To screed or not to screed .. that is the question

[RonBowater]

My daughter is having a new extension built and her architect is recommending chipboard or engineered wood directly on top of 100mm insulation laid on top of the floor slab. She wants hot water under floor heating and the architect says that it is possible to get insulation pre-rebated for the UFCH piping so that it lives within the 100mm PIR insulation PIR band and effectively goes directly underneath the floor boarding.

I havn't seen a design like this before, being accustomed to a conventional screed (65-75mm) on top of the insulation with the UFCH piping embedded within the screed.

Although the architect's approach is maybe simpler and avoids one wet trade, I would be worried that the floor would be 'squeaky' and maybe feels 'bouncy' as the insulation compresses slightly and rubs between boards as people walk over the floor. The other downside of a screed I guess is that the UFCH needs to warm up the screed so that a room takes longer to warm up.


Any comments anyone please ?

Ron B.

 

[noseall]

Chipboard!

Wouldn't even burn it.

I personally like the idea of a concrete screed beneath my feet.

 

[Blagard]

I would be worried that the floor would be 'squeaky' and maybe feels 'bouncy' as the insulation compresses slightly and rubs between boards as people walk over the floor.

Any comments anyone please ?

Ron B.

Ron I would not be concerned aboout the Squeaky bit as I doubt that with the overboarding there would be that much localised compression.

Nice to hear of new systems and like you I know nothing about the proposed solution. I would be inclined to ask for a reference of where this system has been used before so that it can be visited. I wouldn't use it myself unless it has been proven in use as problem free. I'm OK with new systems when application of common sense can see it is "safe" but this one does make me wonder what might be a problem.

One thing comes to mind are tolerances. If the floor slab is a little uneven the weight of the system is not going to pin the entire foor down to it and your bouncy bits may happen just because the insulation is bridging the low spots. - Nope would not touch it! - Real world builders rarely get a floor perfect even when screeded.

Get the architect to submit the system specification to see what that says about the the surface it is applied to and the tolerances applicable - still would be uncomfortable about it though even with the boarding fixed through the insulation into the slab!

 

[Chukka63]

i dont have a problem with a chipboard floating floor myself,maybe im just younger than noseall .ive never used brown chipboard and wouldnt.yes you can get insulation with channels in for under floor heating.
i feel with chipboard you dont have to heat cold screed before you get the benefits

 

[Blagard]

yes you can get insulation with channels in for under floor heating.

Preformed insulation for the pipes, definately a well used product - but I have never heard of it with chipboard directly on top, only with a screed.