Dealing with moisture in garage, mad idea?

Rorschach · Post by **Rorschach** » Wed Jul 08, 2020 7:30 am

As long time listeners will know last year I purchased a garage in a block to use for storage. It's single skin brick and two walls are mostly buried. I get some moisture coming through the back wall, it's nothing excessive, it's not running with water but the wall is always damp. I am a bit worried about items getting mouldy from stagnant wet air in there. So I was thinking about ways to improve air circulation.
I don't think adding vents would be possible or even that helpful as there are gaps around the door etc anyway and the roof space is open to all the garages in the block so it's more about moving the air around inside.
My initial thought had been maybe a fan running from a solar panel, anyone have experience doing something like this?

Someone-Else · Post by **Someone-Else** » Wed Jul 08, 2020 10:58 am

It will not work at night, and motors have a high starting current, which means you will need a bigger than you think solar panel.
If you have some cash to waste, you might want to try several computer case fans mounted on a board, mounted behind a vent, and make sure they are pointing the right way.

A fan sitting in the middle of the room is only going to circulate air, not remove it.

Rorschach · Post by **Rorschach** » Wed Jul 08, 2020 11:02 am

Working during the day would be be fine, if the solar panel could produce more than the fan consumes I could add a battery in there maybe. Not worried about removing air as such, the gaps will do that, more just moving the air around so that there aren't any dead spots.

Someone-Else · Post by **Someone-Else** » Wed Jul 08, 2020 11:27 am

"Adding a battery" sounds easy, good and simple, but it isn't.
What size battery will you add?
What will stop the battery from running flat?
What will stop the battery from over charging?
What is going to charge the battery?

Too many questions too much to not work, too much grief, too much money.

If you really do want to do something, go with my first option, its cheaper and it may work, your idea will be expensive and a waste of time.

First of all you can not add "a battery" first you need a voltage regulator/charge controller, then you need the appropriate size battery, the size of that battery will depend on: A. How much current your fans draw. B. How long you want the fans to run for. Once you have figured that out, you can then figure out how big/many solar panels you need to charge the battery and run the fans. Yes it can be done, but it will not be cheap.

As for fan circulating the air, waste of time.

I have a shower, the room fills with steam, I turn on the extractor fan, I don't turn on a circulating fan. The extractor fan sucks air from the room and takes it outside, same with your situation, circulating the air is no use, it just moves it from one place to another, it does not get rid of it.

I really don't want to rain on your parade, but I would never store anything in a damp room, even with fans, what if one fails, and with solar it will not work at night or bad weather, sell the garage and look for something better. Or grow mushrooms and sell them. (No real edible mushrooms)

Rorschach · Post by **Rorschach** » Wed Jul 08, 2020 1:09 pm

Ok I'll put the garage up for sale this afternoon and then go and sit in the corner and have a good old think about my life.

Someone-Else · Post by **Someone-Else** » Wed Jul 08, 2020 1:27 pm

As you wish.

But if a person posted on here that they are storing stuff in a damp leaking shed and said stuff is mouldy what would your advice be?

big-all · Post by **big-all** » Wed Jul 08, 2020 1:59 pm

my thought
paint a damp proof membrane 1m beyond to the side and below the damp patch and half a meter above
if you have a damp area you need ventilation to remove it otherwise a fan will just average out the damp all over the garage
if you can introduce ventilation above the damp area and a fan drawing air and pushing it towards the vent then hopefully would minimize the damp elsewhere
would also keep a say 150mm gap between the damp wall and stored stuff with floor to vent clear air to allow circulation

Rorschach · Post by **Rorschach** » Wed Jul 08, 2020 3:05 pm

someone-else wrote: ↑Wed Jul 08, 2020 1:27 pm As you wish.

But if a person posted on here that they are storing stuff in a damp leaking shed and said stuff is mouldy what would your advice be?

It isn't leaking and there is no mould as yet, I am looking at a preventative measure.

The garage is part of the block with a shared roof, there is a gap at the roof that runs across all the garages so there is plenty of space for air to move in and out of the block as there are lots of garage doors with gaps around them etc. What I want is make sure that the air in my garage is moving around as much as possible so it mixes with the air in other garages etc.

Someone-Else · Post by **Someone-Else** » Wed Jul 08, 2020 3:30 pm

Still wont work. As big-all said

big-all wrote: ↑Wed Jul 08, 2020 1:59 pm a fan drawing air and pushing it towards the vent then hopefully would minimize the damp elsewhere

Moving it around is not good enough, like an extractor fan in a bathroom does, you need to get the damp air out.

big-all · Post by **big-all** » Wed Jul 08, 2020 8:31 pm

someone-else wrote: ↑Wed Jul 08, 2020 3:30 pm Still wont work. As big-all said
big-all wrote: ↑Wed Jul 08, 2020 1:59 pm a fan drawing air and pushing it towards the vent then hopefully would minimize the damp elsewhere
Moving it around is not good enough, like an extractor fan in a bathroom does, you need to get the damp air out.

quite difficult to know really
the amount off airbound moisture in a cold damp building will be less as the air wont support it it will simply condense on the coldest surface
fans in bathrooms work well because you are drawing warm dryish air from the house into a warm bathroom allowing the moist air to escape without the room cooling

Someone-Else · Post by **Someone-Else** » Wed Jul 08, 2020 8:44 pm

big-all wrote: ↑Wed Jul 08, 2020 8:31 pmfans in bathrooms work well because you are drawing warm dryish air from the house into a warm bathroom allowing the moist air to escape without the room cooling

Might be in your house, certainly not mine and all the others I have seen.

A bathroom extractor works because it is reducing the air pressure in the room and so the steam gets "sucked out" nothing to do with warm air. It was indeed yourself (big-all) who pointed out the obvious on a bathroom extractor fan query some time ago. You said (similar to) "You can have as big an extractor fan as you like, it won't work unless there is air coming in to replace the air you are taking out" In other words, when you have a shower leave the door open so air can come in.

He needs to get the damp air out. Which is why good ventilation is a must.

big-all · Post by **big-all** » Wed Jul 08, 2020 8:48 pm

normally bathroom doors are fitted with a 12mm gap at the bottom to allow air to be drawn from the house

Someone-Else · Post by **Someone-Else** » Thu Jul 09, 2020 4:42 pm

Mine isn't, but it is narrower than the other doors.

It was reading what you mentioned that made me think of putting a vent in the door.

I carried out a simple experiment thanks to you (Couple of years ago)

Filled bathroom with smoke (I have a smoke machine) left door shut turned on fan, smoke took ages to clear. Repeated then opened door a few cm, whoosh most went with in seconds. So obvious after you pointed it out, but not before.

big-all · Post by **big-all** » Thu Jul 09, 2020 5:22 pm

i think the point is we are all------ still learning

often its in our heads often we forget often i talk to my self and still get it wrong

sometimes my brain goes blank and i simply go and do something else until my brain wakes up

life is an experiment where often there is one or a hundred possible solutions where the actual solution will be based on whats in the front off your mind good or bad and often change from day to day

big-all · Post by **big-all** » Thu Jul 09, 2020 6:09 pm

i have just realized what the problem is here

in my mind it fan drawing air from the gappy door through the garage and out the back
in your mind it will just be air swirling around going no where in particular

i think we are all guilty off not listening [fully reading]as much as we should