New Stag House

[edd]

I used to use my brother's pit and leave the handbrake off and just roll it to where I wanted it, putting blocks either side of a wheel to hold it in place. The secret it getting the depth of the pit right, oh and he had large purpose made planks that stopped anyone falling in.

What do you mean by cavity wall not allowed on regs Edd?

A friend of mine tried to build in a cavity wall on his garage building regs didn't allow it. It's most likely because it's a back door route to a habitable space which in turn should adhere to another whole plethora of regulations.
I think either ensuring the floor slab is think enough for a future inner wall from thermalite is best and under the slab a nice 100 mm of celetex. Garage conversions are becoming really popular.