These considerations include the length of the roof the roofing material the size of the roof as well as the. Minimum roof pitch the minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. 1 see sentence 9 26 3 1 2. 2 see sentence 9 26 3 1 3.

This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. Asphalt shingles minimum roof slope roof pitch r905 2 2. 2 asphalt and gravel or coal tar and gravel roofs may be constructed with lower slopes than required in sentence 1 when effective drainage is provided by roof drains located at the lowest points on the roofs. To put it in perspective the angle of this slope would be around 30 degrees.

The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. Asphalt shingles continue to be the most widely installed roof covering option in north america. This means that the rise of the slope goes up or down 8 inches for every 12 inches. Toilet waste lines are often 3 or 4.

They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. An example for a steep sloped roof is 8 12. 3 profiled metal roof cladding systems specifically designed for low slope applications are. Asphalt shingles can only be installed on roof slopes of 2 12 or greater.

How to use the calculator. It can be argued that the minimum roof slope for drainage is 1 0 since this is sufficient to allow water to flow but there are other design considerations that must be taken into account when determining the final minimum slope. Drain pipe slope calculator. The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.

For metal panel roof systems with nonsoldered seams with applied lap sealant ibc 2018 prescribes a 1 2 12 minimum roof slope. First figure out the diameter of the pipe you are working with. Notes to table 9 26 3 1. Roof replacement or roof recover of existing low slope roof coverings shall not be required to meet the minimum design slope requirement of one quarter unit vertical in 12 units horizontal 2 percent slope in section 1507 for roofs that provide positive roof drainage.

For household sinks the drain pipe diameter is often either 1 5 or 2.