Minimum Slope For Roof Drainage

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.

Minimum slope for roof drainage.

How to use the calculator. Asphalt shingles continue to be the most widely installed roof covering option in north america. For household sinks the drain pipe diameter is often either 1 5 or 2. Asphalt shingles minimum roof slope roof pitch r905 2 2.

1 see sentence 9 26 3 1 2. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. Asphalt shingles can only be installed on roof slopes of 2 12 or greater. Toilet waste lines are often 3 or 4.

This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof systems in new construction. 3 profiled metal roof cladding systems specifically designed for low slope applications are. First figure out the diameter of the pipe you are working with. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

These considerations include the length of the roof the roofing material the size of the roof as well as the. This means that the rise of the slope goes up or down 8 inches for every 12 inches. Adding a roof can create drainage problems if the roof pitch is too shallow. Drain pipe slope calculator.

This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. 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. For standing seam metal roof panel systems a 1 4 12 minimum roof slope is prescribed. For metal panel roof systems with nonsoldered seams with applied lap sealant ibc 2018 prescribes a 1 2 12 minimum roof slope.

To put it in perspective the angle of this slope would be around 30 degrees. 2 see sentence 9 26 3 1 3. An example for a steep sloped roof is 8 12. The following diagram lays out the different terms that are used in the calculator.

The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.