When installing a ring-clamp drain on an insulated roof, how do you cut the insulation?

When installing a ring-clamp drain on an insulated roof, how do you cut the insulation?

• A. Taper the insulation back at least 18 inches
• B. Cut straight
• C. Cut at an angle
• D. Leave insulation as is

Answer: (A)

When installing a ring-clamp drain on an insulated roof, you want the insulation around the drain to be tapered back to create a smooth, sloped surface toward the drain. Cutting the insulation back at least 18 inches provides enough space for the drain assembly to be flashed properly and for the roofing membrane to hug a gradual ramp rather than sit on a sharp edge. This taper helps water flow toward the drain, reduces the risk of moisture trapping under the ring clamp, and allows the membrane to seal cleanly around the drain. Cutting straight, cutting at an angle, or leaving the insulation in place would leave a abrupt step or flat surface around the drain. That can hinder proper drainage and flashing, increasing the likelihood of leaks or sealing difficulties around the drain.

When installing a ring-clamp drain on an insulated roof, you want the insulation around the drain to be tapered back to create a smooth, sloped surface toward the drain. Cutting the insulation back at least 18 inches provides enough space for the drain assembly to be flashed properly and for the roofing membrane to hug a gradual ramp rather than sit on a sharp edge. This taper helps water flow toward the drain, reduces the risk of moisture trapping under the ring clamp, and allows the membrane to seal cleanly around the drain.

Cutting straight, cutting at an angle, or leaving the insulation in place would leave a abrupt step or flat surface around the drain. That can hinder proper drainage and flashing, increasing the likelihood of leaks or sealing difficulties around the drain.