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Plywood Panels Over XPS Insulation

derms | Posted in Energy Efficiency and Durability on

Can I attach T1-11 panels directly over xps or do I need to create a drainage plane between them.  This is for a seasonal cottage in a ‘cold’ climate.

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  1. GBA Editor
    Kiley Jacques | | #1

    Hi Richard,

    I’m giving your question a bump. What you describe (without a drainage plane) sounds essentially like what Martin Holladay covers in this article: Nailbase Panels for Walls. I’m guessing most green builders would advocate for creating a vented rainscreen, if possible. Anytime there is an opportunity to move bulk water away from the structure and improve its drying potential, that is the best course.

    1. derms | | #2

      Thank you! I'll likely go with a vented rainscreen as the process would be easier anyway if I used battens to secure the xps before putting on the T1-11. I'll check out Martin's article that you linked. I was a little surprised not to find the sort of straightforward answer you provided even from the APA.

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