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Flash foam and Roxul?

I understand from prior posts there are concerns with the flash foam and fiberglass insulation in terms of moisture vapor.

Would the use of proper barriers and Roxul instead of fiberglass help to abate that concern?

Asked by George Levicki
Posted Aug 29, 2014 10:58 AM ET
Edited Aug 29, 2014 11:45 AM ET


1 Answer

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Your question is unclear. The "flash and batt" or "flash and fill" technique works, as long as (a) you use closed-cell spray foam rather than open-cell spray foam, and (b) the foam layer is thick enough to keep the interior side of the cured foam above the dew point in January.

There is no technical reason why you can't use Roxul mineral wool insulation for a flash-and-batt job, but I don't think it would be particularly cost-effective. Other insulating approaches make more sense.

Answered by Martin Holladay, GBA Advisor
Posted Aug 29, 2014 11:43 AM ET

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