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Community and Q&A

ZIP Sheathing / Hardie Lap Siding

jdchess | Posted in General Questions on

New construction in CZ3. Single story house with 9′ ceilings throughout. Exterior walls are 2×6 @ 24″ OC with dense pack cellulose, ZIP sheathing, and Hardie lap siding.

My intention is to use the ZIP Long Length sheathing (10′ 1.125″) installed vertically. The sheathing would cover a 9′ wall plus a 12″ raised heel truss from top to bottom with no horizontal seams or blocking. This seemed nice, clean, and simple. Seemed like a good option, but the local Huber rep mentioned that he thought the 7/16″ ZIP installed vertically on 24″ centers would be wavy. I called Huber and a tech support rep told me that the 7/16″ should be fine installed vertically on 24″ centers with no waves or distortion.

So I’m not sure what to believe exactly. Anyone experienced this? Any thoughts or input would be greatly appreciated.

I imagine that this could cause issues with the Hardie lap siding install which would show any waves in the sheathing. Correct?

On a slightly different note, I’m considering a rainscreen using 1x furring. This would move the siding away from the sheathing. Would this solve any potential wave issues in the siding install if the sheathing was in fact wavy?

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  1. Expert Member
    Akos | | #1

    The bigger issue with wavy siding is making sure you crown your studs correctly. This will make a bigger difference than the thickness of the sheet. OSB tends to be quite flat, so as long as your studs are good, you won't have any issues.

    Besides the extra wall drying benefit, a rain screen most painted siding last longer. Just make sure your siding is rated for 24OC nailing, not all are.

  2. Patrick_OSullivan | | #2

    > Seemed like a good option, but the local Huber rep mentioned that he thought the 7/16″ ZIP installed vertically on 24″ centers would be wavy.

    Take a look at @awesomeframers (Tim Uhler) and @pioneerbuildersinc (Bryan Uhler) on Instagram. Bryan posts here sometimes. They frame 24" on center and use 7/16" Zip.

    Tim has been on multiple webinars discussing advanced framing (including 24" on center):

    Tim challenges people to be able to identify his 24" OC wall from his 16" OC on the interior. I can't speak for him, but I suspect he'd issue the same challenge for exterior walls.

    To wit: you should be fine with 24" OC with 7/16" Zip.

  3. jdchess | | #3

    Akos and Patrick,

    Thank you guys for the replies. Point well taken about crowning the studs. Thanks for heads up on Tim and Brian Uhler. Very interesting guys.

    I felt like it should be fine as well but the conflicting info had me puzzled. Yeah for some reason, the rep felt that running the 7/16 ZIP horizontally wasn’t an issue at all on 24” centers but that the 7/16 long length 10’-1 1/8” sheets installed vertically would be an issue especially without any horizontal blocking. But even installed vertically on 24” centers each sheet is hitting three studs. Maybe there’s an issue with the strength of the vertical vs the horizontal axis.

    1. Patrick_OSullivan | | #4

      Oh look, a JLC article from Tim covering vertical vs. horizontal:

      It even has a picture of vertical 7/16" Zip. :-)

      1. pioneerbuilders | | #5

        I was looking up something else and came across this. Check the APA when it comes to sheathing ratings/orientation/nailing pattern as well as your structural engineer (if you have one). We've had problems with buckling albeit rarely. Acclimate your panels before installation, if you can. Furring strips will likely follow your sheathing plane, so that probably won't help you out. Raking light will accentuate any visual problems. Hope this helps.

  4. andy_ | | #6

    The buckling can and does happen. Ask me how I know :(
    I've built 24" OC and 16" OC, and they were both fine. Couldn't tell the difference...till this last one. Granted, weather was an issue and the wall got wet a lot during the shutdown but the buckling is noticeable on this one 24oc wall and not on any of the 16oc walls.

    1. andy_ | | #7

      I should add that I am not anti advanced framing. Just now that I've been burned once I'm hesitant to use it on a 9' wall that doesn't have opportunity for blocking.

      1. pioneerbuilders | | #8

        We've been there. Don't hesitate to reach out to Huber. Pay attention to the stamp on the inside for determining the manufacturing lot.

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