Garage condensation - ventilation?

[Phil_D]

My garage workshop (now a home gym/workshop) suffers from condensation in the winter where things like metal weight plates are visibly wet.

My garage something like 16 x 12ft with 2 of the walls actually being retaining walls as it’s cut into a hillside. The rear wall is visibly damp which presumably stems from water being pushed through from the earth behind. It’s not too bad just in a couple of places you can see where it eventually runs down the wall where it looks like whatever it was tanked with has failed in a couple of small places. I don’t feel this is a real drama though.

The roof is GRP sat on OSB with no insulation, and actually due to headroom constraints I don’t really want to insulate even between the joists as there’s literally just a few cm clearance for various overhead gym movements as it is!

there’s no real ventilation to speak of. Do you think adding a vent of some sort would significantly improve things or would I just be p*ssing into the wind?

can add some pics in the morning if it seems unclear!

 

[brightspark]

depends on what your budget is and how far you go . re tank the wall insulate it a bit of hearing and ventilation or a dehumidifier and heat

 

[Pete.]

Turf the roof?

 

[Phil_D]

depends on what your budget is and how far you go . re tank the wall insulate it a bit of hearing and ventilation or a dehumidifier and heat

I’d like to keep it cheap as it’s not a huge issue, defo don’t want to be heating the garage. Just been in there this morning and there wasn’t really any condensation so I think it’s just certain weather conditions that cause it.

There’s a little hatch window I can leave open a few inches (I’m not sure why I didn’t think of this earlier) to try and improve ventilation, I think my budget would stretch to putting a vent in the wall of needed but really want to keep costs down on this one

 

[123hotchef]

I just banged a leccie dehumidifier in mine switches on and off when it needs too I do have to empty it every day or 2 I should hook it up to drain outside but the water is good for other things

 

[cheb]

Would a dehumdifier be a better option? Beware, some of them don't work in cold rooms.

 

[Phil_D]

I just banged a leccie dehumidifier in mine switches on and off when it needs too I do have to empty it every day or 2 I should hook it up to drain outside but the water is good for other things

Would a dehumdifier be a better option? Beware, some of them don't work in cold rooms.

I feel like due to the retaining walls a dehumidifier would be working overtime 24/7. Have you figured out how much it’s costing you to run?

which one did you go for out of interest?

 

[cheb]

I bought a Meaco Zambezi for the shed. Cost? I don't know, but it gets emptied twice a day in the winter. It's damp up here and the shed door faces south so gets the worst of the weather.

Meaco claim 10p/hour running at full power, based on 15p/kWh.

 

[123hotchef]

no idea how much it costs me to run it how work I work that out? do I need to check the draw with a amp meter?

The one in the workshop is a old one I picked up for free, I do have a better up to date one in the house.

 

[Dr.Al]

I've got an eco-air dessicant dehumidifer connected up permanently in the garage (with the drain pipe going out through a hole in the wall). The dessicant dehumidifiers are the ones that are supposed to work to much lower temperatures I think (that was one of my criteria as it is in an unheated garage).

It has a "humidistat" built in, so turns on when the humidity goes over a certain level (which you can select with a dial on the top). I have it set so that it doesn't try too hard (to save money, although I've no idea what it costs to run). I had a lot of rust issues when I started using the detached single garage for metalwork; I haven't had any problems at all since the dehumidifier's been there.

My attitude was that it would take a lot of years for the cost of running a dehumidifier to be more than the cost of replacing all my machine tools after they ended up being a pile of rust in the corner!

 

[minimutly]

Definately dehumidifier. I live on a foggy west facing hill, the low cloud blows in through all the crevices all winter. So around October I put the machine on, it stays on until April, depending on the weather. I empty two litres a day sometimes. It works well, wouldn't be without it.

 

[Ashley Burton]

Can the soil be retained that lays against the garage wall?

I would remove that problem with the moisture getting through the wall.

Then I would insulate, But it really does depend on how far you want to go with things...

 

[knighty]

if you don;t care about it being cold (you use is a a gym tho?) - a fan blowing in or out through that window will fix all your problems

A desiccant dehumidifier will dry it out too, but cost more to run - as a bonus it'll take the chill out of the place too

iirc my desiccant dehumidifier at work (it's just a little home dehumidifier) uses 600 watts so about £1.70/day to run (wow I didn't realise it was that much) - but mine is set to run 24/7.... if yours isn't that damp you can set it to a higher humidity setting... so it'll run as a fan 24/7 and dry the air as/when needed :-)

as above... it's cheaper to run a dehumidifier than replace all your stuff!

 

[garethp]

Would a dehumdifier be a better option? Beware, some of them don't work in cold rooms.

Dessicant type work down to around 1 deg c

Compressor types aren't much use below 10 deg c as they freeze up and need to go into a defrost cycle

 

[123hotchef]

Mine freezes up

 

[Phil_D]

if you don;t care about it being cold (you use is a a gym tho?) - a fan blowing in or out through that window will fix all your problems

A desiccant dehumidifier will dry it out too, but cost more to run - as a bonus it'll take the chill out of the place too

iirc my desiccant dehumidifier at work (it's just a little home dehumidifier) uses 600 watts so about £1.70/day to run (wow I didn't realise it was that much) - but mine is set to run 24/7.... if yours isn't that damp you can set it to a higher humidity setting... so it'll run as a fan 24/7 and dry the air as/when needed :-)

as above... it's cheaper to run a dehumidifier than replace all your stuff!

no the cold isn’t an issue at all, by fan do you mean a normal bladed fan or is there something actually more specialist?

 

[knighty]

any fan will do... just get a normal low power desk fan

anything to get a bit or airflow :-)

 

[123hotchef]

mine was full again today that is about 5-7L a day i think

 

[gaz1]

My garage workshop (now a home gym/workshop) suffers from condensation in the winter where things like metal weight plates are visibly wet.

My garage something like 16 x 12ft with 2 of the walls actually being retaining walls as it’s cut into a hillside. The rear wall is visibly damp which presumably stems from water being pushed through from the earth behind. It’s not too bad just in a couple of places you can see where it eventually runs down the wall where it looks like whatever it was tanked with has failed in a couple of small places. I don’t feel this is a real drama though.

The roof is GRP sat on OSB with no insulation, and actually due to headroom constraints I don’t really want to insulate even between the joists as there’s literally just a few cm clearance for various overhead gym movements as it is!

there’s no real ventilation to speak of. Do you think adding a vent of some sort would significantly improve things or would I just be p*ssing into the wind?

can add some pics in the morning if it seems unclear!

i can say built into the side of a hillside expect damp no amount of tanking will stop it as it will move a little sorry it has to do with earthquakes the tanking will crack or break a seal simple as

on top of that you changed some of its usage to something else whilst it was a garage it was fine

as goes for not insulating it then why are you moaning about the damp then

simple its expected when you wont do anything about it or complain about wont have enough room

the altenative is build above you roof and create a new insulated roof instead

so pick your costs on what you want to use and install

as goes for wall tanking to a degree will stop it but in long run you maybe better making an internal wall and let it breath and insulate the internal wall

 

[123hotchef]

The back of my unit