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Community and Q&A

Has anyone experienced problems installing Hardi siding over Zip R ?

MhHgDg8rcv | Posted in Green Building Techniques on

I am building a “high performance” home in S E Dallas. I am concerened about Hardi siding staying attached, long term, when it is nailed through 1/2″ OSB with 1/2″ foam (Zip R). The siding will be blind nailed, properly. I have heard complaints by others that the nails worked loose due to expansion and contraction of the foam, causing extensive warranty issues for the builder. Having an extensive background in framing and general carpentry, I am doubtful of this zip R product in this situation. I would like to hear from anyone who has used this product in the manner described.
Phillip McCloud

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  1. Expert Member
    ARMANDO COBO | | #1

    I’ve raised several concerns with the Zip R panel here in DFW; however, siding attachment has never been one of those. The APA has approved the use of installing siding to framing members when rigid foam is between the framing member and the OSB/Plywood sheathing. I don’t believe there is an ICC-ES report on it. I would assume that screwing (not nailing) siding to the framing members with long enough screws (3”-4”) maybe enough. You may want to contact ICC, the APA or get an engineer report for your application. I imagine that if you intent to use a rain screen, that should be taking into account on the fastener as well. The APA has a few reports you can download about installing siding with rigid foam as sheathing.
    For what is worth, JH Best Installation Instructions do not address how to install their siding to the Zip R board, I imagine because is a new product. It wouldn't be a bad idea to call JH Tech Support and ask them about it.

  2. GBA Editor
    Martin Holladay | | #2

    You wrote, "I am concerened about Hardi siding staying attached, long term, when it is nailed through 1/2-inch OSB with 1/2-inch foam."

    You are nailing at each stud, aren't you? And you are using nails that are long enough to be firmly embedded in the studs, right?

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