Suspended floor underfloor heating

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Just wondering if anybody has experience with underfloor heating on suspended floor ? Are you happy with it and did you go for water system and how much did it cost.

We are having extension done in the summer and our floor is not insulated so when we get it insulated i'm looking at option of underfloor heating.
 
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I’m in the same boat and thinking about doing it mainly as a future proof in the event of us moving to a heat pump which seem to work much better with underfloor heating! I’d definitely go with a wet system as they just seem better!
 
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Does it have to be suspended flooring, can you not work in a solid concrete base? Reason I ask is that I had a cavity underfloor with electric mats, they worked great though the tiles all started coming loose or shattering due to flex in the floor. We ended up gutting the extension and starting again, new electrics, doors, windows, stone filled then concreted over with a new cosy toes heated element on the press in matting. It's fantastic and not costing us a fortune to run in the 5 months it's been in.
 
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I’m in the same boat and thinking about doing it mainly as a future proof in the event of us moving to a heat pump which seem to work much better with underfloor heating! I’d definitely go with a wet system as they just seem better!
Didn't know that it works better with heat pump. From my understanding we are all gonna have to change from gas in near future so you have helped me make up my mind and definitely go with wet system.
 
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Does it have to be suspended flooring, can you not work in a solid concrete base? Reason I ask is that I had a cavity underfloor with electric mats, they worked great though the tiles all started coming loose or shattering due to flex in the floor. We ended up gutting the extension and starting again, new electrics, doors, windows, stone filled then concreted over with a new cosy toes heated element on the press in matting. It's fantastic and not costing us a fortune to run in the 5 months it's been in.
New extension will be concrete but we will run the pipes into our current house which has suspended flooring. Might have to two areas as I'm sure system for suspended flooring is different to concrete one.
Can't wait as our floor has no insulation and during winter it's freezing to walk barefoot.
Do you only have underfloor heating or do you have some radiators as well ?
 
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New extension will be concrete but we will run the pipes into our current house which has suspended flooring. Might have to two areas as I'm sure system for suspended flooring is different to concrete one.
Can't wait as our floor has no insulation and during winter it's freezing to walk barefoot.
Do you only have underfloor heating or do you have some radiators as well ?
We still have our oil fired CH too so rads in every room, they are rarely on though as the floor is set at a constant 23-24degrees throughout the ground floor. It only really comes on to heat the water for washing.
 
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We still have our oil fired CH too so rads in every room, they are rarely on though as the floor is set at a constant 23-24degrees throughout the ground floor. It only really comes on to heat the water for washing.
I understand, makes sense. I'm thinking the same keeping all radiators upstairs and having a few downstairs where underfloor heating will be.
 
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Didn't know that it works better with heat pump.

the UFH doesn't work better with a heat pump, the heat pump works better with UFH as the heat pump gives out a lower temp water than a boiler.

i've recently fitted it in a suspended floor but untill i do the kitchen floor the manifold isn't connected to the boiler so can't comment on how well it works, eventually upstairs will be all rags and downstairs all UF.

my mate who's the plumber that fitted it has done his whole bungalow the same, suspended floor and boarded and carpeted on top and it works well, he just had to be carefull on the carpet and underlay so it didn't block the heat.
 
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the UFH doesn't work better with a heat pump, the heat pump works better with UFH as the heat pump gives out a lower temp water than a boiler.

i've recently fitted it in a suspended floor but untill i do the kitchen floor the manifold isn't connected to the boiler so can't comment on how well it works, eventually upstairs will be all rags and downstairs all UF.

my mate who's the plumber that fitted it has done his whole bungalow the same, suspended floor and boarded and carpeted on top and it works well, he just had to be carefull on the carpet and underlay so it didn't block the heat.
Thanks for that info ! Do you know which system you went for, where you bought it from ? I've seen so many places sell different systems for suspended flooring, not sure which is the best. Some use aluminium boards that pipe runs through to spread the heat better.
 
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I've got water based underfloor heating in our suspended floor extension.
It's pretty disappointing tbh but that could also be because we have a wood floor on top, 7m of bi-folds and ceiling follows roof pitch so just has a layer of kingspan for insulation.

Anyway, they battened between joists, kingspan on top, ran pipes then screed over top, subfloor, thin ply and then wooden floor.

There's obviously a lot of contributing factors to why I'm not overly impressed with it, likely not due to it being on a suspended floor.
 
