Motoring Discussion > Reducing condensation in garage	Miscellaneous
Thread Author: Dave	Replies: 37

Tue 12 Oct 10 08:46   Reducing condensation in garage - Dave

It's not really a garage, more a barn. But at this time of the year I suffer a lot of condensation. It's reasonably well ventilated because of its constrction, but still the problem persists. There's no way I can insulate it or anything. So am I better off trying to add more ventilation, even forced, as a means of trying to keep the stuff inside (cars, tools etc) closer to the outside temperature as it goes up and down? I'm assuming it's the temperature differential between the 'stuff' and the air that causes the water problem, where the air temp drops quicker than the temp of the cars etc. Reply to this message | Report message

Tue 12 Oct 10 08:55   Reducing condensation in garage - Collos

Condenstaion occurs when the temp drops below the dew point no amount of more ventilation will cure your problem,the solution perhaps not practible is a little heat to lift the temp. Reply to this message | Report message

Tue 12 Oct 10 09:07   Reducing condensation in garage - Tooslow

He's right. I took a can of preservative out of the shed the other morning. It was covered in condensation. I'm sure the inside of the shed must have been at a similar temperature to the outside but the temperature of the liquid in the can? That's going to go up and down at it's own rate. So a little heat would seem to be needed, though that may be impractical / uneconomic. Insulation, even without heat, would slow the rate of temperature change thus allowing the contents time to cool / warm in response to the ambient temperature and so reduce or avoid condensation. John Reply to this message | Report message

Tue 12 Oct 10 09:24   Reducing condensation in garage - L'escargot

>> ......... the solution perhaps not practible is a little heat to lift the >> temp. >> You need to extract the moisture from the garage and heating it won't do that. Buy a dehumidifier. Reply to this message | Report message

Tue 12 Oct 10 09:40   Reducing condensation in garage - CGNorwich

You need to extract the moisture from the garage and heating it won't do that. Buy a dehumidifier. The problem with that in the typically UK situation where a cold crisp night is then followed by a change to milder wetter weather you will end up trying to de-humidfy the entire atmosphere. The condensation will stop naturally when the garage and its contents rise to the same temperature. The de-humidifier will make no difference (except to the electricity bill). Reply to this message | Report message

Tue 12 Oct 10 20:14   Reducing condensation in garage - MD

>> >> ......... the solution perhaps not practible is a little heat to lift the >> >> temp. >> >> >> >> You need to extract the moisture from the garage and heating it won't do that. >> Buy a dehumidifier. >> He said it's A BARN!! What is a ruddy dehumidifier going to do?? Reply to this message | Report message

Tue 12 Oct 10 20:23   Reducing condensation in garage - R.P.

Use up fossil fuels and promote global warming and turn Sweden into a Mediterranean climate thus solving the problem Reply to this message | Report message

Tue 12 Oct 10 20:29   Reducing condensation in garage - Runfer D'Hills

I think it was the venerable Clarkson who suggested we all buy Range Rover V8s to heat Britain up. The additional personal costs would be offset by obviating the need to go abroad on holiday to guarantee warmth ! Reply to this message | Report message

Tue 12 Oct 10 09:20   Reducing condensation in garage - L'escargot

Buy a dehumidifier ~ a proper one which incorporates a refrigeration unit. I garage my car soaking wet and it's bone dry the next morning. My dehumidifier is a De'Longhi DEM 10. tinyurl.com/24xjg7p Reply to this message | Report message

Tue 12 Oct 10 09:26   Reducing condensation in garage - CGNorwich

It not the air temperature dropping but the air temperature rising. The garage and its contents cool down through the night. In the morning the outside air temperature warms up and warmer air which can carry more moisture than cold enters the garage. When this moist air encounters a cold surface such as a car the moisture is precipitated, The only cure is a ventilation plus warmth - expensive! Yourr car will probably suffer less if left out all night Reply to this message | Report message

Tue 12 Oct 10 09:34   Reducing condensation in garage - L'escargot

>> The >> only cure is a ventilation plus warmth ......... We'll have to agree to disagree. Note that I make my recommendation of a dehumidifier based on actual working experience, not theory. >> Your car will probably suffer less if left out all night >> It will be more vulnerable to theft and vandalism. Reply to this message | Report message

Tue 12 Oct 10 09:43   Reducing condensation in garage - CGNorwich

Note that I make my recommendation of a dehumidifier based on actual working experience, not theory. Ye cannae change the laws of physics! Reply to this message | Report message

Tue 12 Oct 10 10:22   Reducing condensation in garage - Tooslow

CG, you missed "Captain" off the end. :-) John Reply to this message | Report message

