[David]

I'd like to build a portable building behind my garage. Per city code it has to 120 sqft or smaller and portable. I wanted to put it on a concrete slab, but it'll be over a utility easement and after getting all the underground stuff marked, I found there's a gas line right under where the building will go.

I thought about a flat (no beams) concrete slab with a couple of tow eyes at the ends so I could call it portable, but I think a 4000 lb slab would be hard to define as portable.

It looks like the most common way to go is 4x4 or 4x6 treated skids placed on concrete pads with 2x6 floor joists on top. I can go this way, but I really don't like having what'll be close to a 12" foundation.

Does anyone out there in Pelican Land have any better ideas?