UFH over flooring guidance

[vik2001]

im having a house refurb, a new concrete block and beam floor will mix with a old concrete floor in the house


can i do the following:
1. lay pir boards like cellotex floating 100m in the new extensions, and then 20mm in the old part of the house. this makes all the floor level one height throughout.
2. lay overylay ufh boards 22mm floating over the cellotex
3. then lay on top of the ufh boards a underlay, then engineered oak flooring (all floating)

would this work?

 

[Exedon]

Sounds like a overlay system and yes timber flooring can go strait on
Check if your proposed flooring is compatible by contacting underfloor manufacturer.

 

[vik2001]

Can the ufh overlay boards be placed directly over the kingspan/cellotax insulation boards?

 

[Madrab]

I wouldn't, use a 6mm cementitious board like no more ply on top of the kingspan, then the EPS overlay. The wood can sit happily on the overlay boards without underlay, or make it 2mm foam to minimise interrupting the thermal transfer

You'll need to use floor probes and keep the UFH limited to around 26Deg or a DEG or 2 below what the flooring manufacturers recommend.

 

[vik2001]

I wouldn't, use a 6mm cementitious board like no more ply on top of the kingspan, then the EPS overlay. The wood can sit happily on the overlay boards without underlay, or make it 2mm foam to minimise interrupting the thermal transfer

You'll need to use floor probes and keep the UFH limited to around 26Deg or a DEG or 2 below what the flooring manufacturers recommend.

Can the no more ply be left floating over the kingspan 100mm insulation? Or does it have to be glued down in anyway. Then the Eps overlay left floating?

 

[Madrab]

I have the EPS directly on P5 that is sitting on a concrete slab.

I don't think that there would be any issue with the cement board just sitting on the kingspan but you could just use a contact adhesive to 'glue' it down, then the same for the EPS to the boards.

The wood can then just float on top of the EPS.