Raising floor by aprox 18mm

[tinno]

Hi, I have scratched my head over this problem many many times.

I have had somebody in to help, but now it doesn't seem sturdy enough and I want to start again. I want it to last!!!!

We have had an extension to the lounge. The "new" concrete floor is 18mm or there abouts, lower than the "old" timber floor. I therefore need to raise the new concrete floor so it is level with the old floor.

The guy that came round (very helpful) suggested 12mm ply on top of 6mm hardboard strips. He has partially laid it but it feels quite bouncy underfoot, which makes me think 12mm ply is not thick enough.

Has anybody got experience of this type of problem and what was the remedy. Thanks guys.

 

[foxhole]

18mm ply, or 18mm screed on top.

 

[tinno]

Thx foxhole - if I go:-

1) 18mm ply - do I just screw it to the concrete

2) 18mm SLC - can you use SLC up to a depth of 18mm without cracking?


N.B I've checked the level of the floor, one half of the concrete floor is 18mm out, the other half is 9mm out, obviously there is a gradual slope in the middle that trascends the 9mm - 18mm difference. The old wooden floor is straight as anything!!

So, which would be easier the 9-18mm ply screwed onto the concrete or SLC - which would give the better long term performance or they both equal?

 

[foxhole]

Ideally the ''new'' floor should have been laid at the correct depth and leveled, a further screed will be best solution if the current floor varies in depth.

 

[xr4x4]

Ideally the ''new'' floor should have been laid at the correct depth and leveled, a further screed will be best solution if the current floor varies in depth.

2nd

 

[Harbourwoodwork]

Hi, I have scratched my head over this problem many many times.

I have had somebody in to help, but now it doesn't seem sturdy enough and I want to start again. I want it to last!!!!

We have had an extension to the lounge. The "new" concrete floor is 18mm or there abouts, lower than the "old" timber floor. I therefore need to raise the new concrete floor so it is level with the old floor.

The guy that came round (very helpful) suggested 12mm ply on top of 6mm hardboard strips. He has partially laid it but it feels quite bouncy underfoot, which makes me think 12mm ply is not thick enough.

Has anybody got experience of this type of problem and what was the

remedy. Thanks guys.

try posting in the flooring section