My proposed patio will be made with 450mm slabs. As it is at the back of the
house there will be no vehicles driving on it.

I have lots of sand and it is my intention to lay the slabs on a 100mm bed
of sand which has been dry mixed with a 1:15 cement addition.

Has anyone experience of this method? I appreciate that it is usual to put a
subbase of stone down first but that'll be around £300 extra and I've plenty
of sand.

mark