I laid a 4x3 metre concrete base for my summerhouse/office thing. The corners are all level and so the summerhouse sits fine, but it dips in between and so the load bearing battens aren't taking any load.
I've been looking for solutions to this (without digging it all up) and as far as I can see, I can use self leveling cement stuff, or mortar.
The question is thus, as I don't need the entire floor to be perfectly flat as there is obviously going to be a wooden base added over the battens, can I use mortar or similar to just raise the floor under the battens to make then run level with the rest of the summer house. Or do I need to cover the entire base in self-levelling cement or similar to level the whole thing out?