Thermax sturdiness?
Chris Simmons| Posted inEnergy Efficiency and Durabilityon
Hi:
My plan was to insulate my concrete basement wall with Dow polyiso Thermax boards without adding sheet rock covering. My understanding was that the white fiberglass side was sturdy enough to take moderate day-to-day contacts. However, my brother just informed me that his experience was that Thermax is not much different to regular foil-faced xps in terms of its durability. While I do not intend to play baseball in the basement and we have no kids, i would prefer to not spend $3K on insulation to have it look an eyesore in a few years. Would appreciate comments from members who have actually used this material and left it unprotected.
Thanks,
Chris
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Replies
Chris,
The reason that some jurisdictions allow Thermax to be left exposed, without being covered by drywall, has nothing to do with its resistance to physical abuse. It has to do with how well Thermax behaves in a fire test.
Thermax is insulation, and it is not designed to look good. The reason you may want to spend $3,000 to install Thermax is to save energy and to make your house more comfortable, not to look good.
If you are worried that you may find your Thermax to be an eyesore, I strongly advise you to cover whatever insulation you decide to install with gypsum drywall, paperless drywall, or cement backerboard covered with a skim coat of drywall compound.
Thanks, Martin. The reason for considering Thermax was exactly your point about it being OK left exposed without drywall covering because of its fire characteristics. But if it is not really able to withstand minor abrasions etc and is fragile during handling, then it does not seem like the optimum (expensive) solution that I thought it was. Not really interested in studs and sheet rock for this location.