What is the minimum design slope for liquid-applied roofs according to the Florida Building Code?

What is the minimum design slope for liquid-applied roofs according to the Florida Building Code?

• A. 1/8:12
• B. 1/4:12
• C. 1:12
• D. 0:12

Answer: (B)

A fundamental requirement for liquid-applied roof systems is to have enough slope to avoid water ponding and ensure proper drainage. The Florida Building Code specifies a minimum slope of one-quarter inch per foot of run (1/4:12), which is about a 2% grade. This small but consistent incline helps water move toward drains and prevents standing water that can degrade the membrane or lead to leaks. A completely flat surface (0:12) would fail to meet drainage requirements, and a slope of one-eighth inch per foot (1/8:12) is below the minimum and could still pond water. A slope of one inch per foot (1:12) is steeper than needed to meet the minimum and would satisfy drainage, but it is not the minimum required by code. Therefore, the smallest slope that meets the code is one-quarter inch per foot.

A fundamental requirement for liquid-applied roof systems is to have enough slope to avoid water ponding and ensure proper drainage. The Florida Building Code specifies a minimum slope of one-quarter inch per foot of run (1/4:12), which is about a 2% grade. This small but consistent incline helps water move toward drains and prevents standing water that can degrade the membrane or lead to leaks. A completely flat surface (0:12) would fail to meet drainage requirements, and a slope of one-eighth inch per foot (1/8:12) is below the minimum and could still pond water. A slope of one inch per foot (1:12) is steeper than needed to meet the minimum and would satisfy drainage, but it is not the minimum required by code. Therefore, the smallest slope that meets the code is one-quarter inch per foot.