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Seal (without insulating) rim joist?

1940House | Posted in Energy Efficiency and Durability on

Hello,

I’ve got a crawlspace in a 1940 home that is reasonably warm and dry, but I want to seal against airflow and spiders. Is it crazy not to insulate as well?

I feel like I can get the sealing done now, and might insulate at a later date.

If I go this route, what is best for sealing the sill plate and rim joist (not sure if I’m using those words right…)? Caulk only, or Great Stuff? If I use Great Stuff I imagine the process being easier — it’s a tight crawlspace — but I’m not sure if that works as well.

The other concern is if Great stuff will get in the way of future insulation (I’d probably use rigid foam and re-seal around the edges — but insulating might not ever happen).

Thank you for any input.

(for a photo, the idea is to do this: http://www.familyhandyman.com/basement/insulate-basement-rim-joists/step-by-step, but without the rigid insulation at this point — I’m thinking caulk or Great Stuff only)

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Replies

  1. GBA Editor
    Martin Holladay | | #1

    Firsty,
    It certainly makes sense to seal air leaks. You can insulate later if that's how you want to do it.

    I would advise you to use a high-quality caulk (like a polyurethane caulk).

    If you decide that you want to go ahead and insulate, here are links to articles that explain what you need to know:

    Air-Sealing a Basement

    Insulating rim joists

    Basement Insulation

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