Going to be building a 17’x20′ shed in Norther Virginia. Was planning on building the foundation using solid concrete blocks set on 4″ of gravel. But,….have read a couple of articles that says concrete block foundations work for small to mid sized sheds, and anything over 200 sq/ft should use a post/pier foundation. I’d rather keep to the solid concrete block to keep it simple and I already have the block. Thoughts?
For the rest of the shed flooring I’m looking at setting 4×6 PT beams on the block. The floor would be 2×6 PT joists 12″ OC sitting on the block. Floor sheathing will be two layers of 3/4″ OSB.
Thanks,
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Depends on the soil and drainage. On well-drained, stable soil you should be fine.
You do need to tie things together well, or otherwise the shed will slowly creep off the block.
Permit Required?
In most locations you need a building permit for anything over 200-sf. That is why at 200-sf you have to have a real foundation.
So, I'd ask the AHJ, what the requirements are. They may have minimum standards.
If no permit is needed, I just throw a few old railroad ties on the ground and go from there.
Have just used old car wheels filled with mud also.