Just to update... got the timber planed to 65mm the same as the insulation and fitted the battens at 30cm spaces. Then cut the celotex to fit between and used tonguetite screws to fasten the floor. Result is a perfect, solid great looking floor...with the insulation retained.
All the web research I've done says battens are a well tested method of fixing oak flooring to concrete, I can't consider glueing the floor direct to the concrete as I need some insulation underneath it plus it would be far too much of a drop into the room. The current floor is 65mm plus 18mm...
Hey, thanks for the quick reply! I guessed you would say the ply needed to be thicker. I'm now thinking the advice to nail to 3 battens was a bit o.t.t. If the battens are no more than 30cm apart (all t&G) surely a solid result can be achieved by mixing the different lengths properly?
Please...
Howdy, here's the prob. Just moved house and bought a load of solid oak flooring 18mmx120 various lengths from 40mm to 1200. Having ripped up the old laminate I've found underneath is 'orrible chipboard which is floating on 65mm cellotex which sits on concrete. I assumed when the previous owner...