clarification on types of Thermax and fire rating
I live in climate zone 6a (coastal Maine). I am wanting to install insulation in my crawlspace because it currently is uninsulated. I was able to find some second-hand Thermax insulation, which is my preferred choice because I would rather not have to put drywall over the insulation.
The second-hand Thermax in question is metal building board. I found this document from the state of Maine (https://www.maine.gov/future/sites/maine.gov.dps.fmo/files/inline-files/plans/documents/Thermaxletter.pdf) saying that only Thermax sheathing and white finish products have been approved for use without a thermal barrier. I had been under the impressing that all Thermax didn’t need a thermal barrier. Is that not the case? The product specification says that it can be exposed to the interior without a thermal barrier and is class A fire rated (https://www.dupont.com/content/dam/dupont/amer/us/en/performance-building-solutions/public/documents/en/thermax-metal-building-board-nh-pis-43-d100095-enus.pdf).
I contacted my town’s building department for clarification, and they didn’t answer my question, telling me that they don’t enforce the Maine Uniform Building and Energy Code, which includes the 2015 IRC. So it sounds like no one is going to check? I just want to make sure that I’m putting safe insulation in my house. Is Thermax metal building board as safe as the other “approved” Thermax products?
Can anyone provide clarification on this?
Thanks for your help.
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