Help UFH installation

[Nawaz Ahm]

Hi - some advice would be appreciated.

We are doing a refurb and are having water based underfloor heating installed.

The top layer will be 15mm engineered wood (floating).

Our builder has done things in a backward way so I need advice on what is the best solution given the circumstances.

Builder has installed 100mm of foil backed insulation and then 100mm of sand & cement screed. I have 2 options

1) He is proposing to staple 16mm pipes to the screed and pour 25mm of self leveling screed on top of the pipes.

2) install 20mm wundatherm insulation boards, 3mm breathable underlay & then the top layer.

Which is better solution and is 25mm enough for liquid screed.

Ripping up the existing screed is not an option unfortunately.

Any advice would be appreciated

 

[IND_Nick]

I would call up one of the UFH manufacturers or suppliers and discuss it with them, try Uheat . I'm pretty sure you can't staple pipes to screed and then self level over. It would need to be a retrospective type system. There's loads on the market, usually about 18mm thick with groves to accommodate 12mm pipes. Some are foams based for floating floors, we often fit a heavy duty/concrete based board and just liquid screed over it for a smooth finish. Definitely worth talking to some suppliers for option, don't forget thermostat locations, zoning and make sure the heating system is split if you have radiators in the rest of the house. We go to loads of 'builders' UFH systems that are done very poorly.

 

[Phill K]

Bar ripping the screed up and making him do it properly, only option left is over floor/underfloor as Ind said but then have you got the floor height to accommodate another 50mm of screed which pipes are supposed to be in for protection and to stop the screed cracking from the heat?

 

[king of pipes]

Only option is a overlay system Omnie do this one as below it's one of the lowest build up height systems available, be careful choosing you're engineered timber floor it's moisture level must not be higher than 8 - 10% and gently, gently with the first switch on

 

[Gnorw er’uoy]

JK floorheating | jk-gb.com

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Look at this as an option