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Is an exterior curtain wall retrofit more plausible than removing clapboard siding & installing ply sheathing before rigid foam installation?

adzitelli | Posted in Green Building Techniques on

The curtain wall retrofit would include placing 2X4’s vertically against the clapboard siding spaced 24″ on center; then filling the 3.5″ cavities with spray foam or cotton batts, followed by installing two layers of 2″ polyiso rigid foam panels over. Finally, replace the vinyl siding over the rigid foam.

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  1. GBA Editor
    Martin Holladay | | #1

    I'm not sure what you mean by "more plausible." Your suggested method is doable, but it won't be cheap -- especially if you use spray foam.

    If you want to read more about two retrofit jobs that took the approach you are suggesting, you can read about them here:

    Brand New Appearance and Performance for An Older Duplex

    Deep Energy Makeover: One Step At A Time


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