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Garage condensation
Posted: Sun Nov 24, 2024 5:12 pm
by mini_surfari
Evening!
Hopefully someone with far more experience can help…
Went out into the garage today and noticed the lower half of both minis covered in condensation to the point it’s puddling on the floor.
It’s a single garage, on a ‘new build’ (13 years old), single skin brick, side door, and up and over door. Garage isn’t attached to the house.
Any tips to solve said issue? Or where to start? Completely out of my knowledge base this one… will check the garden to see if it’s below the damp course once storm bert lets up.
Lived here 3 years and had a little condensation before but nothing like this, could it be due to plummeting temps last week, and then mild temps a day later…?
Picking up a dehumidifier tomorrow to get the cars dried out, but would like to get a Permanent solution before they start turning orange
Any of you wise folk able to help?
Cheers,
Oli
Re: Garage condensation
Posted: Sun Nov 24, 2024 5:28 pm
by politeperson
It because today was exceptionally warm for winter, so everything that was cold in your garage condensated on the warm air.
Like a cold pint of beer in the summer. The moisture runs down the outside of the glass.
Happened to me today as well. Terrible.
Luckily it is a rare occurrence so I am not going to do anything about it.
Last time I noticed it in a garage was in 2003.
Re: Garage condensation
Posted: Sun Nov 24, 2024 5:31 pm
by Pete
The extreme temp changes at this time of year (especially this week!) will cause this if you suddenly let lots of humid warmer air into a much colder garage on a day like today when it’s about ten degrees or more warmer than a few days ago. The condensation will evaporate eventually once the inside colder temp equalises with the outside warmer temp but you can’t really avoid it unless you seal your garage up and apply constant heat or do the opposite and leave it unheated and drafty which I’ve done. If your box sections are protected with dinitrol or similar and your bare metal bits and bobs are WD40’d regularly there’s little to worry about. I wouldn’t try and heat a cold garage with small fans or such as they’ll just make it worse.
Re: Garage condensation
Posted: Sun Nov 24, 2024 5:36 pm
by Peter Laidler
Yep, happened to me too. What a bast......., er....., not very nice!
Re: Garage condensation
Posted: Sun Nov 24, 2024 5:37 pm
by Mudhen
Following!
I recall my dad back in the 80s saying, 'if you ever build a garage make sure they put a thick sheet of plastic under the cement as it's hydroscopic and will absorb moisture from the ground'...not sure if that's true or not. But in 2005 when we built our house I mentioned that to the builder - he scoffed at me and I listened to him - no plastic. And now I run a dehumidifier - my tools and everything would be damp if I didn't.
I also ended up drilling a hole in the side wall to run the drain tube - found that I wasn't emptying the bucket enough so it was always playing catch up. Not sure if it helps with the electricity cost or not!
Re: Garage condensation
Posted: Sun Nov 24, 2024 5:47 pm
by mini_surfari
Glad it’s not just me then!
Coincidently not been in the garage for a week or two. Maybe I’ll look at putting a vent on the back wall to allow air to pass through?
Well I gave the engine bay a dose of ACF50 the other day, not done the back suspension or re-cavity waxed this year! Must prioritise the job if it’s dry next weekend.
Re: Garage condensation
Posted: Sun Nov 24, 2024 6:29 pm
by Oneball
Same as Mudhen. But I built my garage and did damp proof the floor and still got condensation. Carpet helps to insulate the cold concrete from the air in the garage but I still had a similar problem so I got a dehumidifier. I have it on all the time and works a treat. I’ve got one of these they seem to last about 2-3 years of continuous use.
https://www.meaco.com/products/meaco-dd ... NC4wLjAuMA..
Re: Garage condensation
Posted: Sun Nov 24, 2024 7:35 pm
by mab01uk
As Pete says leave your garage drafty in winter months and if the car has been washed or out in rain. I have a small gap under the main garage door which allows a through draught with brick air vents in the side wall but which can all be blocked up if you are working in the garage with a heater. If autumn leaves or rodents getting in could be a problem also fit some metal mesh over vents any draught gaps.
Re: Garage condensation
Posted: Sun Nov 24, 2024 8:51 pm
by haynes
How about an Air Chamber?
Re: Garage condensation
Posted: Sun Nov 24, 2024 10:32 pm
by Polarsilver
Find some old Lounge Carpet & put that on "Most" of the Garage Floor and drive car on top .. if you can make it two layers of Carpet under the Tyres so much the better.. have been doing this for many years & seems to work here.
Her indoors will be happy if you suggest that she needs a New Lounge Carpet fitted before Xmas

Re: Garage condensation
Posted: Sun Nov 24, 2024 11:14 pm
by AndyPen
Its this awful weather and I too noticed damp on the painted concrete floor today, but the carpeted bit was fine.
