Reducing Condensation in Garages

[catceefer]

I am not sure whether this is the best place for the question, so please feel free to move it if elsewhere is more appropriate.

I have a typical 1950s prefab garage with walls made from concrete slabs bolted together, a corrugated asbestos roof, a concrete floor and wooden doors. The problem is that in this warm, damp weather, it gets chronic condensation, with everything becoming covered in a fine film of moisture, like dew. I do not use a parrafin or gas heater, so this is not a contributory factor.

Has anyone found an effective way to cure this, short of demolishion?

Regards,

James.

[mervin]

some ventilation of some sort will help, other than that a dehumidifier will go some way to getting rid of it ,
dry lining may help as well

[catceefer]

some ventilation of some sort will help,

That is what I would have thought and why I am alittle puzzled as a gale blows through a hole near the bottom of the front door, under the side door and under the eaves, through the corrugations.

Regards,

James

[Codger]

this question was asked on another forum , with a lot or replies

people were sugesting dehumidifiers and all sorts ,

however one person came up with a cheap(ish) solution that worked,

stage one: ensure that there is adiquate airflow thru the garage ,

stage two: connect a fan , the ossolating type , thru a time switch and set to run 1/2 hr on , 1 hr off , this will move the air thru the garage and assist with removing the damp

[Zunspec]

I found my bikes in just the same condition last night, all covered in "beaded" condensation. This is in an attached brick garage and it also has what I thought was adequate ventilation. I put it down the recent rise in temperatures and the metal of the bikes still being cold. Condensation looks OK on a glass of cold beer but not on your bikes. I wiped them down and then pointed my fan heater at them for a few hours.

Cheers Zunspec

[triumph5ta]

James your analysis is correct, warm damp air, cold surfaces = condensation.

You really need heat AND ventilation. You need to keep the bikes at a temperature above the "dew point" where moisture in the warm damp air will settle on the bikes as condensation. This is not easy to calculate and depends on the humidity of the air and its temperature and the temperature of the bikes. Not something you want to keep working out in an old garage. You want ventilation to move damp air out but you dont want so much that the temperature/humidity goes up and down all the time.
You cant really get rid of it unless you store your bikes in a posh brick built structure that will stay at an even temperature. Its no co-incidence that museums are generally big stone buildings capable of maintaining an even temperature thus minimising condensation on their collections.
If you can afford to run a fan heater on its lowest setting then that will help but it really needs to be on all the time. Covering the bikes with sheets to help keep their temperature stable will help but your really fighting uphill if you have a thin walled structure.
I use a fan heater on a timer to move air around a couple of times a day, sheets on the bikes and plenty of WD-40 on chrome parts etc.
This will minimise condensation but will not eliminate it.

I need to write a paper on "the preservation of motor vehicles in unheated storage facilities"...

[Detour Rd.]

Warm damp air? You guys are lucky. Hasent been above freezing for weeks now with a foot of hard pack snow on the ground.

[catceefer]

Codger: I found the posts on the "other forum". Thank you.

Thank you all for the replies and suggestions.

Opinions seem divided between venting the moisture out, mechanically removing it and keeping it out in the first place.

Any form of heating or electrical dehumidifiers are out due to the cost: our electricity bill is high enough as it is.

The garage already has plenty of ventilation, with air coming under the doors and leaving through the eaves. Yesterday, I left the doors all open to allow the wind to blow through, but it made no difference.

I feel on balance that my best plan is:

Make the doors more draught-proof
Use some 1/2" plastic boarding that I have been offered to line the roof
Block up the corrugations around the eaves
Put down a plastic DPC sheet and lay either some plywood or cheap lino on floor

The actual walls, oddly, never have any evidence of damp on them at all. I'd like to line them, but cost might prohibit this.

Fingers crossed that this will at least reduce the problem a bit.

Regards,

[supersix]

Read up on the properties of the roofsheets! Apparently the corrugated sheets hold the condensation till it evaporates. You may find that plastic drips it onto your bikes etc.
I came upon this strange info looking for a supplier of new sheets for my Dad's garage. Google cement fibre roofsheets. You'll find the info in there somewhwere!

Supersix

[sfb]

I wasn't sure about the idea of plastic sheets.

I used polystyrene sheets in the roof of my shed and that seemed to sort any condensation problems. It's a metal shed with corrugated roof.