Underfloor Heating in a garage ? Anyone done it ?
Underfloor Heating in a garage ? Anyone done it ?
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Discussion

catfood12

Original Poster:

1,530 posts

162 months

Monday 4th May 2015
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Doing large rebuild including garage. Old garage was cavity walls and double glazed, so reasonably warm. Building new one with thermal blocks, cavity insulation and warm roof. Also putting insulation on the floor.... so why not UFH too ?

Anyone else done this, or can suggest if a it's a good idea or bad ?

Engineer has said they work on same floor loadings for house and garage. Flow screed man is suggesting 75mm screed in garage of a different material than the 60mm screed that is going in the house.

rb5er

11,657 posts

192 months

Monday 4th May 2015
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No problem really, dpm, insulation, polythene to protect insulation, UFH then screed. UFH to new manifold, manifold connected to hot water feeds. Make sure your boiler is man enough though.

Steve H

6,561 posts

215 months

Monday 4th May 2015
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Only real question is whether it's worth the cost of installation and running for a building that you may not spend that much time in.

Discopotatoes

4,101 posts

241 months

Monday 4th May 2015
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I've just built my own extension with integral garage and I'm using kickspace heaters in the garage under the work bench which blow warm air under the car

chippy348

689 posts

167 months

Monday 4th May 2015
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I have a large garage build in the pipe line (20m x 8m) and i will have wet underfloor heating, think the spec was hardcore, 150mm of concrete then 100mm insulation pipes clipped to that and then 75-80mm of screed.

I will have a mix of car traffic and heavy machinery.

If you do a search on here there are 2 threads from people who have done it.

The cost is not that much in the grand scheme of things

C Lee Farquar

4,139 posts

236 months

Monday 4th May 2015
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I wish I'd done it in my workshop.

Personally, I'd lay the pipes in the slab and not have a screed.

EddyP

867 posts

240 months

Monday 4th May 2015
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C Lee Farquar said:
I wish I'd done it in my workshop.

Personally, I'd lay the pipes in the slab and not have a screed.
This is what I'm thinking of doing, and then connecting it to a log burner back boiler in the workshop. Not sure if there's any reason not to?

Pheo

3,492 posts

222 months

Monday 4th May 2015
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isn't the warm up time going to be a bit annoying? How long are you in there for?

caziques

2,787 posts

188 months

Tuesday 5th May 2015
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Done plenty of garages with underfloor in the last few years.

Pipe spacing can be generous (unless you want to get it to 25), ie 300 spacing rather than 150.

We usually do a double garage with 100 metres of pipe.

Note if you are using a boiler for the heat source the temperature of the water going into concrete shouldn't be more than 45, so you'll need some sort of tempering valve.

fttm

4,249 posts

155 months

Tuesday 5th May 2015
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Bit of food for thought from Canada , when temps are below freezing and you bring a car into a heated garage the condensation is dreadful , fuel tanks / pumps for a start . Admittedly our winters are a tad more harsh and longer but give it some thought ,know you guys have a liking for winter tires nowadays LOL .

stuart313

740 posts

133 months

Tuesday 5th May 2015
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Why not do this to your grass whilst you are at it.


catfood12

Original Poster:

1,530 posts

162 months

Wednesday 6th May 2015
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Steve H said:
Only real question is whether it's worth the cost of installation and running for a building that you may not spend that much time in.
Is that you sweetheart posting in secret ? As I've told you, it's the most important room in the house.

chippy348ts said:
I have a large garage build in the pipe line (20m x 8m) and i will have wet underfloor heating, think the spec was hardcore, 150mm of concrete then 100mm insulation pipes clipped to that and then 75-80mm of screed.

I will have a mix of car traffic and heavy machinery.

If you do a search on here there are 2 threads from people who have done it.

The cost is not that much in the grand scheme of things
Magic. That's confirmed the spec. The re-inforced slab is down. 100mm Recticel on it's way. Flow screed fella is doing some 75mm fibre re-enforced screed.

Pheo said:
isn't the warm up time going to be a bit annoying? How long are you in there for
I kept the heaters on in the old garage. Italian V12 and an old Ford to keep comfy. It will stay warm. Just cost less to do so now.

fkstick said:
swear filter test. That works well then. I've always wondered :-)
caziques said:
Done plenty of garages with underfloor in the last few years.

Pipe spacing can be generous (unless you want to get it to 25), ie 300 spacing rather than 150.

We usually do a double garage with 100 metres of pipe.

Note if you are using a boiler for the heat source the temperature of the water going into concrete shouldn't be more than 45, so you'll need some sort of tempering valve.
Super. Thanks for the useful info. I've just ordered another Henco manifold and mixer/pump assembly. Will put this in same as the rest of the house, but wider pipe spacing.

fttm said:
Bit of food for thought from Canada , when temps are below freezing and you bring a car into a heated garage the condensation is dreadful , fuel tanks / pumps for a start . Admittedly our winters are a tad more harsh and longer but give it some thought ,know you guys have a liking for winter tires nowadays LOL .
Ha ! I used to work in Chelmsford. MA, not Essex. I know about the cold winters. I'm in the south of the UK, so worse case if I take them out in winter, it's leave the windows open for a day or so.

catfood12

Original Poster:

1,530 posts

162 months

Thursday 15th October 2015
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Done.

New garage built, 100mm Celotex in the floor & warm roof, new Alutech sectional door, hi-spec windows, thermals on the inside, full fill cavity insulation and underfloor heating to keep my babies warm !




sealtt

3,091 posts

178 months

Thursday 15th October 2015
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Cool, was the idea to keep the cars at a regular temperature or for you to stay warm using it as a workshop in there, etc?

Demonandrew

1 posts

45 months

Wednesday 30th March 2022
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I am just preparing to start work on a new build detached garage/workshop at the bottom of my garden. I like the thought of underfloor heating as I spend a lot of time laying on the floor under my classic campervan year round. I have been wondering if underfloor heating would withstand the weight of cars on it. Also considering solar panels on the roof for electricity. Located in the South of England.

caziques

2,787 posts

188 months

Wednesday 30th March 2022
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Underfloor pipes, definitely.

The lowest capital cost for heating would be straight electric - the lowest running cost with reasonable capital cost would be a small hot water heat pump.

A 3.5 kW unit runs at around 800 watts.

The problem in the UK would be finding such a unit at a decent price.

theboss

7,343 posts

239 months

Wednesday 30th March 2022
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FWIW I have a 550kg piano resting on brass casters on screed and the weight / contact patch will be massive compared to a vehicle.

It hasn't collapsed yet smile

Edited by theboss on Wednesday 30th March 23:21

Hectorsmector

2 posts

1 month

Monday 3rd November
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Hi, wondering how you guys got on with wet UFH in garage? Would appreciate feedback as we are about to build garage and seriously considering this for number of reasons. Spend at least 3-6 hours in current ( freezing workshop/ have an old Triumph/ daughter is athlete and trains in outside gym 6 hours a week…which is an old polytunnel….its baltic and not great in winter.
We are definitely using wet UFH, as upstairs of garage will be an office/ hobby room….using ASHP from nearby house build. Thinking of insulating floor and walls to “accommodation standard”.
What not sure of is how thick floor above ufh has to be to enable car use.
Welcome advice and experiences.