Osb vs plywood decking?

Discussion in 'Roofing and Siding' started by bryce, Aug 7, 2014.

  1. Aug 7, 2014 #1

    bryce

    bryce

    bryce

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    Is it better to use
    OSB
    5/8 4x8 Oriented Strand Board Tongue and Groove 19/32

    or
    3/8 inches 4 ftx8 ft Standard Spruce Plywood

    for decking?

    Is the tongue and groove structural, so it doesn't have to be supported at the edge?

    I'd like to use the osb but have been told it swells?
     
  2. Aug 7, 2014 #2

    nealtw

    nealtw

    nealtw

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    Depending on the deck you have in mind. Tongue and groove is for supported edges and is for the floor. Adventech (looks like osb) makes a nice floor inside. We get 3/4 adventech or 5/8 plywood depending on the owner and layout of the joists. For an exterior deck that will be covered with waterproof membrane we use sanded plywood 3/4 or 5/8, sanding does make it thinner.
    Adventech is waxed so it doesn't swell with water and plywood will.

    Roof deck, 7/16 osb is good for rafters up to 24" on center. Use 1/2 inch "H" clips between the sheets when the space between rafters are more than 16 inches.
     
  3. Aug 7, 2014 #3

    bryce

    bryce

    bryce

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    I think i better use 1/2" plywood at $23 a sheet.

    I have a problem now because i had old 3/4 plywood and have used that for the decking on one side and have to buy another 10 sheet to finish that side $35 a sheet. oooch. Then use the 1/2" on the other side.
     
  4. Aug 7, 2014 #4

    nealtw

    nealtw

    nealtw

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    Osb is better for walking on , ruf side up.
     
  5. Aug 7, 2014 #5

    bryce

    bryce

    bryce

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    I was reading you should leave it outside for a month to gas off before installing osb or you will get toxic chemicals. Gotta feel sorry for those HD workers...

    I'm working with a roofer guy now. He thinks 3/8" plywood is okay, but it is 24" centers, better 1/2" i think. It's worth paying this guy because he works 3x as fast as me.

    I guess you could notice 1/4" difference from one side of the roof?
     
    Last edited: Aug 7, 2014
  6. Aug 7, 2014 #6

    nealtw

    nealtw

    nealtw

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    Outside sheeting and roof sheeting is outside the vapour bearier so off gasses don't count for much and the glue is very close to the same glue in plywood.
     

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