Making up a 15mm level difference

[garyo]

Hi,

I'm re-flooring a porch that's around 6 square metres. The sub floor is concrete, with two-thirds of it stepped down 15mm lower than the other third. I need to even out this difference before then laying 12mm plywood over the top of the whole floor to take an Amtico click finish.

The stepped-down part of the floor is also uninsulated, so a bonus would be to get something like 15mm cellotex in there, but I'm not sure if it's worth the bother of having to batten it for such a small benefit.

My questions are:
- Would I need to batten 15mm cellotex under 12mm ply? (if I could get hold of any that thin!)
- Are there any other products that I could use in my situation? I could potentially just fill it with 18mm ply and then make up the difference with some 3mm underlay or even self-levelling compound.

Thanks

 

[Ian H]

What about some 10mm and 6mm XPS boards? They have a very high compresive strength.

Or you could knock 10mm down into tile adhesive to get your 15mm.

 

[garyo]

Thanks Ian, that looks like good stuff. Should do the trick.