Wooden floor over celotex, with battens or without???

[jonnypron]

I know this sounds familiar, but have read the posts and find the info I need, so any advice appreciated.

So from top to bottom I was thinking (for garden studio);

- 225mm x 38mm wooden floor boards
- (maybe VCL or foil tape joins in celotex sheets)
- celotex
- concrete floor

Will the floor boards be ok directly on the celotex or should I use some sort of treated battens (100mm x 19mm) glued to the celotex to fix the floor boards to, or will this just compress the battens into the celotex too much? I guess you could use OSB T&G over whole floor?

Also not sure about VCL above celotex?

Thanks

 

[motorbiking]

For my garden room i cut the celotex in half long ways and run a beam inbetween giving 600mm approx spacing.

 

[jonnypron]

For my garden room i cut the celotex in half long ways and run a beam inbetween giving 600mm approx spacing.

I would do that but with a concrete base, I was advised not to lay timber directly on it as this is likely to rot, even if treated if any moisture gets in there or from the base itself.

 

[motorbiking]

Is there no DPC in the concrete? you could lay one.

 

[Deleted member 174758]

We normally install the VCL above the concrete, but below the insulation. Are your planks T&G? In general I'd expect to overclad the insulation with plywood then secret nail into that for planked flooring if there were no joists

 

[jonnypron]

We normally install the VCL above the concrete, but below the insulation. Are your planks T&G? In general I'd expect to overclad the insulation with plywood then secret nail into that for planked flooring if there were no joists

I suspect as you mention, the best bet would be to lay some 8 x 4' subfloor like OSB or Ply, then the flooring, which will be sanded scaffold boards as the main flooring. There's DPM in the concrete, but may well do the VCL underneath the celotex too.

 

[jonnypron]

Is there no DPC in the concrete? you could lay one.

There is a DPM under the concrete. Was under the impression that's more to aid the drying of the concrete.

 

[motorbiking]

Don't really understand how your concrete will get damp then? DPM is there to keep damp out.