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After a fire

johnsalazar | Posted in General Questions on

Hi guys. Two months ago we had a fire in our home. While the fire was contained to the basement the remainder of the house suffered extensive smoke damage. Part of the upcoming process is removing all perimeter drywall and insulation. Then they will be cleaning the framing and sheathing and sealing it with an oil based sealer. 

My concern is the sealing. Living in Chicago we have our vapor barrier which in my case is simply a kraft faced insulation on the inside. I am concerned about the long term effects of having the walls sealed on the cool side of the insulation and then the fact that the kraft paper will further slow down the drying process. The insurance company will provide a five year warranty but I believe that any ill effects of this process won’t be appearant for 10 plus years. 

I am trying to get them to pay $6k more for closed cell spray foam to completely stop the transfer of vapor through the wall (and attic rafters) but need help in proving that my theory is scientifically sound. 

I would greatly appreciate any ideas, tips, links, etc that could help me convey the need for this to the insurance company. 

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Replies

  1. MattJF | | #1

    What is the published perms of the oil based sealer on a wood surface? There aren't many products that actually maintain low perms on wood unless they have significant build up. Is this standard practice for smoke remediation?

    Instead of kraft face batts, I would use Membrain, detailed as best as possible as an air barrier. I think this would seal up your wall better for any residual smells. You could use ocSPF in the walls to improve air sealing.

    Are the attic rafters going to be insulated or the attic floor? If the rafters are insulated, will it be vented or unvented? If unvented use ccSPF.

    See this article concerning ccSPF: https://www.finehomebuilding.com/2017/07/10/closed-cell-foam-studs-waste

  2. johnsalazar | | #2

    Hi Matt, thank you for your response. They are going to use a Kilz type primer. This is standard from, what I understand. When I look at the SDS for KILZ RESTORATION is states Vapor Pressure: as Not applicable. On their KILZ Original Interior/Exterior Primer shows the same. My guess is they don't test for vapor.

    In the attic they want to insulate the floor with batts but the actual trusses and sheathing will all be sealed with the kilz. ( I think this is my biggest concern)

    If I can get them to use spray foam the trusses being only 2x4's would be completely encased as the spray foam would be 6" thick so unvented.

  3. MattJF | | #3

    Vapor barrier paints seem to generally run around .4-1 perm in the lab. Turns out they are not that way in the real world:
    https://www.greenbuildingadvisor.com/article/joe-lstiburek-discusses-basement-insulation-and-vapor-retarders

    I would still go for membrain and an airtight drywall approach.

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