UFH on top of chipboard floor

[JamesV]

Hi everyone,

 

I'm looking at installing wet underfloor heating on top of a chipboard floor in a small bathroom of my 1920 renovation property (it's about 4m2).  It's going to be connected to an ASHP and we think we'll need the UFH to get enough heat into the bathroom in winter whilst keeping the ASHP temperatures low.

 

The bathroom is on the ground floor and the floor surface is a newly laid moisture-resistant 22mm chipboard glued and screwed on approx 350mm joist centres with no material deflection. Underneath we've got 200mm of rockwool so no material heat loss downwards.

 

We're trying to avoid a huge step up in the finished floor compared to the hallway so we are looking at using a castellated egg panel system with a screed (e.g. Profix Panels https://profixpanel.co.uk/introduction-profix-panel with Mapei 3240 Self Leveling compound). The finished floor surface will be tiled.

 

There doesn't seem to be a great deal of information around about doing - does anyone have any experience of doing something similar? Profix have said it's possible to use the system on chipboard but recommends using an acrylic dispersion primer before laying the panels. I haven't found one that says it's suitable for use on moisture-resistant chipboard and Profix don't recommend a specific product. I'm also a little concerned about tiles cracking in the long term if I don't get this right.

 

I've also looked at using overlay panels but these all seem to require overboarding the chipboard with plywood or cement boards before laying the panels and so the floor build-up becomes quite excessive.

 

Many thanks,

 

James

 

[LiamJones]

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