Underfloor heating for kitchen and hallway with tiled floor

zed4

Member
Hi,

We're about to have a new kitchen fitted next week. We're also having new tiles fitted to the floor in the kitchen and hallway. The hallway is already cold, so I'm wondering about adding underfloor heating.

The house has concrete floors downstairs, currently carpet in the hallway and laminate in the kitchen.

We'll be moving a radiator in the kitchen to fit the new kitchen units. So what's involved in fitting underfloor heating? Is it worth putting in whilst we're redoing everything? What do I need to know? Quick crash course please as I need to get bits ordered ASAP!!

The hallway is 1.2m x 4m and the kitchen has a floor area of around 3.2m x 2.2m (not including the kitchen units). Happy to have it all as one room/zone.

Many thanks,

Dan
 

zed4

Member
Well I was thinking of a wet system to replace the radiator which needed to be moved, I have a space cupboard I could fit a pump and manifold into, but I think the installation would be too thick to lay onto the existing concrete floors. In which case, do I need to go electric?
 

stiv674

Well-known Member
You can hire a special cutting tool to cut chases in to an existing concrete floor, I don't know the technical aspects of it but it may be a solution in your case.
 

IronGiant

Moderator
I think you generally have a different temperature for the water for underfloor. So it's not just as simple as replacing a radiator with pipe work. Not super complicated, but you need some sort of thermostatic mixer valve I think. e.g radiator water at 80deg C and underfloor at 45-50.
 

stiv674

Well-known Member
I think you generally have a different temperature for the water for underfloor. So it's not just as simple as replacing a radiator with pipe work. Not super complicated, but you need some sort of thermostatic mixer valve I think. e.g radiator water at 80deg C and underfloor at 45-50.
The underfloor manifold will deal with that.
 

zed4

Member
So thinking of going with electric then, as I'm not really able to rip up the floors.

Looking at the Prowarm kit, with a Heatmiser Electric Floor Heating Smart Thermostat Kit - Heatmiser neoKit-e
 

stiv674

Well-known Member
Not sure I'd go for electric underfloor as the primary source of heating, especially as you have a wet system available.
 

Wahreo

Distinguished Member
it mainly depends on the type of screed you have. If it’s a typical sand/cement screed then it’s a case of priming the screed, gluing foam insulation boards down, priming and then UFH then latex, priming and then tiles fixed
 

IronGiant

Moderator
I'm guessing dan cannot "afford" to raise the floor that much.
 

ufo550

Well-known Member
Unless you've got wads of cash, electric UFH will cost you. Wet UFH has a lower running cost, but in your situ higher installation cost. One of my last customers, we installed electric in his 1st floor ensuite & bathroom, I'd just turned on the shower for an extra minute myself.

His next project was jack hammering up the ground floor to install wet UFH.
 
When we did ours with a kitchen change we simply had the exiting radiator pipes capped or whatever the term is.

Then had the electric mats installed with tiling on top and heatmiser controls.

Very cost effective and plenty warm for the kitchen and utility rooms.
 
Last edited:

zed4

Member
We're going to relocate a radiator onto another wall, so the underfloor heating will be to take the chill off the tiles.

So how much thickness is required for electric UFH? How thick is the insulation and matting etc?

My builder is starting to rip out the kitchen today, so if I go with UFH, I need to order it today. I will have a word with him to see his thoughts.
 

zed4

Member
Unless you've got wads of cash, electric UFH will cost you. Wet UFH has a lower running cost, but in your situ higher installation cost. One of my last customers, we installed electric in his 1st floor ensuite & bathroom, I'd just turned on the shower for an extra minute myself.

His next project was jack hammering up the ground floor to install wet UFH.
Hmm, ok. The size I'm looking at is 1350 watts, which equates to around £0.19 to £0.20 per hour I believe. 3 hours a day is around £17.61 per month as I understand it. I guess I can live with that through winter.
 

Wahreo

Distinguished Member
I would seek the advise of a professional. Usually a Tiler would know the best way to construct the floor for UFH.

It definitely needs XPS board glued to the floor with tile adhesive. Then your wire/matting which must be tested before, during and after installation. Then the whole lot needs self levelling compound on top and then you can tile. Just for the Insulation, matting and compound, it’ll add a good 15mm or so, depending on how level the floor is. Then add the thickness of your tiles and adhesive on top of that.
 
