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Storage room condensation

NeXT

NeXT

Veteran Member
Joined
Oct 22, 2008
Messages
8,149
Location
Kamloops, BC, Canada
I'm running into a serious problem with my primary storage area for my spare computers and parts.
My workship is originally a deck that was expanded off the kitchen and then windowed up and sealed with foam. The floors, ceiling and the walls are all uninsulated but the room is otherwise sealed from the outside. I have a crawlspace that is triangular in shape with a black shingle roof on it and a bit less sealed up (hornets nests are present but I don't see any sizeable holes or gaps) that I can block off using a wooden door.
Now that it is fall I am noticing that I'm getting condensation forming on any CRT monitor faces and anything immediately facing the front of the CRT.
My assumption is that the moisture comes from the kitchen (because when someone cooks rice or something, all the windows in the house fog up) so I close the doors between there and the shop but it's still happening and I can't keep packing things into the crawlspace until I'm sure I can come back to it a few month to a year later and not find ruined electronics. Should I be doing something like putting sheets or old clotes over the monitors to capture some of the moisture?
 
What is really needed is a small but steady stream of fresh air, good insulation and just a little heat to keep it a few degrees above ambient. Could the exterior wall area be overboarded with e.g. Celotex then gyproc? Similar for the floor, if there is enough height then celotex under partical board boards wonders.

Another alternative might be to seal it tight then install a dehumidifier with a plumbed waste?
 
NeXT said:
... My assumption is that the moisture comes from the kitchen (because when someone cooks rice or something, all the windows in the house fog up) so I close the doors between there and the shop but it's still happening and I can't keep packing things into the crawlspace until I'm sure I can come back to it a few month to a year later and not find ruined electronics. Should I be doing something like putting sheets or old clotes over the monitors to capture some of the moisture?
Click to expand...

I think sheets will help in that situation. However, I've been in houses like that (lived in Vancouver for 45 years) and I think the better solution is to deal with the whole house. Obviously something is creating enough humidity to bring it to condensing. Either turn up the heat (bad idea) or get a kitchen exhaust fan. (good idea) BTW, cooking rice in a pot with lots of steaming is also bad practice. Turn it way down or get a rice cooker. (personal opinion)

I've also seen excess condensation from un-vented gas burners for both heating and cooking.
 
I'm paying rent on the house. there's no way I can afford to insulate the house. Roommate has an entire cupboard crammed full of Wal-Mart brand seasoned rise. He lives off the stuff and it shows in his weight so there's always some cooking on the stove. I don't think I could get him to buy a rice cooker.
 
..the irony being rice itself absorbs moisture so maybe start storing his rice in the storage room with your equipment lol
 
So today I put a fan in the crawlspace to air it out and went out for the afternoon and bought a rice cooker.
I also stuffed foam into an open gap around the crawlspace door.
 
1- You should have continuous ventilation inside the house; so
if you can install one or more fans at different locations, installed
on the window or an appropriate place, to push the air out of the
house, it would reduce the relative humidity to that of the outside.

2- Try installing a hood over the stove or any cooking area with a
venting duct towards the outside.

ziloo
 
My father used to keep his small 'mobile home' in storage in an old barn over the winter. inside it (the caravan section) he would leave a box that he had bought somewhere, it was some kind of purely mechanical de-humidifier - I never took a close look. When spring time arrived it was full to the rim with water.

I have no idea how efficient those things are. The caravan didn't feel damp inside at least. But if that would be sufficient to de-humidify a room like the one described by the OP.. maybe not. Or maybe with four or five of those..

-Tor
 
#%*$.

After assuming I had finished patching the crawlspace and knew that for a week at least it was fine I left it alone for the winter.
I open the door this morning to get at a monitor and it REEKS of mildew. Pull out a bin of cables and there's mold growing on it.
I relocated some of the gear and stuffed two fans back in the crawlspace again. Everything I pulled out also showed signs of growth yet I found no signs of leaks.
This is getting really annoying now. I'll have to completely empty out the crawlspace when things warm up and look at my options from there.
 
I have an unheated woodshop in my basement in a space that was supposed to be a crawl space. Someone shot the elevations wrong and the "crawlspace" wound up to have 12' ceilings, so we put some (double-glazed) windows in--but there's no slab floor, just a layer of rock and gravel on top of dirt.

I put some 10 mil poly sheet over the rock and built a raised floor using PT 2x6" T&G anchored to the stem walls. Over that, I laid two layers of roofing felt and then some 3/4" plywood, followed by vinyl tile. The walls are insulated to R-40 and sheetrocked and the ceiling is done similarly--under the sheetrock is a layer of 5 mil poly.

