Garage ventilation v humidifier

[hiltonig]

Ok need some advise, going to install a dehumidifer to help with the storage of the car,If you use one of these do you need to ventilate the garage as well. Does it help having both or is there no point. The garage is well insulated and has a false insulated ceiling. The garage is also heated to maintain a low background temperature, I would be using ventilation with heat recovery.

Your comments please

Thanks

[S6 ROR]

I use an X-Dry in my garage, just keep doors and windows shut and lay a carpet/old curtain along bottom of garage doors. Dosen`t seal the garage, but stop a howelling gail blowing through.
Brought the X-Dry at the classic car show last year, and is designed to run at a much lower temperature than traditional de humid. Have been well inpressed with its performance so far. the chassis rails feel bone dry, whereas before, when you went into the garage it felt damp, and the chassis rails had condensation on them. Have a look at www.dry-it-out.com I think it cost £195

[AlexanderV8]

hiltonig said:

Ok need some advise, going to install a dehumidifer to help with the storage of the car,If you use one of these do you need to ventilate the garage as well. Does it help having both or is there no point. The garage is well insulated and has a false insulated ceiling. The garage is also heated to maintain a low background temperature, I would be using ventilation with heat recovery.

Your comments please

Thanks

My understanding is that dehumidifiers will extract moisture from everything that contains it in the immediate area - even concrete & mortar.
Industrial dehumidifiers when over specified or left on too long, have even been known to dry out the fabric of buildings too much, making them unstable! Surely then, if you allow moisture in with ventilation, the dehumidifier will work to collect that moisture, which on the face of it, seems counter-productive - you could argue in that case when using a dehumidifier, it would be better not to ventilate!
Having said that, if you have a concrete floor, it will contain moisture which isn't an ideal storage condition and so a dehumidifier could help. Better surely to seal the floor (& possibly walls) with a moistureproof barrier (or even an old carpet).

It's temperature differentials that cause moisture and your garage sounds well insulated. If it is, & doesn't have exposed mortar or a concrete floor, I personally wouldn't bother with the dehumidifier. Your ventilation with heat recovery sounds great.
You could always experiment by turning the dehumidifier on for a few days & see how much moisture it collects. If it doesn't collect much, I wouldn't bother with it.

By the way, the thread title - humidifiers - are completely different - they give out moisture!

[hiltonig]

opps didnt see that


yes the walls are thermline plasterboard and the floor is covered in dynotiles. I bought the X dry as I had the earlier version and I am very happy with the results. I guess the reason for the post is as the garage is well insulated ( including the garage doors ) is there any merit in allowing an air change whilst storing the car.

[AlexanderV8]

If there is no air movement and some moisture is present, then you could suffer mould growth. I suppose in this respect, the dehumidifier would help. If you ventilate though, this should largely inhibit that problem but the air you bring in would need to be warm (or the same temperature as the air in the room) & dry to prevent condensation.

I was quite impressed with a plastic 'bubble' to keep a car in I saw once. Controlled air was blown in and vented back out, so air was continually circulating and it was always at the same temperature. I suppose this would be the ideal, albeit not very practical in most cases!

[Allandwf]

Hi not quite an answer to the question but still relevant. In a previous existance I had a large double garage, sealed and painted floor, suffered terribly with condensation in the winter, where the mass of concrete would retain the cold, and on a warmer day the moisture in the air would condense on the floor and the car, which also seemed to be kept cold.
However now I have a draughty ramshackle rickety old wooden thing with wooden floor, while looking terrible, the car actually seems to be better for it !

[Chimjunkie]

Mine gets left outside....unloved Does that make me a bad person?

[AlexanderV8]

Allandwf said:

Hi not quite an answer to the question but still relevant. In a previous existance I had a large double garage, sealed and painted floor, suffered terribly with condensation in the winter, where the mass of concrete would retain the cold, and on a warmer day the moisture in the air would condense on the floor and the car, which also seemed to be kept cold.
However now I have a draughty ramshackle rickety old wooden thing with wooden floor, while looking terrible, the car actually seems to be better for it !

Given the choice, I would always go for a good timber building. Naturally breathable, dry, warm & insulative.

[wiz 1]

AlexanderV8 said:

Allandwf said:

Hi not quite an answer to the question but still relevant. In a previous existance I had a large double garage, sealed and painted floor, suffered terribly with condensation in the winter, where the mass of concrete would retain the cold, and on a warmer day the moisture in the air would condense on the floor and the car, which also seemed to be kept cold.
However now I have a draughty ramshackle rickety old wooden thing with wooden floor, while looking terrible, the car actually seems to be better for it !

Given the choice, I would always go for a good timber building. Naturally breathable, dry, warm & insulative.

Timber walls and roof are good timber floor not good for using jacks and axle stands on though.

[AlexanderV8]

wiz 1 said:

Timber walls and roof are good timber floor not good for using jacks and axle stands on though.