Dan I installed Prowarm in my bathroom just before Christmas - If you floors are cold then I would highly recommend it.

I ordered 6m2 200w mat and 3iE thermostat for about £320. However I also installed the insulation backer boards so as much heat as possible goes up the way rather than being lost in the sub floor.

The mat is easy to use although it does restrict you on how you can lay out the floor a little bit. Prowarm also do a free cable option so you can choose a shape and route yourself that best suits your setup.

You cannot have the electrical cable under any units (as far as I understand it) as this can cause a build up of heat at that point and cause the mat/cable to fail.

As for the height difference I would so with the backer boards, mat, screed, tile adhesive and tiles the difference between my hall floor and bathroom floor is about 12-15mm which is a significant difference to be fair. However I would say the benefits the heated floor has on your tootsies, in my opinion is worth it.
 

Synchro

Distinguished Member
We got wet UFH in our new extension. Kitchen, living area & utility. Tiled on top, with stone slabs. We did not want the extra cost of lowering the floor in the existing house (dining room and hall), to take it right they way through, even though the same stone slabs have been used there. A thermal expansion gap is left between the heated and non-heated slabs, about half an inch, which is filled with a soft compressible material. It looks like a normal junction between rooms, which they will probably do even between UF heated and UF heated rooms, to avoid any jams.

I wish we had pushed the budget a little more as the wet UFH is by the best bit about the extension. Everyone, says how nice it is and believe me it is horrible stepping off the heated onto the non heated slabs when just wearing socks or bear feet. I know a few people who were getting extensions done after us and I convinced them to get it done. Eveyone says they love it. It is the way houses should be heated. Much more efficient and pleasant to be in a room that is heated below.
 

Synchro

Distinguished Member
Oh, and if you have a cat or a dog.......they will love you. We have pretty much acquired a neighbours cat since its been installed.
 

ufo550

Well-known Member
Its funny about peoples perceptions. I've installed just a few electric UFH, never been reliant on the tiler; he don't give a hoop, just splashes his glue & tiles about, regardless of the sensitive electrics below. Frankly, how that stuff survives its installation process, must be up in the lap of the God's.

Electric UFH is only a consideration in small areas, so when you step out of the shower or bath onto a tiled floor, you don't notice the difference in floor temperature. I'd just have a bath mat. Electric is hideously expensive to run, if thats not an issue, then jobs a gooden. Anything bigger, and your just poring money down the drain.

Where I work now, it is solely wet UFH & air handling. Very few like it. But hey hoe, I know of a few people that have installed it domestically, and swear by it.
 

stiv674

Well-known Member
Its funny about peoples perceptions. I've installed just a few electric UFH, never been reliant on the tiler; he don't give a hoop, just splashes his glue & tiles about, regardless of the sensitive electrics below. Frankly, how that stuff survives its installation process, must be up in the lap of the God's.
Agree with that, I've yet to meet a tiler that is happy to get involved with any electric underfloor system. I've always had to install the insulation board and heat mat.
 

IronGiant

Moderator
Thanks for the reality check. I was intending to install Italian Marble tiles in the bathrom that would increase the floor height by 1cm. Extending it another 15mm with electric underfloor heating just won't work :(
 

Wahreo

Distinguished Member
I’m pretty open minded about what type of UFH people should go for- you usually weigh up the pros and cons of each system and make a decision. Actually wet UFH would rarely even be considered in a small kitchen or the vast majority of bathrooms.

I stand by my statement that a Tiler should be doing the prep work. He is best placed to deal with working with the board, mixing up the adhesive, levelling the floor by pinging a laser line around points in the room, latexing to those markers. A Tiler should never be in a position where he has to tile directly on to the bare wire. That’s a bodge/DIY job.

If a Tiler is unable to do these things then perhaps he’s not a modern day Tiler as you need to do these things nowadays to provide a flawless finish. Tiling has evolved in recent years.

Don’t be too put off by some of the fixed views that wet UFH is the way to go- by all means do a quick comparison though.

I actually tend to push customers away from any type of UFH by suggesting LVT instead :D
 

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