The space is unheated (I have a space heater for when I'm using the shop) but there are no moisture problems at all. I take away the following from this:

Insulation is important, as are vapor barriers--and the last is very important. Your walls may be wood, but wood breathes and moisture will get in. Masonry likewise exudes moisture.

If you haven't, use some heavy poly sheet and a stapler and make a real barrier on the walls, floor and ceiling. The dead air between the sheet and wall will also act as insulation. You can use roofing felt on the floor, taping the seams with duct tape if the area gets traffic.

That should improve things for not a lot of money.
 
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NeXT said:
#%*$.

After assuming I had finished patching the crawlspace and knew that for a week at least it was fine I left it alone for the winter.
I open the door this morning to get at a monitor and it REEKS of mildew. Pull out a bin of cables and there's mold growing on it.
Click to expand...

Mildew and mould have got to be from a lack of circulation. These organisms need stale air to survive. In my many years in Vancouver I've lived in a leaky old wooden house and have had all my stuff be as dry as can be. That's in a house without a bathroom vent fan. I really think you have some serious problem that is specific to your house. You shouldn't have to do anything to a crawl space in a Vancouver house other than keep the rain from coming in. I've even had stuff under the porch outside for years on end and it's never gone mouldy or had mildew.

Really, I think you need to check that the furnace is operating properly. That is a common source of moisture in a house. Look at the furnace flue and make sure it is connected properly, especially near the top where it might just have been shoved in place by a careless roofer. Oh, and do the bathroom and kitchen fans vent to the outside, or just into the attic. :) Your attic needs to have vents to the outside, perhaps your house has a basic construction flaw. You might want to Google how that is supposed to be unless you want to talk to the building inspector. (probably not!) Quoted from a web page on the subject: "The first stage in effective ventilation is getting the hot air out. That's what exhaust vents do." Are you mistakenly doing the opposite? I have a feeling you are.

Remember that hot air can hold a lot of moisture and cold air can hold very little. Here are some other ideas. Is there a clothes dryer with a broken vent? Is there a gas fireplace with improper venting to the outside. Do you have a gas stove that people leave on for heat?

Edit: Here is a random page on the subject: http://inspectapedia.com/interiors/atticcond7.htm
 
NeXT: having lived in Vancouver/the lower mainland/Victoria for 30 years, there's really only one answer to avoid your humidity problem.
Do what I did, and move to Arizona.
You'll never get away from humidity in Vancouver - even if you stop the condensation, the humidity is still too high to store old computers properly.

PS: condensation will be caused by too much humidity inside a space hitting a cold surface (ie: window in the winter) but will only condense if there is poor ventilation. That's why they put the floor registers under the windows - blow warm air up and over the glazing to offset the heat loss through the window, and stop the condensation.
 
Furnace does not reack my workshop or the crawlspace. Got rather cold in here over the winter.
Actually, the dryer vent is in the car park below. I guss that will explain a bit of the humidity. I guess all I can really do is install vents on either end of the crawlspace with screens to keep the hornets out.
Stil, this sucks.

If you haven't, use some heavy poly sheet and a stapler and make a real barrier on the walls, floor and ceiling. The dead air between the sheet and wall will also act as insulation. You can use roofing felt on the floor, taping the seams with duct tape if the area gets traffic.
Click to expand...
Wouldn't the dead zone between the wall/ceiling and the plastic also lock in moisture and cause mold?
 
NeXT said:
Wouldn't the dead zone between the wall/ceiling and the plastic also lock in moisture and cause mold?
Click to expand...

Eh, without insulation you probably have mold on the interior sheathing anyway, as you don't seem to have much air circulation. People generate moisture just by living and that will condense on the sheathing. You could leave a gap of a couple of inches on the wall membrane at the top and bottom to encourage air circulation, but I don't know how much good it will do. A vapor barrier on the floor might help some.
 
if ur sealing it up then ur guna get the mold issues speacialy if theres moisture coming up out of the ground so keep it ventalated well and u may wana lay a vaypour barior down and aww if u got mold issues that bad i would look at fumigating the crawl space as ur structures going to be just coverd in mold if u got it that bad on computer parts..........
 
1ajs said:
if ur sealing it up then ur guna get the mold issues speacialy if theres moisture coming up out of the ground so keep it ventalated well and u may wana lay a vaypour barior down and aww if u got mold issues that bad i would look at fumigating the crawl space as ur structures going to be just coverd in mold if u got it that bad on computer parts..........
Click to expand...

Must have been posted from an iPhone. :shrug:

Yes, the vapor barrier over any bare ground is a absolute necessity.
 
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