Any underfloor heating advice would be great!
Discussion
Hi folks,
Can anyone advise me on a pending underfloor install in my own home, it is slowly driving me mad!
Just to set the scene, I'm a heating engineer to trade but have zero experience in underfloor heating, we are adding an extension onto to our house to create an open plan living area and have no Intensions of using radiators.
the underfloor will be installed onto a floating floor, I have been in touch with John guest and priced up their underfit board system which was all ok until they tell me that it can't be run in a counter flow pattern, which is what I was hoping to do, due to the layout in the board.
So.... I then got looking into the serpentine vs counter flow layout.I prefer the sound of the counter flow due to the even heat distribution over the serpentine but now second guessing myself and wondering if I'm splitting hairs between the two.
I then began to think of fitting insulation, kingspan or similar, between the joists and then installing the aluminium plate set up instead of using the John guest Underfit boards. Cost does come into eventually but I obviously can't afford to get this wrong.
If anyone has any input or experience in underfloor I''d really appreciate the advice. Locally nobody I know within the trade has installed any. Unfortunate that.....
To sum up my long and very boring thread. Serpentine or counter flow, Does it really matter? John guest underfit or insulation & aluminium plate install?
And just to add.... Can I whack down engineered wood directly on top of the underfloor pipework or is it safer to relay the existing floorboards then cheeky nail the engineered stuff?
God my Friday nights have changed!
Thanks for reading folks.... You may just save me from the local nuthouse!
Martin.
Can anyone advise me on a pending underfloor install in my own home, it is slowly driving me mad!
Just to set the scene, I'm a heating engineer to trade but have zero experience in underfloor heating, we are adding an extension onto to our house to create an open plan living area and have no Intensions of using radiators.
the underfloor will be installed onto a floating floor, I have been in touch with John guest and priced up their underfit board system which was all ok until they tell me that it can't be run in a counter flow pattern, which is what I was hoping to do, due to the layout in the board.
So.... I then got looking into the serpentine vs counter flow layout.I prefer the sound of the counter flow due to the even heat distribution over the serpentine but now second guessing myself and wondering if I'm splitting hairs between the two.
I then began to think of fitting insulation, kingspan or similar, between the joists and then installing the aluminium plate set up instead of using the John guest Underfit boards. Cost does come into eventually but I obviously can't afford to get this wrong.
If anyone has any input or experience in underfloor I''d really appreciate the advice. Locally nobody I know within the trade has installed any. Unfortunate that.....
To sum up my long and very boring thread. Serpentine or counter flow, Does it really matter? John guest underfit or insulation & aluminium plate install?
And just to add.... Can I whack down engineered wood directly on top of the underfloor pipework or is it safer to relay the existing floorboards then cheeky nail the engineered stuff?
God my Friday nights have changed!
Thanks for reading folks.... You may just save me from the local nuthouse!
Martin.
I installed this in my conservatory:
http://www.thefloorheatingwarehouse.co.uk/acatalog...
It's like the JG stuff and runs in a serpentine. I don't have an issue with the configuration as once it's been on for 10 minutes or less you wouldn't know which side of the room the inlet is at (room is 5m x 4m). It will never match the heat retention and feel of a proper screeded floor with wet UFH. I have laminate laid on top and as you'd expect it cools off quickly but that could be a lot to do with it being in a conservatory and the type of laminate. Also you can easily tell that the pipes are at 200mm centres when you walk across it. Don't get me wrong, it does the job as best as it can I suppose but it'll never match a proper wet UFH install with screeded floor.
http://www.thefloorheatingwarehouse.co.uk/acatalog...
It's like the JG stuff and runs in a serpentine. I don't have an issue with the configuration as once it's been on for 10 minutes or less you wouldn't know which side of the room the inlet is at (room is 5m x 4m). It will never match the heat retention and feel of a proper screeded floor with wet UFH. I have laminate laid on top and as you'd expect it cools off quickly but that could be a lot to do with it being in a conservatory and the type of laminate. Also you can easily tell that the pipes are at 200mm centres when you walk across it. Don't get me wrong, it does the job as best as it can I suppose but it'll never match a proper wet UFH install with screeded floor.
For our first bathroom, I went with the below insulation. It has the insulation and metal foil built in. The pipes then route through it. You get nigh on 100% of the heat up through the floor and simplier insulation between the joists..
It works well in our bathroom, but does take an hour for the heat to start passing through the 22mm chipboard floor, tile adhesive & tiles. It does then stay warm and feel lovely.
http://www.thefloorheatingwarehouse.co.uk/acatalog...
However, due to the 22mm chipboard being an insulator and increasing the warm up time, for our second bathroom I am going to use the below boards, then lay a wooden overlay to tile on. Just reducing that 22mm of insulation in bathroom number 1 to around 6mm in bathroom number 2.This would be an on-joist setup, but with a minial height build up - as i am replacing chipboard with chipboard.
http://www.thefloorheatingwarehouse.co.uk/acatalog...
I see no reason why it wouldnt work/improve things. The fact that bathroom 1 is a wet room means I needed between joist insulation to allow the wetroom tray to sit on the joists & prevent a large height build up.
I know how you feel OP, I have a different system in our kitchen but that increases the height of the room by 40-50mm which I dont think your setup would lend itself to.
I will post more tonight/tomorrow when I am on my computer, but feel free to ask all & any questions. I went through it all & had the sleepless nights weighing up options when I didnt really understand it all! I feel pretty clued up now though!