Tue 12 Oct 10 20:19   Reducing condensation in garage - MD

>> Ye cannae change the laws of physics! >> Snail can!! Dehumidifiers ain't worth a W! Yours MD. 34 years in Construction and 21 years in Damp-Proofing and associated trades. Warmth and Ventilation. Most of the rest is snip! - please refrain from using similar rhyming words to get around the swearfilter. And I talk my way OUT of a lot of work by telling prospectives the TRUTH. Last edited by: Webmaster on Thu 14 Oct 10 at 09:53 Reply to this message | Report message

Tue 12 Oct 10 09:42   Reducing condensation in garage - Dog

I have no remedy for your situation, I'm just telling you mine ... My garage is rendered block under a pitched tiled roof & felted, the doors are wood bi-folds. I have a window at the side and I leave the fanlight open, There is no insulation whatsoever and I never suffer from condensation, Experience from living in a barn perversion at one time taught me that heat *and* ventilation was a must. Reply to this message | Report message

Tue 12 Oct 10 11:32   Reducing condensation in garage - bathtub tom

It's a combination of temperature and humidity. The OP states the barn's well ventilated, so no amount of de-humidifying's going to change things, as the air you dry is going to be replaced with moist air from outside. The solution to that is seal the inside from the outside if you want to use a de-humidifier. If you raise the temperature then the air can hold more moisture, however the barn's well ventilated so that's difficult. A neighbour approached a similar problem by putting a greenhouse heater under his covered motorbike that was kept in a large, well ventilated building. The 'bike was kept a few degrees warmer and as a result and water didn't condense on it. Reply to this message | Report message

Tue 12 Oct 10 11:40   Reducing condensation in garage - madf

Put your deep freeze and a fridge in the garage. They give off enough heat to warm it a little... Our garages are well ventilated - gaps round the doors. And an insulated roof means they retain some warmth.. Consequently altho' we get lots of damp weather and lots of winter frosts, condensation is not an issue. But then it's stone built with a considerable thermal mass so rapid heat changes just do not occur.. Condensation is worst in low thermal mass building with rapid temperature changes.. as any physicist will tell you.. Last edited by: madf on Tue 12 Oct 10 at 11:42 Reply to this message | Report message

Tue 12 Oct 10 11:43   Reducing condensation in garage - Boxsterboy

Yes, the OP needs to seal his barn before thinking of dehumidifying. Once sealed he will need to insulate the barn well and then heat it. Unfortunately the solutions to his problem will leave him a lot poorer! Reply to this message | Report message

Tue 12 Oct 10 13:05   Reducing condensation in garage - Slightlyfatdirector

I wanted to keep my XJ-S convertible in a single garage I have. It has a flat roof and is single-skin construction with no cavity wall, no insulation and it is detached from the house. Simple metal door and lots of gaps arround. I bought an oil fired radiator and set it to keep the inside of thew garage above freezing, which it did well. The garage also contains a couple of fridges and a freezer too and this radiator kept the condensation off their front doors which was handy. All in all I was pretty pleased. The only problem? When I got my energy bill it had literally doubled our overall energy cost for the whole property by this blasted radiator! My wife was suitably impressed! (although I pay for it)! And I only had it running for a couple of months as the car was in a businesss garage for some work for a few months. I may try just leaving it alone under a breathable cover in the unheated garage this year to see if that helps. Reply to this message | Report message

Tue 12 Oct 10 13:16   Reducing condensation in garage - Collos

Dehumidifiers only remove moisture they do NOT stop it forming ,when the inside temp drops below dew point then condensation forms,Many years of designing HVAC systems for buildings all round the world is my experience.Just about all public and and large buildings use a BMS system set with fabric protection this can vary depending on its location but 5 degree c for fabric and 1/2 for frost ,for frost you only need the pumps to run at first stage as moving water is more difficult to freeze second stage fetches the boilers in it then works through the OAT to keep a constant inside temp above freezing and due point.In summer when there is no or little chance of frost in most areas of the UK then only fabric protection(above dew point) is used Reply to this message | Report message

Tue 12 Oct 10 13:25   Reducing condensation in garage - Dog

I found this to be of interest ~ www.meaco.com/condensation.html Reply to this message | Report message

Tue 12 Oct 10 13:34   Reducing condensation in garage - Collos

I wish they did only cost 2/3 pence an hour to run,for a large building its more like 3 pence a square meter as the contributer above found out . Reply to this message | Report message

Tue 12 Oct 10 13:45   Reducing condensation in garage - Dog

Fair point Collos, how about this advice then ~ www.ehow.com/way_5839709_garage-condensation-problems.html Reply to this message | Report message

Tue 12 Oct 10 14:37   Reducing condensation in garage - Bigtee

Can you fit windows in the sunny side were you get most sun & then have windows open a little as the sun heats up the moisture it will evaporate. Reply to this message | Report message

Tue 12 Oct 10 15:44   Reducing condensation in garage - Dog

>>Can you fit windows in the sunny side were you get most sun & then have windows open a little<< Brilliant idea BigT, wouldn't work here in Cornwall though - its not Sunny at night. :) Reply to this message | Report message

