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Is Rmax Thermasheath-XP an acceptable alternative to Dow Thermax?

NatePa | Posted in Building Code Questions on

I intended on using Dow Thermax for an exposed basement application in a residential setting.

I thought there were no alternatives without using an ignition barrier (drywall) but recently came across Rmax Thermasheath-XP. For my purposes, I believe this would be a more affordable option.

Does anyone have any experience with this product? It seems to have similar properties to Dow Thermax. Does Dow Thermax have any documented advantages?


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  1. GBA Editor
    Martin Holladay | | #1

    According to the manufacturer's claims, it should work. But check with your local building inspector before you buy the materials -- just to make sure your inspector agrees.

  2. mackstann | | #2

    All of the polyiso manufacturers seem to have an equivalent product.

    Some others I've found:

    R-Max TSX-8500 & TSX-8510
    Johns Manville CI Max
    Hunter xci 286

    but they seem to be even harder to source than Thermax, which is probably why they aren't mentioned much.

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