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I was looking into it and I've decided not to bother.
The people I spoke to said there would be a fair amount of heat loss through the suspended floor even with the reflecting plates.

With my extension I'll be doing a mix of underfloor heating in the extension area where it'll be concrete and big fat radiators in the original building.
 
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I was looking into it and I've decided not to bother.
The people I spoke to said there would be a fair amount of heat loss through the suspended floor even with the reflecting plates.

With my extension I'll be doing a mix of underfloor heating in the extension area where it'll be concrete and big fat radiators in the original building.
For any subfloor heating to work, you need to have some sort of reflective layer beneath the heat source as otherwise you are heating 365 degrees when you only really need the top 180 degrees.
 
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For any subfloor heating to work, you need to have some sort of reflective layer beneath the heat source as otherwise you are heating 365 degrees when you only really need the top 180 degrees.

I know but the issue I was told was that even with the reflective layer in place you still lose a lost of heat through that.
Whereas with a concrete base the heat loss is a lot less
 
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I know but the issue I was told was that even with the reflective layer in place you still lose a lost of heat through that.
Whereas with a concrete base the heat loss is a lot less
To an extent yea, I have the concrete base now too.
 
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From reading above guess I will have to speak to our architect and see if he knows anything about it. Will also ask builder companies when we are getting our quotes if they have installed any. Seems to be hit and miss :confused:
 
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Thanks for that info ! Do you know which system you went for, where you bought it from ? I've seen so many places sell different systems for suspended flooring, not sure which is the best. Some use aluminium boards that pipe runs through to spread the heat better.

i just went with the cheapest way for me to do it wich was pipes laid over the insulation and then a biscuit screed(25/30mm 8 to 1 sand/cement) to cover them finishing level with the top of the joists. thats the way my mate i mentioned above did it and his works well.
think the important bit whatever wqay you do it is to be carefull what floor finishing you put over it, to much timber will reduce the heat so i'm putting enginered boards down straight onto the joists eventually(temporay ply and cheap carpet at the moment to make the room usable) so will only have 20mm of timber over the screed.
it will also work a bit differantly to a solid floor and heat up/cool down a lot quicker so you wouldn't leave it on permantly like you might do with a 75mm screed.


i tiled a load of floors on a job a couple of years ago, the extension was solid floor(liquid screesd and great to tile) but the existing building was joisted floors and they put wet UFH on all 3 floors, i tiled the dining room floor and the 2 bathrooms. with that they fitted some plastic castleated sheets and the pipes pushed in between the castles which was fitted ontop of the existing floorboards, not a way i would do it as the rest of the gaps in the sheets needed filling with self levelling and they where 20mm deep, think it was about £600 of self levelling just for the dining room and it took me a while to mix and pour it. apparently it works well though even where it has carpet over it and i know they do like a hot house.
 
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i just went with the cheapest way for me to do it wich was pipes laid over the insulation and then a biscuit screed(25/30mm 8 to 1 sand/cement) to cover them finishing level with the top of the joists. thats the way my mate i mentioned above did it and his works well.
think the important bit whatever wqay you do it is to be carefull what floor finishing you put over it, to much timber will reduce the heat so i'm putting enginered boards down straight onto the joists eventually(temporay ply and cheap carpet at the moment to make the room usable) so will only have 20mm of timber over the screed.
it will also work a bit differantly to a solid floor and heat up/cool down a lot quicker so you wouldn't leave it on permantly like you might do with a 75mm screed.


i tiled a load of floors on a job a couple of years ago, the extension was solid floor(liquid screesd and great to tile) but the existing building was joisted floors and they put wet UFH on all 3 floors, i tiled the dining room floor and the 2 bathrooms. with that they fitted some plastic castleated sheets and the pipes pushed in between the castles which was fitted ontop of the existing floorboards, not a way i would do it as the rest of the gaps in the sheets needed filling with self levelling and they where 20mm deep, think it was about £600 of self levelling just for the dining room and it took me a while to mix and pour it. apparently it works well though even where it has carpet over it and i know they do like a hot house.
Loads of good info there thank you !!! I was actually looking at going with engineered wood so that's really helpful. At least now when I talk to builders and architect I'll know a bit more about the process.
Thanks again:cool:
 
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Just reading up about rugs and underfloor heating, apparently only certain type of rugs can be used otherwise it can cause damage to the floor :eek: Learn something new every day :cry:
 
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