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16″OC for joists & 24″OC for walls

skibow | Posted in General Questions on
Project details: I’m trying to build a 13.5′ tall, 10′ wide x 28′ long tiny house on a trailer that’s 8′ wide, meaning the house will overhang on either long side of the trailer by 1 foot. I’m hoping to use 24″ OC wall stud spacing, but fear I’ll need to use 16″ OC floor joist spacing. This means that for every floor joist/wall stud that line up, there are two in between that don’t. I could of course use 24″ OC floor joist spacing, but might have to upsize the lumber such that I lose too much interior headroom – I want to find an acceptable balance. Roof construction will be rafters with a ridge board (non load bearing). I expect to use 2×8 rafters spaced 24″OC to withstand a uniform load of ~60psf (10psf dead load + 50psf snow load).
 Is the two different spacings between wall studs and floor joists OK given the 1 foot overhang?
Thoughts, questions? I’m happy to clarify/elaborate on the project.
Thank you

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  1. Expert Member
    Michael Maines | | #1

    Offsetting the studs from the floor joists should be fine; the rim joist will distribute the load the few inches needed.

    Have you read up on Department of Transportation requirements where you'll be traveling? In my state, trailers can't be wider than 8'-6" and if they have a wider load they need an escort vehicle.

  2. skibow | | #2

    Hi Michael, thanks for the reply! I’m glad to hear that, I figured the rim joist might help.

    I have been researching the DOT regulations and it sounds like an oversize permit is needed for over 8.5ft, but not escort vehicles until you get well over that, usually 12-15ft depending on state- I am going to be well under that.

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