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Attached garage wall detail 2×6 vs 2×4

Adam Peterson | Posted in Energy Efficiency and Durability on

Building a house next Spring in Northern IL (climate zone 5). We are using 2×6 wall construction and hoping to do 2″ of XPS on exterior.

We got our plans back and they show 2×6’s on the perimeter for the house and attached garage, 2×4’s interior.

The one wall I was wondering about was the wall between the attached garage and the house. The plan shows this wall as a 2×4.

Is there any reason this wall shouldn’t be 2×6?

Do I insulate this wall as I would an exterior wall with 2″ of XPS on the garage side?

Even if the garage is insulated it’ll still be colder than the conditioned space in the winter due to leaky garage doors and lack of insulation below garage floor…right?


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  1. GBA Editor
    Martin Holladay | | #1

    The wall between your house and your attached garage is an exterior wall. It should be framed with 2x6s and insulated like all of your other exterior walls. On the garage side, the wall should be finished with 5/8 inch drywall, not 1/2 inch drywall, for fire safety reasons.

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