Per NRCA, coal tar pitch can be used on slopes up to:

Per NRCA, coal tar pitch can be used on slopes up to:

• A. 1/16:12
• B. 1/8:12
• C. 1/4:12
• D. 1:12

Answer: (B)

Coal tar pitch is a low-slope, cold-applied roofing material, so it must be used where the roof doesn’t shed water quickly. The NRCA specifies a maximum slope for coal tar pitch of up to 1/8:12, meaning one-eighth inch of rise for every twelve inches of run. This keeps the material from flowing, thinning, or leaking on steeper surfaces and ensures proper adhesion and waterproofing. Slopes steeper than that (like 1/4:12 or 1:12) are not suitable, while shallower slopes (such as 1/16:12) are permissible but not the maximum limit. Therefore, the maximum allowed slope is 1/8:12.

Coal tar pitch is a low-slope, cold-applied roofing material, so it must be used where the roof doesn’t shed water quickly. The NRCA specifies a maximum slope for coal tar pitch of up to 1/8:12, meaning one-eighth inch of rise for every twelve inches of run. This keeps the material from flowing, thinning, or leaking on steeper surfaces and ensures proper adhesion and waterproofing. Slopes steeper than that (like 1/4:12 or 1:12) are not suitable, while shallower slopes (such as 1/16:12) are permissible but not the maximum limit. Therefore, the maximum allowed slope is 1/8:12.