Was at a new build job the other day doing the fluffy stuff throughout and there was another firm doing the spacia. about 50ish m2 in total kitchen, dining, utility, 3 bathrooms The lads belted down 131 then 700 throughout on the new chipboard Now its not what i would do, so asked em what they were upto, got 'this is what we always do nowadays' Fair nuff i says calls f ball tech 'Nope, not advisable, we say ply' figured they would lol Was chatting to the amtico rep about something else later and asked his impression 'upto them, but we wouldnt warranty it if it wasnt done to BS' Opinions?
If the manufacturer says no, that's good enough for me. Another issue is no matter how well you can screed it will never be as flat as ply over chipboard. Do you ever think if you did this and it went wrong how you would explain yourself to the customer?
small areas you can get away with it. Larger areas the joints of the chipboard will show as you actually cause the joints to flare through the dried screed. (looks like 2' wide cupped floorboards in the sun light) Also a lot of these floors may blow in the future as the waxes in the plywood stop it bonding. But they may be lucky as its fibre-reinforced and will just sit there.
