Help oak flooring dilemma

[Ellasdad5]

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 said it was a solid floor that it was under the laminate, not 70mm below!
So, how do I fit my flooring now? I clearly need to keep insulation but I have issues with the height of the floor, it's already too high by a few mm at the french doors due to dodgy installation.
Would 50mm insulation between 50mm battens and 12mm ply be o.k to secret nail to? This would give me the right height but I'm conscious its an expensive fix. I have been told the boards need to be fixed to at least 3 battens which is going to prove impossible with many of them being 40, 50 or 70 long, hence the need for ply. Any ideas...I'm no pro as you prob'ly guessed!

 

[owenhynes]

When plying like you are on top of battens you have to use at least 18mm ply, unless of course you are going to definately use 18mm boards

 

[Ellasdad5]

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 say yes someone If this is the case, I'll batten to the concrete with insulation between and secret nail straight on top?

 

[owenhynes]

its a little unusual to be battening then nailing onto a concrete sub-floor, but before i go further into things whats the difference between your sub-floor now and your ideal finshed height (including your oak boards)
Owen

 

[mointainwalker]

various lengths from 40mm to 1200.

You don't seriously mean 40 mm , do you ?

 

[Ellasdad5]

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 chipboard. Reducing the insulating boards to 50mm (and 50mm battens) with the 18mm oak boards will do fine I think, just have to make sure the battens are not too far apart.

 

[owenhynes]

have you actually got results for these 'tests'? i would love to see them, compared to fully stuck down method in england theres really no camparison tbh, if you would really like to plug and screw all them batterns to the concrete floor then go ahead but, it would be much easier and quciker to even lay a thick screed lets say 40mm if that would do you? then including your dpm etc along with a 3mm top screed, then fully bond to that, okay it may cost you more but its a lot better and preferred method for a lot of fitters.

 

[Ellasdad5]

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.