1/2" OSB or 3/4" OSB for roof?

Discussion in 'Coop & Run - Design, Construction, & Maintenance' started by Wxguru, Oct 13, 2014.

  1. Wxguru

    Wxguru Chillin' With My Peeps

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    Going to be taking care of the roof for our new coop this week. I have a roof that is going to be about 10'X8'. That will leave a 13" overhang on each side, and about 22" front to back (lean to style). Frame will be using 2x4x8's and 2x4x10's with approximately 8 rafters in there. I will lay down the OSB sheets, and then a 15LB asphalt roof sheet and then shingle the roof as you would a normal roof (slope will be about 2.5/12). Rafters will be attached with hurricane straps.
    With that being said, would I be alright going with 1/2" OSB or do I need to go with 3/4" OSB? Trying to keep some of the weight down a bit but maintain strength and keep from any compromise.
    Also, necessary to use PT or can I go with studs?
    I do plan on putting a drip edge, and gutter on the back as well and drain water away from the coop (it is a sloped area).
    Thanks for all the help!!
     
  2. mississippifarmboy

    mississippifarmboy collects slightly damaged strays Premium Member

    You only need PT lumber if it's in contact with the ground. And personally I'd rather use 1/4" plywood as 3" OSB. But that's just me, I hate the stuff.

    If the rafters are 16" OTC I'd say 1/2" would work though.
     
  3. chicksurreal

    chicksurreal Chillin' With My Peeps

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    We used 3/4" OSB for ours, but our coop is pretty big and we didn't want any sagging, so we thought supports every two feet on center and 3/4" OSB would work. We are also using asphalt shingles.
     
    Last edited: Oct 13, 2014
  4. Wxguru

    Wxguru Chillin' With My Peeps

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    My rafters will be on 20" center....and asphalt shingles.....I might split the middle and go 1/2". 1/4" just seems so thin
     
  5. chicksurreal

    chicksurreal Chillin' With My Peeps

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    Yeah, I think 1/4" would be flimsy. That's my uneducated opinion.

    We are glad we went with 3/4", but we probably could have used 1/2" with no problem. Our roof is 16' x 10' and we wanted to make sure it would hold up.
     
  6. MeepBeep

    MeepBeep Chillin' With My Peeps

    Since you are in Arkansas and don't have to factor in a a heavy snow load you will be plenty fine with 1/2" OSB sheeting on the roof, with up to 24" rafter spacing no problem, surprisingly 1/2" OSB on 24" centers is actually snow load rated and up to code in many places... Do note though, you might see some bow in between the rafters, but this is common in this application, and because of this to avoid one sheet bowing and the other not creating a gap, you can install panel clips (H clips) in between the rafters to help avoid this by tying the two sheets together, it's standard practice and code in most areas to do so...

    http://www.menards.com/main/tools-h...ements/miscellaneous/plywood-clips/c-8874.htm
     
    Last edited: Oct 13, 2014
  7. Wxguru

    Wxguru Chillin' With My Peeps

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    Any issue with 22" overhangs on front and back? Sagging concern? Want to find out now, rather than when it happens and I have to come up with a new plan.
     
  8. MeepBeep

    MeepBeep Chillin' With My Peeps


    Are they supported overhangs aka are the rafters extending out that far as well? 24" overhang is normal for modern house/garage construction...
     
  9. Wxguru

    Wxguru Chillin' With My Peeps

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    Rafters will go the full distance to the actual roof frame....attached....
     
  10. MeepBeep

    MeepBeep Chillin' With My Peeps

    Frame your overhangs like this and you won't have any issues, even at 24" spacing with 1/2 (or even the cheaper 7/16) OSB...

    [​IMG]
     

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