Raising an existing concrete floor that's lower than rest of house All manner of questions and solutions to problems and issues surrounding the subject of brickwork, blockwork and stonework

[Mistyderek]

I am renovating a house . There is an extension which has a 3m by 4m floor approx 200 mm lower than the rest of the house. It is a concrete slab topped with 25 mm of polystyrene and chipboard.

I am thinking about how to raise it 200 mm reasonably efficiently...Possible options [1] celotex then screed [2] two layers of celotex then chipboard and [3] 100mm kingspan then aircrete blocks laid flat with sand /cement brushed into joins..sort of like block and beam...what do people think?

[stoneyboy]

Hi Mistyderek,
Suspect it will come down to cost and convenience. I would choose 180mm expanded polystyrene topped with 22mm t&g chipboard sheets.
Regards S

[Mistyderek]

Yep, I think so as long as the BCO will live with it.

[stoneyboy]

Hi mistyderek.
You may have to incorporate a DPM if there is not one.
Regards S.