Overboarding wood and concrete floors

[oliver123]

Hi

I need to raise the floor of my kitchen so that it is the same height as the dining room floor. The kitchen floor is half floorboards and half concrete. Can I just overboard with ply on both of these surfaces or do I need to do something different on the concrete?
The height difference between the two rooms is roughly 18mm.

Thanks

Oliver.

 

[bookahandyman]

you could lay 18mm ply on the floorboards and mix a screed to fill other half but is messy and time consuming. you could just lay 18mm t&g P5 ( water resistant) Chipboard flooring on the concrete, but it may wobble a bit if its not 100%level. I would clean off concrete , Coat it with slightly diluted PA and let dry. then you can buy wood flooring adhesive and stick it down to the concrete. this can either be the messy complete cover adhesive or slighlty dearer silicone gun style tubes of adhesive which you lay strips approx 100-150mm aprat from each other and lay on the board. then carry on laying same T&G P5 chipboard across timber floor fix with screws every 150mm or so.some people put a vapour barrier on the concrete first but this takes away the gluable aspect of the job and you would have to mechanically fix it then. ( also putting holes in the vapour barrier.) if no evidence of moisture or damp then just stick it down.as long as concrete was insulated underneath.

 

[WoodYouLike]

If possible, stay away from chipboard - it will reduce your options in floorcoverings.
Use plywood instead

 

[mac391]

18 mm ply over the whole area.

Screw to original joists at the timber end. Lay a 1200 gauge visqueen to the concrete end and overlay with same 18mm ply. Hire a hilti nailer to fix the ply or plug and screw to concrete.

 

[oliver123]

Hi

I am now set to do this job but just one more question!

Treated chipboard is half the price of ply - what are the pro's and cons of each material?

I have checked and the concrete is laid on a waterproof membrane.

Thanks

 

[NicG2]

Treated chipboard means you cannot secret nail and I think you will struggle to find a glue that will bond with it, pretty much limits you to floating. This may not be a bad thing but without knowing what your end floor is like it's difficult to recommend it.

As WYL said, ply expands your options.