Classic cars forum & vehicle restoration.

[admin]

Whenever we have a period of foggy nights, I go into the garage next day and find everything misted over with dampness. The garage (corrugated roof) is well ventilated along the sides (thanks to the profile of the roofing allowing air in), and has quite a sizeable gap around the main doors - perhaps too big a gap. I had thought that lots of ventilation is a good thing, but perhaps I've got too much and the foggyness outside gets in too easy and thats whats making surfaces damp in there?

I used to run a dehumidifier in there but since that went u/s I don't use anything. Would I be better off covering over the gaps around the main doors, lessening the ventilation a bit but perhaps lessening the ingress of damp air into the garage?? all thoughts welcome

Rick

[buzzy bee]

To stop condensation you need to be more sealed up I would have thought, and even insulated, but then if you put anything damp or wet into the garage the dampness, will not be able to escape!

I think a healthy balance would be good.

Not sure I am right but that is what I would do!

Cheers

Dave

[vx4/90]

Hi from me BTW, I'm new here!

Although many people think ventilation is the answer to condensation, it's not the whole story. When you see your lawn covered in dew in the morning, that's condensation, and you couldn't get much more ventilated than an open garden. To combat it in my garage I've sealed up all the gaps and I run a dehumidifier. The air now just circulates within the garage, getting drier each time it passes through the dehumidifier - I've got a cheapo humidity meter, and it generally reads about 10% less RH in the garage than ambient. Hope that helps.

[buzzy bee]

I supose like vx4/90 has stated if you seal up like I said, then youran a dehumidifier, you then give the damp somewhere to go should you have to put a wet car away.

Cheers

Dave

[admin]

Hi again vx

yeah I might end up doing that, quite a lot to seal up but worth it, especially with bare metal around and I should really find out why the dehumidifier has stopped working, its not even very old

R

[Uncle Joe]

I can agree with the comment about sealing the gaps, but it shouldn't be done so that the place is airtight. Put in a small radiator, and a humidity controlled extractor fan.

Thats what I have done, and it works perfectly! In my case, maybe a little to well, as I've never actually seen / heard the fan running!

[admin]

Looks like I need to find a lot of rags then to stuff into each corrugation in the roofing sheets

Rick

[Uncle Joe]

Or Gaffa tape (hehe)!

Did you know that it is possible to modify a refrigerator to use a means of controlling humidity? Dunno what your Maud* will say though!

*your Maud: Northern equivalent of 'er indoors!

[Castellated nut]

If your roof is old weathered corrugated asbestos, you may well find that it is porous, in which case nothing is going to keep the damp out.

If you seal up all the gaps you do need to run a dehumidifier, or you will just make things worse. Equally if you run a dehumidifier you do need to seal all the gaps!

I use a dehumidifier, and like vx4/90, I find that the RH is about 10% reduced (on a good day). Most of the time this seems to be good enough to keep condensation off the metalwork. Of course, if you can make a really good job of the sealing, you should be able to reduce the humidity even further.

[admin]

Hi castellated

the roof is corrugated metal, with a few clear sections to let light in.

I suppose if the worst gaps are blocked up, with just enough to allow circulation, it'll be a reasonable balance. The biggest offenders are the 2 front main doors, they have Large gaps around them, because they are set a few inches inside of the front fascia when closed. I need to have a meander around a DIY store and see what flexible sheeting might work for bridging the gap.

Rick

[buzzy bee]

You could use something like butile rubber, simmilar stuff to pond liner!

Cheers

Dave

[admin]

right, I'll have a look for some - sounds like the kind of stuff I was thinking of, it could be cut into strips and tacked along the side walls to block the gap between roof and walls, and also used about/around the main doors

R

[Uncle Joe]

Rick, we have major problems here with condensation on water pipes. To combat this, we lag them with a kind of foam rubber, one kind for hot, another for cold. The 'cold' rubber is also available in self-adhesive sheet form for corrugated metal roofing. So a trip to a plumbers supply, or DIY store should solve the problem.

[admin]

yup I think a shopping trip this week might be in order

R

[rustyreks]

Rick you obviously need to move to a place with a better climate with less humidity i hear australia or new zealand are good places for cars we dont use salt on our roads so less rust something to think about.