When I had my extension built last year I had the builder lay the floor for a conservatory as well as it joined the new kitchen and dining room. Now I'm ready to have the conservatory done I'm wondering how to finish the floor to the correct height. I have 2 problems - 1st - somehow the builder got the levels wrong and the sub floor is 135mm lower than the finished floor of the house. When I did the new kitchen floor I laid 70mm Sellotex and then a screed of 55 mm. 2nd - I don't particularly want to go down the screeding road in the conservatory as I don't have the time or inclination to do it myself and if I want someone to do it for me I'll have to wait at least 8 wks. Can I lay a thicker Sellotex and then 22mm flooring chipboard with floor tiles or wood laminate flooring. Another idea is can I have a timber network say 100mm x 50mm and then chipboard with tiles or wood laminate? The sub floor is to building regs standard with the necessary damp proof membrane etc.