A 10,000-square-foot commercial roof uses a single-ply membrane. Under 2021 IBC 1507.12.1, what minimum design slope is required for drainage?
- A1/8 inch per foot
- 1/4 inch per foot
- CZero slope
- D1/16 inch per foot
Where to look it up
https://core-docs.s3.amazonaws.com/documents/asset/uploaded_file/3836/Lennox/3042180/2021_International_Building_Code.pdf
Why B is correct
Single-ply membrane roofing requires a 1/4-inch-per-foot design slope. Roof area does not select a different minimum under this provision. Source: 2021 IBC 1507.12.1; https://core-docs.s3.amazonaws.com/documents/asset/uploaded_file/3836/Lennox/3042180/2021_International_Building_Code.pdf