Smith Roof Drain Optional Variations — Underdeck Clamp
Underdeck Clamp (-C)
The underdeck clamp should be specified on all but poured-in-place installations. Roof drains must be firmly secured to the roof with an underdeck clamp. Otherwise, due to snow loads, rain loads, and regular expansion and contraction, the drain will work in and out of the roofing, causing roofing membranes to flex and fail. Brittle tar will crack and leaks will occur.
"L" Shaped Underdeck Clamp (-CL)
A "L" shaped underdeck clamp (-CL) is available for use when the regular underdeck clamp is not acceptable.Specify the "L" shaped underdeck clamp when the deck thickness is less than the minimum dimension shown for the regular underdeck clamp. This is particularly applicable for roof drain installations in metal roof decks.