Will my UFH require its own zone valve?

[russ9898]

Hi,

New member here looking for a little advice in regards to a wet UFH system.

I am currently in the process of a refurbishment project to my soon to be new home renewing the central heating system throughout the property, I would like to add UFH to the bathroom but would like to know whether my proposed setup will work or whether in your expertise I am likely to need to reconfigure to avoid a poor performing heating system. A little information regarding my proposed heating system:

Boiler – Ideal Logic+ 35kw Combi Boiler
Zone Valve 1 – Downstairs Rads
Zone Valve 2 – Upstairs Rads (Inc UFH and towel radiator within the Bathroom)

The UFH will likely be the single zone kit linked below albeit with the included stat omitted/not used within my install and will instead rely on the programmer/smart stat controlling zone valve 2 to control the UFH and the upstairs rads as one.

10sqm-single-zone-water-kit - https://pswtradesuppliers.co.uk/single-room-water-kit/141-10sqm-single-zone-water-kit.html

I would be interested to hear your thoughts on the above as to whether the 2 zones will work or whether I am likely to require a third independent zone solely for the UFH system to be controlled by the thermostat included with the UFH kit.

Thank you in advance for your assistance,

Russ

 

[Murdoch]

What does your GSR recommend?

 

[russ9898]

What does your 'Registered Professional Gas Engineer' recommend?

I only intend to employ a Gas Safe engineer to install and commission the boiler and as such haven't consulted them for advise.

 

[ShaunCorbs]

Yes needs it’s own zone unless going electric matting wouldn’t go with the kit you’ve linked tho

 

[russ9898]

Yes needs it’s own zone unless going electric matting wouldn’t go with the kit you’ve linked tho

Can I ask why you wouldn't go with the kit linked? Are you able to suggest an alternative?

 

[Murdoch]

Brave man taking responsibility for the design

 

[russ9898]

Brave man taking responsibility for the design

Thank you for a further helpful post. The Gas Safe engineer will not be taking responsibility for the design of the system, simply doing final connections and commission.

 

[EvilDrPorkChop]

You won't be able to tap into the 'Zone 2' you'll need an additional zone that's independent of anything else with flow and return pipework from the boiler (Or wherever your zone valves are)

 

[ShaunCorbs]

One because it’s cheap unbranded gear so spare parts good luck

two it’s for a ground floor before the screed has been laid as it’s upstairs you would need an overboard system

 

[russ9898]

One because it’s cheap unbranded gear so spare parts good luck

two it’s for a ground floor before the screed has been laid as it’s upstairs you would need an overboard system

Thank you again for your response, I will look at sourcing an alternative system, are you able to suggest/recommend?

My plan is to lift to lift the existing floorboards to expose the floor joists and install pre grooved insulation boards (linked below) before renewing the bathroom floor with 22mm cement board therfore negating the requirement for an overboard system.

ProWarm™ Foiled Faced In Joist/Batten System

ProWarm™ Foiled Faced In Joist/Batten System available to buy online at The Underfloor Heating Store. Free delivery on all orders.

www.theunderfloorheatingstore.com

 

[ShaunCorbs]

The ones you’ve linked arnt a structural board so you would need to fill in the joist space with ply to span

over kit

https://wd906.infusionsoft.com/app/attachment/769/88ba284cfcf3ca537418bcafad1eeab8

Structural

Suspended floor underfloor heating systems | Joisted floor

We offer a full range of solutions to install suspended underfloor heating systems quickly and efficiently on timber, joist, or engineered joists.

www.ufh.co.uk

Wouldn’t recommend you overboard with cement board as it’s an extra layer if you want tiles infill with ply then use a cement overboard eg the kit above (overboard)

 

[russ9898]

Thank you, will have a thorough read of the links you provided over a cuppa on the morning.

Just to clarify, the pre-grooved insulation boards I linked previously woudnt be used as structural floor, they would be installed inbetween joists with the top face (where the UFH pipes are run) sitting level with the top of the joist which would allow the 22mm cement board to act as the structural floor with being laid ontop of and fixed into the joists whilst simultaneously sitting ontop of the UFH pipes and conducting heat through to the tiled floor.

 

[ShaunCorbs]

Just watch your max span with cement board last time I looked it was around 450-500mm max also this wouldn’t give good heat transference even with tile addy onto the ufh

 

[IND_Nick]

As above I would always recommend using branded/reputable products as they are generally more reliable and when it comes to spares they are a lot easier to source. Try Uheat the forum sponsor, we have used them for years and never had a problem.
Best practice would always be to have the UFH on a separate zone controlled by the thermostat in the room it heats. You can use the pre-groved insulation, as a preference I prefer insulation below and a metal spreader plate as I think it gives a more uniform heat delivery. I would also normally ply over and then use a thin tile board before tiled floor.
You will find the whole process quite costly for just one bathroom though.
Have you consider an electric UFH mat, especially as it is just a secondary heat source.
If you have a towel rail and really just want a warm floor when the heating is on, you could fit without a separate zone and just pipe stat etc. You would still have to incorporate the pump into the existing heating control setup though. It would work but wouldn't be ideal.

 

[russ9898]

Thank you both for the replies. (Trying to get multi quote to work but I'm being abit of a forum Noob I think.

Shaun - Thank you for your further advise. I have had a measure of joist spacings whilst at the property today and spacings are 400mm centres so not an issue in that regard however I do take on board your point regarding heat transfer however I did read (albeit on a manufacturers page) that cement board is good for wet UFH (Link below), that said I am going to look into IND_Nicks suggestion rather than my initial idea.