Tue 12 Oct 10 16:53   Reducing condensation in garage - Collos

That really appeals to my sense of humour Reply to this message | Report message

Tue 12 Oct 10 17:26   Reducing condensation in garage - Dave

Thanks guys - I guess there's not much I can do about it. It's wooden construction with plenty of gaps. It's also a fair size - big enough for 3 cars with room to spare, and a high pitched roof. Trying to get any sort of heat into the place may be a bit prohibitive cost wise due to the size and outside temperature (this is Sweden), although once it's properly cold outside and permanently below freezing, then it's not so much of a problem. Reply to this message | Report message

Tue 12 Oct 10 20:55   Reducing condensation in garage - Fenlander

As a matter of interest Dave where is the condensation forming and what is the floor construction? Reply to this message | Report message

Tue 12 Oct 10 21:10   Reducing condensation in garage - Dave

The condensation is on anything metal - the cars, tools, snow blower, lawn mower etc. The floor is thin concrete with no vapour barrier or anything. The floor does get damp, although I'm not sure whether it's coming from above or below - probably both. Once the temperature drops and stays below zero, usually from the end of november untill march sometime, there's no problem! Reply to this message | Report message

Tue 12 Oct 10 22:50   Reducing condensation in garage - Fenlander

Asked as we have 7 different outbuildings all of different construction. There are big differences as to which suffers the most damp/condensation and it's not always easy to know why. What does seem to be true though is those with the poorest floors in terms of resisting rising damp are the worse. My car is never condensation covered though but in the same building tools like exposed socket sets are covered with condensation on a very cold morning. The least damp building was built as a stable, has a concrete floor with dpm, is well sealed at door and windows (d.glazed) apart from inlet/outlet vents at topmost roof level. Also has 20mm rubber flooring mats and a double roof/wall construction of box profile tin sheets on 18mm board. Last edited by: Fenlander on Tue 12 Oct 10 at 22:50 Reply to this message | Report message

Wed 13 Oct 10 07:36   Reducing condensation in garage - L'escargot

"It's not really a garage, more a barn." Several members have suggested heating the garage, but that will merely transfer moisture from the structure of the garage into the air inside. It would help if you told us the dimensions of the garage. Last edited by: L'escargot on Wed 13 Oct 10 at 07:38 Reply to this message | Report message

Wed 13 Oct 10 07:39   Reducing condensation in garage - L'escargot

Mods, it looks as if posts that have been edited get a large space between paragraphs. Reply to this message | Report message

Wed 13 Oct 10 08:57   Reducing condensation in garage - Cliff Pope

Dehumidifiers work excellently if you have a sealed garage no bigger than necessary for the car. That stops damp air getting in, and you only have a finite quantity of air to dry out. Dehumidifier plus ventilation is a pointless waste of money. I keep my cars in a large barn. It is not so much ventilated as draughty, and I get no condensation. If a car has been used and put away hot, it stays warmer than its surroundings all night, so everything else attracts the damp air, not the car. Reply to this message | Report message

Wed 13 Oct 10 08:56   Reducing condensation in garage - Dog

Dave ole son, I reckon your problem is caused by the thin concrete floor with no vapour barrier. My 6 inch block (unheated) garage with pitched tiled roof is always bone dry, My previous property had a large (unheated) wooden summerhouse in the garden which was always bone dry, Until you get that floor sorted *properly* you'll continue to have a condensation problem. I didn't space the text out with large gaps as it appears here??? Last edited by: Dog on Wed 13 Oct 10 at 08:59 Reply to this message | Report message

Wed 13 Oct 10 09:01   Reducing condensation in garage - Cliff Pope

>> >> >> Until you get that floor sorted *properly* you'll continue to have a condensation problem. >> I'm not so sure about that. Mine has an old inspection pit running the full length with running water at the bottom. It doesn't seem to cause any damp problem. I think you just need more ventilation, as in "gale blowing through". Reply to this message | Report message

Wed 13 Oct 10 09:06   Reducing condensation in garage - Dog

>>I think you just need more ventilation, as in "gale blowing through"<< Perhaps we need to send Martin over to check it - he could do with a holiday :) Reply to this message | Report message

Wed 13 Oct 10 09:49   Reducing condensation in garage - madf

I too have an inspection pit that is damp.. as in rotting away railway sleeprs placed across the pit I recall my father having a small wooden garage: half rotten and earth flooor. No condensation there.. But as it had so may holes, there was always a gale through it... :-). Reply to this message | Report message

Wed 13 Oct 10 09:45   Reducing condensation in garage - L'escargot

>> I didn't space the text out with large gaps as it appears here??? Goodness knows what will happen with iffy's posts! His are a step ahead to start off with. ;-) Reply to this message | Report message