How to heat a double garage in the winter

I have a large, detached double garage that I’d like to spend some time in over the winter, working on the Street Triple. I’m wondering how best to stay warm so I don’t have to make regular trips back in to the house to make hot cups of tea for cold hands to hold.

There’s power running out there but, at the moment, only via an extension cable. I looked at something like this…

…but I’m reluctant to run something that draws a fair bit of power until the garage is connected up properly (the conduit is in - I could get an electrician to do that).

I could use propane or diesel heater. I’d prefer not to though. I’m trying to avoid any soft of fossil fuel heating and I also don’t want to introduce condensation, which I believe they can do.

Ultimately I’d like to plonk some solar panels on the roof and have the garage temperature controlled for the bikesif that would work but that’s a long term plan.

I don’t need to heat the whole space to to the point where I can work in a t-shirt and sip ocktails. Something localised to keep the worst of the chill at bay will do.

Has anyone got any advice based on your own experience?

Good idea, but not much use in winter - I’ve got 12 (360Wp), and from November through February (when you’d need them for heating) they yield on average about 40KwH p/m. Not nearly enough to power an electric heater…


I use one of these:

when I’m working in my garage (which has central heating, but I don’t want to heat the entire house just to get the garage warm).

Cheap and effective (2Kw).

I was thinking about some solution that kept a relatively low temperature in the garage that was enough to keep the condensation away. I really haven’t looked in to it but I take your point about an electric heater.

Is a 2kW heater enough in a fairly large space do you think?

You’d probably need a slightly bigger one - my garage is 20 m2, for that mine is adequate.

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You can get quite a powerful, battery operated, electric fire for the garage…

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Why not get a heated gilet instead? I bought 1 from Amazon for outdoor winter batting

Bseical Warming Heated Vest USB, Electric Heated Body Warmer, Heated Jackets for Men/Women, Washable Heated Gilet Heated Clothing, With 3 Levels Heat Settings, Heat Vest for Motorcycle Fishing Skiing

Ordered a couple of 5000 mah batteries to power it

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It’s not really the cold fridgelike temperature that keeps me out of the workshop in winter. It’s the coldness of the metal I’m working with. I’ve tried all sorts of gloves but they don’t help unless they are thick enough not to be able to hold the tools or the nuts and bolts etc.
The workshop is pretty well ventilated, away from the house and I have the clothlined roof stuff so condensation isn’t an issue. I can keep warm enough to work with a coat but once my hands get too cold I’m back indoors by the fire.
I think a heater would be ok if it didn’t cause instant global overheating due to it having to be so large to warm everything up. I just do indoor stuff now over the winter.

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I use an oil filled radiator in our double size garage.
No other insulation, although I’ve often thought about some polystyrene blocks on the insides of the doors.

The other must have for me is a pair of quilted overalls. I got a pair of Carhartt overalls off Ebay (theres a regular seller on there) and the quilting makes a huge difference.

The oil filled radiator uses a bit of electricity but its a drop in the ocean to our hot tub that runs 24/7 in the garden: that really does keep the electric meter spinning.

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I did think about that as another option. Much cheaper to run, too. The reviews on Amazon are mediocre - what’s your opinion?

I was just pondering that as well. Someone should invent a heated vest with lots of long pockets for tools.

I’ve actually got a couple of those but they’re in the house while it’s still under renovation and extension. Once that’s done I could redeploy them in to the garage. Polystyrene for insulation is a good idea. It’s a pitched roof sop perhaps blocks could be wedged in between the timbers.

I’ve got a Keis heated vest. Superb bit of kit, plugs into the bike and has extension leads that feed heated inner gloves, which too are snug.

Ive been too tight however to buy a £120 battery to use it off the bike.


Hi @Iron I assume your garage roof is steel? I would appreciate if you could advise on what the cloth you have lined your roof with. Cheers

I’ve got the steel box profile flat roof that has the cloth/absorbent stuff already stuck to the underside (it’s called dripstop). There’s also the same type of roofing with insulation already stuck to the panels. I can’t remember where I got ours (it was some bloke I talked to who worked at a roofing place so the sheets just arrived with him)
Here’s the same stuff:

There’s strips of rubber that are also installed on top of the roof timbers to follow the profile of the steel that are then secured when the roof screws are installed through the sheets.
I had trouble at the drip end of the sheets as the cloth/moisture sheet under the roof was sucking the water up under the roof when it rained. It’s really important to strip the cloth stuff off of the sheets back to the wall so that any dripping water (when it rains) falls into the guttering rather than wicking up the cloth.
As the cloth stuff under the roof is designed to hold the condensation (ie it gets wet) it must be well ventilated or spots of mould seem to form. They disappear once the sun comes out but I also used this steel roof over another workshop that was well insulated and dry. The spots were bad until I ventilated the room really well.
If you already have a problem with drips off of a steel roof then I suppose you could get the absorbent material and stick it to the underside when it’s a bit warmer. The cloth/absobent material doesn’t stop the condesation it just keeps the water in it and stops it dripping.

Thanks @iron that is really helpful :slightly_smiling_face:

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Just a thought, if the garage is detached could a small log burner work? I’ve got one in our conservatory and it’s amazing. Efficient and clean burning. The flue length is the big decider…we had to run our up the gable end of the house but on our house, this worked perfectly.

Possible, I guess, but probably not practical enough. By the time everything’s heated up I may well have finished what I was doing. I’m not particularly keen on wood burners in general, which doesn’t help… :slight_smile:

I’ve thought about making one of these

but they do take a while to get going and then you can’t just walk away and leave them. All that flamable stuff around too. But they are cool :slightly_smiling_face:


For a two bay standard garage that is insulated that might be enough, if you can get a heat pump exchanger unit those don’t need as much power (because they pull thermal energy from outside air, like a reverse a.c. system). Those are becoming more common but aren’t always the best option.

Radiant heaters are better for heating materials/tools instead of just the air. If you move to Iceland you can use geothermal hot water for radiators and floor/patio heating to melt the ice.

Other option is you could get a heat lamp for workbench and then have a pet dragon lizard there too!

I used mine through last winter without any issues. They’re not exactly top quality/robust but if you put it under some overalls etc I recon you’d be fine.

These are all excellent suggestions. I would move to Iceland but have you seen the price of beer over there? :laughing: