Can flooring be laid straight onto concrete slab?

[subzero]

We've had to replace all the floors in our house, as part of a renovation. They have been constructed using 100mm insulation and there is UFH laid within new concrete slabs. However, there is no top screed, just the concrete slab itself on which to lay the final flooring. My concern is that the concrete has started to wear in one or two 'high footfall' places, while work continues on the house.

We are planning on laying wood flooring throughout (a decent laminate, rather than engineering oak etc). Will we have to lay a smooth finish to the entire slab before we can lay the flooring?
Or just apply some levelling compound in the areas where the concrete has worn?

Thanks for any advice

 

[Notch7]

It would normal to lay a concrete oversite, then the insulation, then underfloor heating, then screed.

Are you saying you dont have the screed? -concrete oversite isnt usually very flat at all.

 

[subzero]

Correct, no screed.

 

[Notch7]

Correct, no screed.

Was there a reason for doing that? -when the floor slab was done, I guess somebody set out levels, so there should be a datum showing the finished floor level.

I wonder what level the concrete oversite was set to?

My guess is you need to use self levelling compound to create a flat and level surface, but what thickness that is will depend on what your datum point is.

 

[subzero]

The original floors were in a poor state, and we were advised to replace them to modern specs with insulation etc, and since a new heating system was required, the opportunity was taken to install UFH at the same time. The job was done in two stages, and by two different tradesmen. The level was actually set, during the first stage, to the level of the original skirting. Not ideal, but that's where we are.

My only thought is, would it be better to tile the entire ground floor, with adhesive straight onto the slab? Rather than levelling, then underlay, then final flooring.. although the UFH gives out a nice heat, I do wonder how that will be degraded by two layers of such flooring.

I just realised I've probably posted this in the wrong section since it's a topic about flooring rather than building per se.

 

[Notch7]

with adhesive straight onto the slab? Rather than levelling

I would be surprised if concrete would be flat enough -you need to know what the variation in height is first before deciding what to do.

Maybe the slab was floated and is pretty level, I dont know if thats possible or probable really.