Foundations for 6inch block for a shed.

session savage

Im building a small shed (15' x 10' ish) I am building it out of 6" block. Its only going to be 8' high with a lean to roof.

Half the length of one wall and the full lenght of another wall will be laid directly onto an existing 7" thick concrete base (I am building a block shed to replace a steel one and I'm increasing the floor space) and the rest of the walls will be build on a foundation.

Do these foundations have to have steel in them? (the ground is solid slig) and are there any issues I should address with the portion of wall being build directly onto the existing pad? I cant dig a foundation around the existing concrete pad as there is no room.

Thanks fo any suggestions.

Martron

rule of thumb is that a foundation need to be 3 times the width of the wall.

you wont need steel if the foundation is need unough on good ground.

i would try and tie the slab into the new foundation some how. dowel in steel bars to stop differential settlement and cracks possibly forming in the wall.

paddy147

A bit of steel mesh/rebar in the foundations is no harm at all.

Thats what my builder did when building my garage.Also rebarred and insulated the garage floor aswell.

nophd08

You wont have any problems building without foundations.
I built my own shed with 6" blocks directly on top of floor slab which is 5" thick.
As paddy said steel is no harm if you want to tie into existing floor.
For peace of mind, but not necessary you can dig an inch or two deeper just under where blocks will sit so you'll have an extra bit of strength.
I presume you're using ready mix for your floor.?

harry21

Absolutely, you can get away without steel if the ground is anyway stable. In the old days in the 1800's they built up to 2 storeys and the foundation would be made of brick on the subsoil.

You are not goiung to have a problem. Steel in the bottom increase the tensile strenght along the lenght of the foundation. An 15' wall won't be a problem.

Obviously, from a technical point of view it is incorrect, but in reality it won't fall down or crack either.

CoalBucket

Agree with above 450mm should suffice, steel not essential as long as the ground conditions are good. If it was mine though I'd put a bit of re-bar in though. For the size of the shed it would cost very little. Btw i'd also dowel into the existing base and tie the two foundations together.

session savage

Thanks everyone, thats savage stuff. Itll be a beast of a shed.