I have run into an issue with my new place and was curious if anyone else ran into this issue before.
A couple months ago, my family and I moved into a trailer (rental) - although its not a full blooded "home" - we rather enjoy the home and the lot we are on. But there is one problem. Condensation. Mainly in closets, and areas close to the floor and against the walls.
The trailer was built in 1974 so we are sure it is not insulated properly.
I've had to throw away a lot of things because of mold! Bright white mold! I'm terrified of my kids possibly getting sick from the mold. And I am frustrated that I can't seem to have anything in the house touching the wall without it getting wet and possibly moldy.
We plan on plasticing the windows - but will that really help?
The tighter you seal the place, the more moisture it will hold inside. The more moisture inside when you have cold outside the worse the problem will be. I experienced it years ago in a couple of uninsulated or poorly insulated houses which had poor air circulation a couple of times, but as I remember it was a black mold.
Unfortunately I don't know what you can do about it other than better air circulation and keeping the indoor humidity as low as you can. If you're renting I'd talk to the owner because mold can ruin a place.
Thanks to Marc for your informative Post and/or Attachment!
Get yourself a humidity indicator. I have several around my house, but I'm an air and weather "nut". Actually what I have are combination temperature-humidity gages. Most have barometer readings, too.
But my main point is to get hold of information about what is happening in the house. Before I insulated this place there were some places, especially corners (near the ceiling) of a few rooms which are at the corners of the house, which were slight problem areas. They used to sweat at times when the humidity got too high in here. I can't remember if it was mold or mildew but it was blackish in color. I used a mold & mildew remover to clean the areas up.
That said, the last time I lived in a mobile home was about 1969 or 1970 when I stayed in one for a while in Lexington, KY. I remember it was expensive to heat, but was drafty enough (I guess) and I lived alone so I wasn't putting too much humidity in the air during the winter, that I don't remember condensation problems except on the windows from time to time.
One thing I do know is that air movement is important. I doubt that plasticing the windows will help. That's more of a temperature thing. It might hurt, humidity wise, more than help.
You might want to consider a dehumidifier, but again - I'd get a temp-humidity gage to see what is happening in the place.
I mentioned talking to the owner (assuming you're renting). Mold is very damaging. The last thing you need is to end up with a bill for damage from the person that owns the place. And the owner may be able to give you some tips on how to prevent moisture buildup in winter months.
The outside-to-inside temperature differential creates a temperature gradient across whatever insulation exists at a given location. Even when the inside humidity is fairly high, normally the inside faces of the dwelling are close in temperature to the inside air temp, which means that those surfaces are above the "dew point", i.e. the temperature at which moisture will condense.
If however you put insulative materials--clothes or other household items--against a not-very-well-insulated wall, those materials act as additional insulation. Now the total temperature gradient will be across the combined insulation system, i.e. the actual wall plus your stored materials.
The same thing can happen when the construction of the dwelling provides no heat source within a storage volume such as a closet. The air temperature in that space can decrease substantially. The closet walls and door plus the absence of a heat source have the same effect as if insulation had been placed against the outside wall.
Because the total temperature gradient is across a greater thickness of insulation, the temperature at the actual inside wall face now will be colder. But, the wall face is where the dwelling's vapor barrier is located.
If the insulative material you've added has no vapor barrier, as obviously is the case with clothes, bedding, etc., then water vapor will permeate through that fibrous material until it gets to the vapor barrier at the wall face. But, that wall face now is at a lower temperature...which very easily can be below the "dew point" for the inside humidity level. So water will condense.
Fungus...mold and mildew...is always present in the environment, and will grow wherever it is undisturbed by cleaning and has a water source.
The dew point of course is proportional to the inside temperature and the inside humidity.
Fixes...not all of which are practical:
1. Raise the inside temperature (expensive) and/or get a dehumidifier and lower the inside humidity (also potentially expensive). Neither will be very effective without other steps being taken.
2. Leave the doors open to any storage volumes so that heated air can get into them readily. Store objects and materials so that air can circulate as freely as possible between those objects and the outer wall.
3. Add insulation. If it's added on the inside of the dwelling, make sure that it's fire-resistant, and make sure that the new inner face includes an airtight vapor barrier.
If you can't add insulation everywhere, consider just adding it on the inner or outer faces of the storage volumes.
Assuming there are no air leaks in the walls/ceiling/floor, a dwelling's windows are the greatest heating-energy loss. Adding plastic film over windows will not improve their insulation very much, though if they are even slightly leaky it still can help with heating costs. Note however that decreasing air leaks will increase the inside humidity, as will decreasing condensation on windows.
I have experienced the same problem.
Our 1972 Landola was converted into a house, but when I was doing remodeling I noticed that the inside of the walls was very wet, I thought there was a leak. But after removing the wallboard, I found that condensation would form on the inside of the metal skin, and the insulation would trap it there, keeping it from evaporating. In the winter the inside skin was entirely frosted over, and the insulation was frozen solid. HUD regulations took over in 1978, so prior to that most were just a metal skin with 2x4 or 2x3 studs and 3 1/2" of insulation. Because of the temperature swings, this just becomes a water pump.
The cure would not be possible in your situation, but what I did was remove the walls, and line the inside of the metal with plastic sheet, then replace the insulation, then line that with plastic sheet, then replace the wallboard. This did not increase the humidity as some people expected since the ceilings were left as is, and that vented enough moisture. By reducing the contact air on the inside of the walls, the whole room dried out well, and no problems since.