Single slope roof - how to attach rafters

Discussion in 'Coop & Run - Design, Construction, & Maintenance' started by Hillia, Apr 11, 2014.

  1. Hillia

    Hillia Hatching

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    So...we're working on our 8x12 coop. We got the floor done (with some help from the forum!) and we're now debating the roof. We want a single slope roof going from 8' to 6'. I've seen pictures using 2x4's, will that be sturdy enough? We do get snow but never more than a few inches at a time, so I'm not too concerned about that load. And I've been reading about notching the rafters to fit on the top plate vs using rafter hangers. Neither of is is terribly handy, so I'm a little concerned about cutting notches and getting them lined up properly.
     
  2. smcgill

    smcgill Chirping

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    Last edited: Apr 11, 2014
  3. Hillia

    Hillia Hatching

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    Oh, that's excellent! My Google-fu was not working so I kept getting very complicated instructions for residential-type applications. Thank you!
     
  4. leifjohnston

    leifjohnston Hatching

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    I suggest you are trying too hard. Anything the small scale that you are building can be nailed together or stronger still use wood screws. You can angle the nail or screw to pull the pieces together and it should be fine.
     
  5. blucoondawg

    blucoondawg Songster

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    This is not entirely accurate, if you look at these brackets you will see these brackets are for use either with trusses, which set flat on top of the wall anyways, or rafters which have also been notched (birdsmouthed) to set flat on the wall. Now you could use these without notching but it won't be "right" and also not as strong as doing it properly as the rafter would only be contacting the wall at a very small spot.

    I built mine 12x12 with the same roof design you are going for I used 2x6s at 24" centers, but we get a lot of snow. If using 2x4s I would go to 16" centers for added strength.

    Figuring out how to cut the notches can be tricky, I found it easiest to do by actually drawing out a full scale picture on the coop floor, I drew out the 8 ft wall on one side and the 6ft wall on the other side, then I laid one of my rafters across the picture where it would go in reality and marked out the notch, I then cut the notches and made sure the rafter fit, then I used that rafter as a pattern to cut all the others.

    They do make a metal bracket for use in engineered lumber called i-joists which is meant to fasten an un notched rafter but they maybe a sort of specialty item and harder to find I'm not sure as I've never used them
     
  6. smcgill

    smcgill Chirping

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    [​IMG]
    one good example is above. and a closeup below you are right "blucoondawg"it showes trusses. But
    If you did not have the horizontal piece from the truss, it's the same as a 2x4 on edge.
    [​IMG]
    In the above closeup you would use the bracket below.
    [​IMG]
    I hope this helps alittle.
    Sean
     
  7. blucoondawg

    blucoondawg Songster

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    My point is it is a truss and you do have a bottom cord which is allowing the truss to sit flat upon the wall, if the truss didn't have the bottom cord it would then not be a truss but a rafter which would have the birdsmouth notched in to allow the roof load to be distributed on the wall. If you simply set an unnotched rafter on top of a wall the pressure being exerted on the wall by the weight of the roof will want to push the walls over rather than putting the loads straight down so the walls can hold them up.

    The metal brackets you are showing in the pictures are not meant to fasten your rafter to the top of your wall, these brackets are called hurricane clips and are required by building code in some areas to add additional strength in the case of severe wind storms. The proper way would be to notch the rafter as well as use the clips but in a chicken coop application a notched rafter as good enough.

    If you look further through the pictures in the link you will find some that do use rafters and you will see that they also have the notch cut, not doing so makes for a weak structure.
     
  8. Blooie

    Blooie Team Spina Bifida

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    My Coop
    Those are what we used. Neither of us are carpenters....between the two of us we couldn't stack a straight sandwich!

    [​IMG]
    8 foot roof sloping to 6 feet

    [​IMG]
    Almost finished.....just need to add the vents in the soffit, finish the trim and painting it, and setting up the permanent run so the girls (and Charlie) don't need to use the temporary one any more.
     
  9. blucoondawg

    blucoondawg Songster

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  10. mpruett

    mpruett In the Brooder

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    It looks great!
     

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