UFH - First Floor ideas...

[Mulberry View]

We're building a 200sqm Nudura house, around 135sqm gross ground floor, 230mm PIR over B&B floor. In-screed UFH with around 50mm of liquid screed is looking likely.

 

First floor is just a Master Bedroom, Master Ensuite and a second Bedroom with a small Ensuite, around 65sqm total. We like warm floors in the Bathrooms, so are thinking of going for Roth Clima Comfort mats with 10.5mm pipe over the 22mm Chipboard, their liquid screed over that as it'll make a nice substrate for the Microcement (that SWMBO simply will not compromise on). The Bathrooms are back-to-back and the Posi design is super-rigid.

 

Does anyone have experience of this type of system for first floor?

 

I gather we have to have some sort of emitter in the Bedrooms to qualify for the BUS grant? But we want nice carpets (not limited to 2.5tog), so the option I guess is UFH and just accept the performance loss (the heating will be minimal anyway) or fan coils, but we lose wall area with these I guess?

 

I realise the upstairs heating is debatable for most people, but I don't think we can go for no heating at all up there, I'd hate to have to do something retrospectively.

 

Also, what type of pipe? Roth have quoted for PE-RT (they have an Alu option but say it's overkill), Continal suggest PE-RT/AL/PE-RT....

[MPx]

The current project is an upside down house.  As things have progressed we have gone Passive and won't now have UFH.  However we too loved the UFH on our previous home under a stone floor (downstairs).  At the start of the design for the current I wanted to replicate that stone floor - but upstairs this time as that's where we will be living.  As such it is spec'd to have a Lewis Deck with 50mm screed (something like Kerracol) sat on top of the timber frame Chipboard finish.  The UHF would have sat happily in there if we'd decided to have some.  

 

Last place we had oversize Ali rads upstairs except in the bathrooms where I stuck to wet UFH.  Was a specialist "thin" polystyrene type of carrier with small diameter pipes - all from Wavin.  Make up - 18mm chipboard (wayrock) on the joists, Wavin poly/pipes, 12mm Plywood, Ditra Matting, Ceramic Tiles.   Worked very well for the decade or so we lived with it.

[Nickfromwales]

10 hours ago, Mulberry View said:

Does anyone have experience of this type of system for first floor?

I've installed wet UFH over FF P5 22mm decks many times, and screeded over them; from 'just enough' to ~50mm.

 

I used 16mm Pert AL, never use anything else, as laying UFH is somewhere OTT should be the standard....?  alarm bells are ringing.

[Nickfromwales]

4 hours ago, MPx said:

Make up - 18mm chipboard (wayrock) on the joists, Wavin poly/pipes, 12mm Plywood

Pipes routed into the P5? 18mm is a thin board to compromise.

[MPx]

No Nick.  The wayrock absolutely as standard.  Then the blue polystyrene panels with pipe channels (+pipes) laid on top.  Then the ply, ditra, and finshes. We put an oak "step" in the door thresholds to the en-suites but it was only 38mm and looked like we meant it more than it was a cover up.