Will extend the wooden deck to place a hot tub there. Digging out and planning on using type macadam and then concrete slabs for the joists to rest on. Will screw the decking directly into the joists which are set 30cm apart. Living in Skåne and the ground is clay soil. Now to the question, how thick a layer of macadam or similar is needed, do you need to use bedding sand under the concrete slabs, and in what layers do you lay the geotextile fabric?
