Thread: raising floor level

Best guess FWIW: lay another layer of chipboard over the other and even the lot up with Ardit.

That said, the butt join may be a problem. Do an expansion joint with polyurethane sealant perhaps.

You can tile on concrete if it's in good nick; may need to seal it first though so the adhesive gets a good bond.

hi damo

i had a similar problem i removed a wall to create my new kitchen and was left with a 9m2 concrete slab from the old laundry ,

is it possible to get under the house and see if the slab is suspended or how thick it might be . if you are only talking 16mm it might be a lot easy in the long run to get hire a concrete planer and remove 16mm from the top of the slab .

i ended up removing the hole slab and laying new floor bearer ,joists and boards a very long job .
best of luck
rob

It Jags suggestion of removing the slab is unpractical you would be best putting tile underlay across the lot - Bridge the join with the underlay and using battens over the yellow tongue to level it.

Otherwise you will get a crack across the horizon at the edge of the slab.

Aren't we sposed to have expansion joints now anyway in tiled floors? Every x metres or somesuch.

Battens won't support underlay adequately.
I'd put a layer of 16mm waterproof construction ply over the yellow tongue and then sheet over all of the concrete and timber sections with 6mm cement sheet. With no cement sheet joins in the proximity of the concrete/timber join.

Originally Posted by echnidna

Battens won't support underlay adequately.
I'd put a layer of 16mm waterproof construction ply over the yellow tongue and then sheet over all of the concrete and timber sections with 6mm cement sheet. With no cement sheet joins in the proximity of the concrete/timber join.

I would add to this that if one sheet will cover your floor, and you're worried about subfloor/'part of the subfloor' movement, then use a semifloating thicker sheet of (I assume Bob) compressed cement sheet, instead of the 6mm.