Or just to confuse things, you could build your brick wall on a 4" concrete foundations. Then add a couple more lines of concrete foundations within the walls and use sleepers on edge (with damp proof course between them and the concrete) to support the shed. New sleepers are typically 2.4m long and two of them should do the job on a normal sized shed as the perimeter will be supported by the wall.
yeah boosting it up with a wooden base was an idea i had, but i kind of wanted the challenge of building a wall! cheers for the tips. it's all going into the garden design ideas book.
Or just to confuse things, you could build your brick wall on a 4" concrete foundations. Then add a couple more lines of concrete foundations within the walls and use sleepers on edge (with damp proof course between them and the concrete) to support the shed. New sleepers are typically 2.4m long and two of them should do the job on a normal sized shed as the perimeter will be supported by the wall.
Have fun!