As for the piping pattern, how big is your room? Are you expecting that much heat loss that there will be a significant drop in the pipe temps?
It works well in our bathroom, but does take an hour for the heat to start passing through the 22mm chipboard floor, tile adhesive & tiles. It does then stay warm and feel lovely.
http://www.thefloorheatingwarehouse.co.uk/acatalog...
However, due to the 22mm chipboard being an insulator and increasing the warm up time, for our second bathroom I am going to use the below boards, then lay a wooden overlay to tile on. Just reducing that 22mm of insulation in bathroom number 1 to around 6mm in bathroom number 2.This would be an on-joist setup, but with a minial height build up - as i am replacing chipboard with chipboard.
http://www.thefloorheatingwarehouse.co.uk/acatalog...
I see no reason why it wouldnt work/improve things. The fact that bathroom 1 is a wet room means I needed between joist insulation to allow the wetroom tray to sit on the joists & prevent a large height build up.
I know how you feel OP, I have a different system in our kitchen but that increases the height of the room by 40-50mm which I dont think your setup would lend itself to.
I will post more tonight/tomorrow when I am on my computer, but feel free to ask all & any questions. I went through it all & had the sleepless nights weighing up options when I didnt really understand it all! I feel pretty clued up now though!
As for the piping pattern, how big is your room? Are you expecting that much heat loss that there will be a significant drop in the pipe temps?
Edited by Andehh on Sunday 7th February 15:31
frg530 said:
I installed this in my conservatory:
http://www.thefloorheatingwarehouse.co.uk/acatalog...
It's like the JG stuff and runs in a serpentine. I don't have an issue with the configuration as once it's been on for 10 minutes or less you wouldn't know which side of the room the inlet is at (room is 5m x 4m). It will never match the heat retention and feel of a proper screeded floor with wet UFH. I have laminate laid on top and as you'd expect it cools off quickly but that could be a lot to do with it being in a conservatory and the type of laminate. Also you can easily tell that the pipes are at 200mm centres when you walk across it. Don't get me wrong, it does the job as best as it can I suppose but it'll never match a proper wet UFH install with screeded floor.
We have the below system in our kitchen/snug as a retrofit system and have the same warm,cool,warm,cool,where the pipes are. It's the trade off by going for the standard 'warm the slab to warm the room' or 'warm the surface to warm the room'. OP - BE MINDFUL OF WHAT YOUR FLOOR COVERING WILL BE...CARPET,TILES,WOODEN FLOORING will dictate what system you need. Not just now (you mention wood) but in 5-10 years?http://www.thefloorheatingwarehouse.co.uk/acatalog...
It's like the JG stuff and runs in a serpentine. I don't have an issue with the configuration as once it's been on for 10 minutes or less you wouldn't know which side of the room the inlet is at (room is 5m x 4m). It will never match the heat retention and feel of a proper screeded floor with wet UFH. I have laminate laid on top and as you'd expect it cools off quickly but that could be a lot to do with it being in a conservatory and the type of laminate. Also you can easily tell that the pipes are at 200mm centres when you walk across it. Don't get me wrong, it does the job as best as it can I suppose but it'll never match a proper wet UFH install with screeded floor.
http://www.theunderfloorheatingstore.com/solid-flo...
If you warm the slab you get a nice even distribution of heat, and longer lasting thermal store...but there is no real 'turning it off' just turning it dow and keeping it on. The system you and I went for is more akin to a radiator. Quick warm up, quick warm down.. It's about the only way of fitting UFH unless you can afford to dig down 100mm or so to fit the insulation & screed required.
I always use counterflow - but this is always in a 100mm concrete slab powered by a heat pump (hence only a 5 degree in/out water temperature difference).
This method ensures an even floor temp (about 23c), and an even room temp (about 21).
Experience has shown it isn't critical how the pipes are laid, the room temperature will be fine - but differing temperatures in a polished concrete floor can be quite noticeable.
Laying pipes in concrete is better, if you can't get hold of extruded polystyrene (not expanded) and staple the pipes - then you can use any layout you want.
I wouldn't use John Guest as the pipe size is unique. Use 1216 Pex pipe (no need for Pex Al Pex), then manifolds and fitting can be generic.
Note if pipe is in concrete at all the inlet temp is limited to 45. Thicker concrete leads to slower response times.
This method ensures an even floor temp (about 23c), and an even room temp (about 21).
Experience has shown it isn't critical how the pipes are laid, the room temperature will be fine - but differing temperatures in a polished concrete floor can be quite noticeable.
Laying pipes in concrete is better, if you can't get hold of extruded polystyrene (not expanded) and staple the pipes - then you can use any layout you want.
I wouldn't use John Guest as the pipe size is unique. Use 1216 Pex pipe (no need for Pex Al Pex), then manifolds and fitting can be generic.
Note if pipe is in concrete at all the inlet temp is limited to 45. Thicker concrete leads to slower response times.
It is worth considering your usage patterns, I discounted underfloor heating during my renovation partly for cost reasons, but also because, as Andehhh mentions, the heat up time is going to be slower than radiators, which can easily mean that you get minimal heat out when you're in the house in the morning, then the house stays warm while you've gone out, but is cold again when you return.
What swung it for me is that if there's time for the UFH to heat up, I'll have lit the fires, the central heating is really for getting the house up to temperature as quickly as possible.
What swung it for me is that if there's time for the UFH to heat up, I'll have lit the fires, the central heating is really for getting the house up to temperature as quickly as possible.
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