That sounds like a little gem from a fortune cookie!!

I'm sure some railway sleepers should be up to the job though!

[Barreti]

While we're on this subject, I could do with a bit of advice.

My garage roof is the corrugated asbestos/concrete stuff, which is nicely insulated. But I replaced a couple of cracked panels with the clear polycarbonate stuff. Great in the summer, but in the winter it collects condensation and drips.
Does anyone know if I should insulate this in the winter - say with that plastic covered loft insulation for instance, or is there something better I can replace it with that will still let some light in the garage - remembering its got to fit to corrugated stuff.

Thanks for your advice chaps, and to the Original Poster

[jeff m]

Heat can cause humidity if the insulation is not excellent(condensation)
Example; cold glass of larger in a warm room, moisture on outside of the glass.

I would dehumidify and not be too concerned about the temperature.

I assume this is a winter storage question and not a garage in which you will be working.

[AlexanderV8]

Barreti said:

While we're on this subject, I could do with a bit of advice.

My garage roof is the corrugated asbestos/concrete stuff, which is nicely insulated. But I replaced a couple of cracked panels with the clear polycarbonate stuff. Great in the summer, but in the winter it collects condensation and drips.
Does anyone know if I should insulate this in the winter - say with that plastic covered loft insulation for instance, or is there something better I can replace it with that will still let some light in the garage - remembering its got to fit to corrugated stuff.

Thanks for your advice chaps, and to the Original Poster

Any insulation would be better than no insulation. It would help to identify where the moisture is coming from in the first place though and then try & minimise it. For instance, portable calor gas heaters are terrible for causing condensation, as are paraffin heaters.

Couldn't you attach some double-wall polycarbonate sheets to the underside of the rafters the corrugated roof is attached to? you could also fit fibreglass wadding to the airgap but leave it out of the area you want clear.

[rigga]

I have a concrete sectional type garage,corrugated paneled roof,always used to have condensation problems before when i kept my bikes in there,fasteners would corrode over time etc...when i got the TIV thought id better do something,so sealed the side entrance door and the main up and over door as best as i could,painted the walls floor and ceiling,and purchased a de humidifier.... small 2 liter tank,but with the option to pipe out by hose so can work all the time..... i use an 18 liter container from a cold water drinks machine.... i can fill this in two weeks of use no problem depending on where i set the de humiderfier,garage now feels very dry inside with no condensation present at all.

[Barreti]

My problem seems to be mainly on these really cold mornings when the roof is covered in frost but the sun is shining on the wooden garage. It heats the inside up, causing the condensation to collect on the inside of the corrugated panels.
I have two sections of garage which do different things.

The old part - which is asbestos but covered with T&G wood and mainly lined with hardboard. That only has problems on the two clear corrugated panels I put in to replace the broken panels. Trouble is they both drip on the the TVR :GRRRR

The other new part of the garage - the workshop - has a new bitumen corrugated roof and this collects condensation all across it. Thats a right PITA because its completely kitted out with shelving so everything is getting dripped on.

My plan was to replace the clear panels in the old garage with the double skinned polycarbonate stuff, but I don't know how to join that to the existing corrugated stuff.

And to insulate the bitumen corrugated roof on the workshop in the hope that will stop the condensation forming.

Any thoughts?

[The Surveyor]

This is the worst "i've got the best garage" thread i've ever seen......

Paul

[ukcerb]

The easiest insulation material to use is called "kingspan" or "celotex". It is fireproof and comes in solid sheets of 2.4metre by 1.2metre (8 x 4 feet) and various thicknesses but 25mm would be adequate to stop the condensation on the inside of the roof. The sheets are finished both sides with a silver foil and joints can be sealed with alluminium self adhesive tape so you will end up with a brighter garage ceiling too!It can be wedged in posistion or screwed, nailed etcOn clear garage roof panels use twinwall polycarbonate sheets, again you can seal joints to the kingspan with foil tape.I have even insulated my garage 'up and over' door because the kingspan is so light it barely affects the spring assisted opening.A heater set to frost setting should then be enough to take care of car over winter.Hope this helps. Regards Tim

[so called]

Chimjunkie said:

Mine gets left outside....unloved Does that make me a bad person?

Mine gets left outside too but I still love her.

( my by garage is too narrow !?!?! )

[Bomber Denton]

Drying out a garage is one of the worst things you can do.

You need moisture in the air for the leather, wood etc to remain supple etc. Rust only forms where moisture is allowed to sit and stand, decent ventilation is the way to go, this can be done very cheaply by fitting a couple of small extractor fans to the far end of the garage wall (opposite the main door).
Taken a stage further using something like a carcoon with fans means a car put away cleaned at the end of September will come out in completely the same state the next March - if you're that way inclined??

[dvpeace]

If you drove the car you would not have this problem. If you leave it in the garage for too long rubbers will perish, things seize up regardless of what you do with the atmosphere.

What a waste of a good car and energy.