Moisture & mildew issues?

Question

Hey Everyone,We have our 5er on our lot on the Western slopes of the Cascades in Washington. We have spent a month or two at a time over here in the past but this is our first full winter in the rig.FYI: the trailer is parked under a full roof/cover that keeps the rain off.We have always kept a dehumidifier running and not had any significant issues. Well recently we started smelling a bit of a musty smell. Then serious moisture issues on the bedroom windows and in the bedroom closet. Then the dehumidifier died...I replaced the dehumidifier with an identical unit. Things are better but have not returned to the comfort level we enjoyed previously.Last night it was about 50F in the bedroom. The dehumidifier was running as well as a fan. It was still too muggy to sleep.This morning my Wife lifted the mattress up to put on fresh sheets and found significant mildew spots on the underside of the mattress...YUK!!!!!!!!!!!!!I need to figure out how to get this under control and how to clean/treat the spots already on the mattress.I do understand that the moisture issue occurs when the warm moist air inside comes in contact with a cooler exterior surface and the moisture condenses out.To address the mattress (after I figure out how to clean it properly) I had considered elevating it on something resembling a shipping pallet. This would allow airflow between the mattress and base. Another idea I had was to place a sheet of foam insulation board between the mattress and base to provide a "thermal break" and avoid condensation on the mattress.I don't know if either of these ideas will be effective. I am hoping that someone out there has experienced this and can  share their solution:How do I clean the mildew spots?How do I prevent future problems?Thanks in advance.Steve

dutchmensport · Answer

To clean the mildew, a bathroom mildew cleaner may help, depending on the surface, bleach water.

Yours is not the first thread about excessive moisture in an RV in the Pacific NW area. The weather there must be horrid this year. A few have posted about this problem recently.

Considering you are actually in the camper, have electricity, and actually using it, the option would be a second dehumidifier. Air flow is important, but if you crack a vent or window, your letting as much humidity IN as you are OUT. Heat will dry out the existing wetness on the walls and such, but the heat can also cause more condensations to.

I think your best option is a second dehumidifier and hope for an early dry Spring .... After all ... that darn groundhog in Pennsylvania did say it would be an early spring!

tonymull · Answer

Ventilation and heat.  We keep a space heater set to 50 degrees in the truck camper, no problems.  And we keep the furnace set to 50 degrees in our park model.  The furnace air exchanger works for ventilation.  In our travel trailer we kept a space heater set to 50 degrees and a couple of windows open. Those are storage options.  When you are there you, by breathing and cooking are pumping more moisture into the air than when it's empty. You'll have to allow for that.  Maintaining a consistent temperature will help some.  We are near Lake Stevens and humidity has never been a problem with those things in place, never needed a dehumidifier.  This has been a warm, wet winter, not a good combination and that could be part of your problem.

rekoj71 · Answer

Yep, It's a problem for anyone who resides in their RV in cold country. Are your windows dual pained? if not you might consider using that film that sticks to the inside edge then gets stretched tight with a hair dryer, I saw it at home depot and a neighbor of our used it on his single pane windows in his RV and it helped a bunch. I mostly have the problem on the single pained windshield and keep a washcloth handy to wipe it down regularly and wring it down the sink. A second dehumidifier might help but remember they work best when the air inside is rather warm so that their cooling fins can attract the moisture.
The moisture in the bed is probably coming from a window above and then rolling down the wall and into the bed. I have noticed on ours a couple of times when it was extreamly cold out and so humid inside that I could find all of the aluminum studs in the walls as they too were sweating.
As far as ventilation goes, if the cold air outside measures the same percentage of humidity as the inside warm air, remember that that is still less overall humidity cause the colder air can't carry the same amount of actual water vapor.
We make sure we use a power vent whenever we shower or cook, even if it's cold out. Thankfully our electric is included and our space heaters can more than make up for it without costing us.
My only idea that might work better than the pallet if you want to raise the bed for ventilation would be to possibly use a more plastic material that won't absorb moisture, like maybe PVC pipes.

Good luck.

coolmom42 · Answer

Hypervent is what you need under your mattress.Otherwise, keep the temperature up to about 60 minimum, and run the dehumidifier all the time.  You may need an additional dehumidifier.

pnw_steve · Answer

rekoj71 wrote:Yep, It's a problem for anyone who resides in their RV in cold country. Are your windows dual pained? if not you might consider using that film that sticks to the inside edge then gets stretched tight with a hair dryer, I saw it at home depot and a neighbor of our used it on his single pane windows in his RV and it helped a bunch. I mostly have the problem on the single pained windshield and keep a washcloth handy to wipe it down regularly and wring it down the sink. A second dehumidifier might help but remember they work best when the air inside is rather warm so that their cooling fins can attract the moisture.The moisture in the bed is probably coming from a window above and then rolling down the wall and into the bed. I have noticed on ours a couple of times when it was extreamly cold out and so humid inside that I could find all of the aluminum studs in the walls as they too were sweating.As far as ventilation goes, if the cold air outside measures the same percentage of humidity as the inside warm air, remember that that is still less overall humidity cause the colder air can't carry the same amount of actual water vapor.We make sure we use a power vent whenever we shower or cook, even if it's cold out. Thankfully our electric is included and our space heaters can more than make up for it without costing us. My only idea that might work better than the pallet if you want to raise the bed for ventilation would be to possibly use a more plastic material that won't absorb moisture, like maybe PVC pipes. Good luck.Thanks for all of the replies.I have single pane windows and have looked at the "shrink wrap" option. I could not find a reasonable attach point for the shrink wrap. I have been tinkering with a solution.As to the source of the moisture: I think that a good portion of it comes from the moisture that we exhale &amp; perspire in the night. I did find some details regarding the mattress on the manufacturers website. It claimed that the mattress must be on a support that provides airflow under the mattress because we sweat up to a pint during the night. That moisture can soak all of the way through the mattress and must have airflow to evaporate. The offered a platform that looks very much like a pallet.I find the idea that I sweat enough to soak all of the way through an 8" mattress disgusting but when I look at the pattern of the mildew stains on the bottom of the mattress I have trouble arguing the point.Sooo..... Home Depot, 3-2x4's, 14- 1x2's and a handful of screws. Now we have airflow under the mattress.While I was there I found a product called Concrobium. It has good reviews online and claims to kill and prevent future growth of mold/mildew. So I treated the mattress and surrounding surfaces.

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Moisture & mildew issues?

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