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Community and Q&A

Injection foam?

dbernard | Posted in Energy Efficiency and Durability on

I will be residing my house in the spring with vinyl.

The house is a 20-year-old gambrel, about 3,200 sq. ft., with 2×4 walls with fiberglass insulation.
I have already gone through the Efficiency Maine program, with air sealing and dense-packed cellulose in the attic. I did notice a big difference.

The house sits up on a ridge and gets a lot of wind.

Would it be worth the investment to inject foam into the walls from the outside? I currently heat with a wood boiler and baseboard heat and use about 5 cords of wood.

Thanks for your input or suggestions.

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  1. GBA Editor
    Martin Holladay | | #1

    Injection foam is a tricky product to use, and can cause plaster walls or drywall to blow out (bulge or crack).

    The standard way to insulate the empty stud bays of an older house like yours is with dense-packed cellulose. This work will be easy to perform as part of your re-siding job. It will be easy to drill holes in your wall sheathing from the exterior at that time.

    Any time that you are installing new siding, you have a once-every-50-years opportunity to install rigid foam on the exterior side of your sheathing. Don't waste this rare opportunity! I strongly urge you to consider including exterior rigid foam under your new siding.

    Here are links to two relevant articles:

    Roofing and Siding Jobs Are Energy-Retrofit Opportunities

    How to Install Rigid Foam Sheathing

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