How important is it to tape both layers of foam?
I am installing two layers of 1-1/2″ fiberglass faced poliso. I purchased some cheap tape that I had thought would make a good seal on the seams. However, now that we’ve put a layer on, it is obvious the tape isn’t going to do the job. So now I have a lot of left over tape and facing the fact of buying more expensive tape to do the job right.
How important that the interior layer of foam be taped? One thought I had was to put the cheaper tape on the inside layer and the good stuff on the outside layer. If the inside layer is tape just for redundancy, the cheap tape might be good enough?
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