B
Bill
Dry fix should cost more because you are having your 100mm of top up from the base added as the tiler fixes his tiles so you are saving on the concrete screed, the labour of the concrete screed and then the waiting time for the concrete screed to dry.
Personally, I think you are not explaining everything to us and you most certainly don't understand what different methods work.
Personally, I think you are not explaining everything to us and you most certainly don't understand what different methods work.