A couple of years ago I had this happen under a car cover too, and these days I use old bed sheets which seem to work fine as dust covers.
Re: Garage condensation
Posted: Mon Nov 25, 2024 12:33 am
by gs.davies
Re: Garage condensation
Posted: Mon Nov 25, 2024 7:25 am
by Exminiman
politeperson wrote: ↑Sun Nov 24, 2024 5:28 pm
It because today was exceptionally warm for winter, so everything that was cold in your garage condensated on the warm air.
Like a cold pint of beer in the summer. The moisture runs down the outside of the glass.
Happened to me today as well. Terrible.
Luckily it is a rare occurrence so I am not going to do anything about it.
Last time I noticed it in a garage was in 2003.
What he said……
When warm air hits cold metal and causes moisture in air to hit its dew point and turn back to water……
Not a lot you can do about it, well ventilated or a insulated and heated garage will help to extreme avoid temperature
fluctuations….
It was bloody extreme though, from minus to plus 14 over night ……
Re: Garage condensation
Posted: Mon Nov 25, 2024 8:38 am
by snoopy64
Same happened to me although my car is currently in storage, everything in my garage up to about 2ft was wet like it had been hosed down!
Re: Garage condensation
Posted: Mon Nov 25, 2024 12:47 pm
by mini_surfari
snoopy64 wrote: ↑Mon Nov 25, 2024 8:38 am
Same happened to me although my car is currently in storage, everything in my garage up to about 2ft was wet like it had been hosed down!
Exactly the same is mine, it was just pouring off.
Thanks for all the pointers, I shall get hold of some old carpet and just put it down where the two cars sit.
Along with some ventilation.
Typically everywhere locally is flooded today, so can’t pick the dehumidifier up. Will open the door and leave it open seeing as the rains stopped when I’m home this evening.
Re: Garage condensation
Posted: Tue Nov 26, 2024 10:11 am
by scalino65
I just wanted to check my thinking, i've recently rebuilt my garage, it feels nice and dry now but its quite cold. I assume its possibly a better environment for the car if its cold with a bit of airflow? I was going to try and draught proof the doors so its a nicer place for me but on reading the above, might it be better to leave it for airflow? any thoughts at all? thank you.
Re: Garage condensation
Posted: Tue Nov 26, 2024 12:15 pm
by Peter Laidler
To be really honest Scallio, it's always a good idea to leave a gap for a bit of air-flow but as Polite Person says, its nature and a bit of physics at work as per his glass of beer example and nature will always find a way round.
I'm not sure about the carpet idea to be honest. Once the absorbent carper gets wet, guess what.......? Yep, it STAYS wet for a longer time than the normal concrete floor that'll dry out in a day or two - just like mine today.
The more I listen to J O/B on LBC, the more he convinces me that it's all to do with Brexit, the EU and The Donald!
Re: Garage condensation
Posted: Tue Nov 26, 2024 12:24 pm
by scalino65
Thank you very much Peter. I shall leave it as it is and just wear some more layers when I go in there!
As for JOB - I used to enjoy his show some years ago as I liked the structure of hypothesis through to conclusion but my god you couldnt pay me to listen to it now. Many years ago, I bought a suit from him at Aquascutum in Regents Street when he was a sales assistant there. He was incredibly chippy, unpleasant and superior in attitude back then too...must have been 1994 or 5 ish...i understand he's on about 400k p.a. at LBC.....
Re: Garage condensation
Posted: Tue Nov 26, 2024 3:49 pm
by Oneball
Peter Laidler wrote: ↑Tue Nov 26, 2024 12:15 pm
To be really honest Scallio, it's always a good idea to leave a gap for a bit of air-flow but as Polite Person says, its nature and a bit of physics at work as per his glass of beer example and nature will always find a way round.
I'm not sure about the carpet idea to be honest. Once the absorbent carper gets wet, guess what.......? Yep, it STAYS wet for a longer time than the normal concrete floor that'll dry out in a day or two - just like mine today.
The more I listen to J O/B on LBC, the more he convinces me that it's all to do with Brexit, the EU and The Donald!
I found with mine that the concrete floor didn’t get wet but it did get cold and stay cold throughout the day so as the air temperature rose the cold concrete lead to a temperature difference causing condensation. Which is why the carpet helped by insulating the air from the carpet. The carpet never got/gets wet.
Re: Garage condensation
Posted: Tue Nov 26, 2024 4:21 pm
by Polarsilver
Our Garage Carpet is probably Magic as it does Not get Wet .. never has .. i have a cord back carpet ( not an Axminster ) placed straight onto the floor & that has been in the Garage use for more that 10 years .. Also use other odd bits of Carpet spread about to catch any oil spills etc & that is what gets thrown away.
If a wet car gets driven it ..i dry off the Paintwork & the odd bit of Water Drips onto the Carpet to just self dry . never been a problem with Mould or anything other that is nasty.