i've got a greenhouse for on my allotment and i'm building a single breezeblock course to sit it on. ive built small walls before but ive never done footings, can anyone tell me how deep they need to be and what mix would be best. its just a standard 8x6 aluminium greenhouse.
its quite firm clay. part of it is going to be where the compost heaps were till a week ago. its going to be 4 walls under the sides inside there will be 4 foot by 6 foot slabbed so i might build another wall so all the good compost doesnt disapear under the path