Tape for Foil-Faced Foam Board Seams
h4x
| Posted in General Questions on
Good afternoon everyone,
We will be installing foil faced foam insulation for our roof which will be acting as a radiant barrier. I’m having a hard time finding a foil tape that is rated for use in this application. Specifically, we’ll be using Halo Exterra insulation, and they recommend a few different tapes for sealing seams on their boards. Unfortunately, I’m unable to procure the Halo branded seam tape. Some of the other tapes I have found are not for use in roof assemblies. In a worst-case scenario, I’ll just use an approved non-foil seam tape. Anyone have a recommendation?
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Replies
Nashua 324A. Home Depot stocks it. Works great, and not too expensive. I've used it to tape foil faced polyiso many times. I did have an issue once with some kind of oil film on the polyiso that made the tape not stick very well, but I was able to wipe it off with isopropyl alcohol and then the tape stayed stuck.
Bill
Thanks Bill,
My biggest concern was in the longevity of a tape being used in a roof assembly...however, the operating temp for the 324A maxes out at 325* F, which seems reasonable. I know that one of the tapes I was looking at (I forget the brand) had a note from the mfg that if used in a roof assembly, over time the tape would wrinkle and bunch up, thus causing issues...very specifically, they said DON'T use in a roof. This was due to the adhesive that they were using (some sort of rubberized asphalt). This Nashua has an acrylic adhesive that should withstand that.
I'll throw a second vote for the Nashua tapes on the foil facers. It's not coming off, without part of the insulation at least. Just roll it like all the other tapes.
Thanks, I appreciate the feedback!