STS Construction Board TG4 18 & 22mm — STS

STS Construction Board TG4 is a unique A1 Fire Rated, Fibre Cement Floor board designed to be installed direct to joist, removing the need to overboard prior to finished floor surface. The heavy duty nature of this board enables it to be used in many construction applications both internally and ext

www.sts-uk.com

As above I would always recommend using branded/reputable products as they are generally more reliable and when it comes to spares they are a lot easier to source. Try Uheat the forum sponsor, we have used them for years and never had a problem.
Best practice would always be to have the UFH on a separate zone controlled by the thermostat in the room it heats. You can use the pre-groved insulation, as a preference I prefer insulation below and a metal spreader plate as I think it gives a more uniform heat delivery. I would also normally ply over and then use a thin tile board before tiled floor.
You will find the whole process quite costly for just one bathroom though.
Have you consider an electric UFH mat, especially as it is just a secondary heat source.
If you have a towel rail and really just want a warm floor when the heating is on, you could fit without a separate zone and just pipe stat etc. You would still have to incorporate the pump into the existing heating control setup though. It would work but wouldn't be ideal.

Thanks for your post Nick. I have just been having a look on Uheat and seen the following kit:

Adept AD-PLATE Timber Water Underfloor Heating Kits

Adept Timber Heating Kits are all designed for a single zone, however can be adjusted with the use of any Adept or Heatmiser controls from within our store.

www.uheat.co.uk

The kit linked above on the face of it seems to be perfectly suited to my needs however I am confused by the lack of pump and blender valve. It would appear the kit goes on the rad circuit and uses the radiator valve for temperature control? I'm presuming a more conventional setup with an independent pump, blender valve and zone valve would be more effective than the kit linked above?

I'm presuming when you state you would ply over you would use 18/22mm ply as a structural floor with say a 6mm tile backer board?

Thanks again for your help.

Russ

 

[Uheat – Jake]

Thank you both for the replies. (Trying to get multi quote to work but I'm being abit of a forum Noob I think.

Shaun - Thank you for your further advise. I have had a measure of joist spacings whilst at the property today and spacings are 400mm centres so not an issue in that regard however I do take on board your point regarding heat transfer however I did read (albeit on a manufacturers page) that cement board is good for wet UFH (Link below), that said I am going to look into IND_Nicks suggestion rather than my initial idea.

STS Construction Board TG4 18 & 22mm — STS

STS Construction Board TG4 is a unique A1 Fire Rated, Fibre Cement Floor board designed to be installed direct to joist, removing the need to overboard prior to finished floor surface. The heavy duty nature of this board enables it to be used in many construction applications both internally and ext

www.sts-uk.com

Thanks for your post Nick. I have just been having a look on Uheat and seen the following kit:

Adept AD-PLATE Timber Water Underfloor Heating Kits

Adept Timber Heating Kits are all designed for a single zone, however can be adjusted with the use of any Adept or Heatmiser controls from within our store.

www.uheat.co.uk

The kit linked above on the face of it seems to be perfectly suited to my needs however I am confused by the lack of pump and blender valve. It would appear the kit goes on the rad circuit and uses the radiator valve for temperature control? I'm presuming a more conventional setup with an independent pump, blender valve and zone valve would be more effective than the kit linked above?

I'm presuming when you state you would ply over you would use 18/22mm ply as a structural floor with say a 6mm tile backer board?

Thanks again for your help.

Russ

Hi Russ,

Feel free to give us a call and we can provide a price for your requirement with a mixing valve and pump.

Regards,
Jake

 

[russ9898]

Hi Russ,

Feel free to give us a call and we can provide a price for your requirement with a mixing valve and pump.

Regards,
Jake

Thanks Jake. I am working in quite a remote location for the foreseable with limited phone reception during office hours however I have completed a quote request on your website this morning with some additional information which will hopefully provide adequate information to price.

 

[IND_Nick]

Thank you both for the replies. (Trying to get multi quote to work but I'm being abit of a forum Noob I think.

Shaun - Thank you for your further advise. I have had a measure of joist spacings whilst at the property today and spacings are 400mm centres so not an issue in that regard however I do take on board your point regarding heat transfer however I did read (albeit on a manufacturers page) that cement board is good for wet UFH (Link below), that said I am going to look into IND_Nicks suggestion rather than my initial idea.

STS Construction Board TG4 18 & 22mm — STS

STS Construction Board TG4 is a unique A1 Fire Rated, Fibre Cement Floor board designed to be installed direct to joist, removing the need to overboard prior to finished floor surface. The heavy duty nature of this board enables it to be used in many construction applications both internally and ext

www.sts-uk.com

Thanks for your post Nick. I have just been having a look on Uheat and seen the following kit:

Adept AD-PLATE Timber Water Underfloor Heating Kits

Adept Timber Heating Kits are all designed for a single zone, however can be adjusted with the use of any Adept or Heatmiser controls from within our store.

www.uheat.co.uk

The kit linked above on the face of it seems to be perfectly suited to my needs however I am confused by the lack of pump and blender valve. It would appear the kit goes on the rad circuit and uses the radiator valve for temperature control? I'm presuming a more conventional setup with an independent pump, blender valve and zone valve would be more effective than the kit linked above?

I'm presuming when you state you would ply over you would use 18/22mm ply as a structural floor with say a 6mm tile backer board?

Thanks again for your help.

Russ

Morning,
Yeah we use 18mm ply as a structural base, then layer of whatever else before flooring. We do a lot of LVT so normally a cross layer of 12mm ply screwed and glued. Or tile backer boards if required.

 

[russ9898]

Hello all,

Just a quick follow up to the thread. As suggested by IND_Nick, I contacted Uheat to spec a system and provide quote which I am please to say has now been paid for and awaiting delivery. Thank you to all of you for your input and taking the time to reply.

Russ