Foundation depth for non loadbearing block wall

[pilsbury]

My extension is in 2 parts:

Side kitchen extension, single storey which will have trench fill foundations 600mm wide and approx 1m deep for regular block cavity wall. No problems

Partial garage conversion, where the rear half of the garage is converted to a utility and WC. I was thinking to maximise space doing a single skinned block wall with celotex, VCL and plasterboard internally, or a timber framed stud wall built off block up to DPC. What foundations would likely need to be dug for this? Full 1m trence fill again?

 

[tomfe]

Is there already a slab down?
A stud wall would not need foundations.

 

[^woody^]

I was thinking to maximise space doing a single skinned block wall with celotex

You can't use all those words in the same sentance. I'm not feeling the concept of maximising space by building a 230mm thick wall.

A 100mm timber wall can be built off the floor, or two course of engineering bricks if there is a raised floor on the habitable side.

 

[pilsbury]

Thanks for the replies. I could have been clearer. Slab that is currently the garage floor is pretty crap. Approx 30cm lower than the propose FFL. So thoughts being to build brick/block up 30cm, install a DPC, fill in the floor with the required MOT, sand, DPM, insulation, slab then build off the wall from DPC.

So if the current slab is cracked in several places, I was thinking of laying some sort of shallow strip foundation for my floor retaining wall.

 

[^woody^]

Put a lintel across

 

[pilsbury]

interesting