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roof sheathing

  1. A

    APA Span tables remarks

    They are engineered I get it, but APA span tables for sheathing - 7/16 live load of 40 psf vs 15/32 is 70 psf. pretty much 1/32" gets you 30 more psf? Seems a bit crazy to get 75% more load out of 1/32." Its engineered but I find that hard to believe. I am returning my 7/16 osb because I...
  2. A

    R503.2.1.1(1) code on roof sheathing thickness

    Am I reading it right that if I have 60psf snow load in my area (thats what trusses are engineered for), I could not use 7/16 osb because that only allots 40psf with 24" O.C? I would have to use 15/32 plywood they dont sell 15/32 osb where I am at, or 19/32 OSB? I will probably go with 15/32...
  3. R

    Roof Sheathing Thickness

    My state uses the 2015 IRC. There has been substantial debate over the minimum acceptable thickness of plywood when used as roof sheathing. There has been a lot of mis-quoting of the wrong section of the code. After research I believe that you have to get to Table R503.2.1.1 which show that...
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