Suggestions on sonotube size for a 12' x 20' shed on unlevel ground
I'm thinking about putting up a 12'x 20' shed. The ground where it is going is sloping and (at this point anyway) very uneven.
I was thinking about using Sonotubes for the footings (the shed will be built on 4x4 pressure treated runners). I was thinking about using 4 or 5 tubes per runner (w/4 runners total).
What size (diameter) Sonotubes would you recommend I use?
Any help is appreciated