Discussion Starter · #1 ·
Is it really necessary to use pressure treated lumber (vs. untreated) for build-up around the perimeter of the roof when adding insulating board under a membrane roof? I see architects always spec it out on commercial jobs, but Ive never known why. It should never get wet and to seems to me like an unnecessary additional expense. Besides, at least in ths area the treated lumber you purchase is pretty poor quality. Any thoughts?