Jablite

Jablite is a trade name, and the same product is available from Celotex, Kingspan an Styrofoam. (try adding .co.uk for their websites)

I would not make a floating floor as proposed as there is little weight to secure it. Screw some battens to the floor, add insulation and then fix proper T&G chipboard or softwood floorboards to the battens.

An 8 x 4 sheet is between =A360 and =A380 - without the ply backing

dg

Thanks for that.

I'm not sure I explained it correctly. I need (something) to bring the height of the concreted area up to the height of the adjoining suspended wood floor. That's adding 40mm to the concreted area.

Then I'm putting a floating floor across the whole lot. The new flooring will be laid like a laminate floor (except it's composed of solid wood planks).

The bit I'm unsure about is the (something) to go on top of the concreted area (and below the new wood planks),

THATS WAY TOO MUCH TO PAY.

Jaberlite is polystyerine, kingspane / celotex have twice the insulation value, getting a small number of 40mm sheets may take some doing, the odd sizes are normally only sold in packs.

Rick

Standard jablite is just expanded polystyrene sheets. You can expect to pay 8 to 10 quid a sheet for the 50mm thick panels at a builders merchant (I have not bought thinner sheets - but expect they would cost proportionately less). It is more usually set in a floor and then screeded over.

PIR foam (celotex et al) gives better insulation and is also denser and hence may be better in this application. A 25mm thick sheet ought to cost no more than 8 quid if you shop around. You could then top that with 12.5mm WBP shuttering ply to give you close to your finished level. (you may need a sheet of hardboard in there to get the exact match in level)

This is roughly how the ground floor of a pal's 20 year old house is constructed. Concrete base then about 40mm polystyrene then chipboard flooring. Dunno if the polystyrene is of a special type or grade, though.

Many thanks for that.