Mattress Moisture Problem?

[palmer51]

The bottom of our mattress is collecting a lot of moisture on the portion of it that is adjacent to the outside cargo compartment and has developed mold and mildew as a result. Airstream replaced the ply-wood and is shipping us a new mattress. They thought the moisture issue was due to a window leak which they repaired. But now, six weeks later, the mattress is still getting soaking wet. We have had no rain, so it appears to be a condensation problem. On cold evenings the mattress over the cargo compartment gets extremely cold. When we sleep in the bed, we warm the mattress with body heat and the next morning the ply-wood is wet and the mattress is dripping water. Lately, we have started turning on the cargo compartment light in an effort to add a little heat to the area and maybe help correct the temperature differential. This morning we checked under the mattress and it is dripping with water, again! We have tried to protect the plywood with plastic bags. We also have a mattress topper and pad on the mattress. We have dried out the mattress twice and regularly leave the mattress raised up to allow for air circulation. We regularly check the humidity gauge to insure that the humidity stays below 65% by using the heat pump. What could be causing the mattress to collect so much water? Does anyone else have this problem?

[kevin242]

If you have access to a dehumidifyer, you could put that on the floor during times you are not staying in it and see if it removes enough moisture from the air to prevent condensation.

You could also line the cargo compartment with styrofoam to insulate it better. This might prevent the condensation on the cooler surface.

Good luck!

[Ridgerunner3]

I have had this problem in a different brand trailer. I need to start checking under the mattress of our AS. I improved the problem in our old trailer by placing a layer of reflectix insulation under the mattress. Reflectix comes in a roll from Home Depot or Lowes. It looks like shiny bubble wrap. Other types of insulation may work.... for example a sheet of styrofoam siding.

How it works is that the reflectix keeps the warm mattress from contacting the cool plywood surface.

Another thing we found in the past that helped was to take steps to reduce humidity inside the camper. For example: use range exhaust hood while cooking, use bathroom exhaust fan when showering, keep a couple of windows cracked to allow circulation (of course this won't work if the outside humidity is high).

This condensate was most common for us when the humidity inside the camper is high and the outside air is cooler than the inside temperature. Cooler outside temperatures made the problem worse. There were times when we needed to flip the mattress everyday when we got up so that it could dry during the day.

Are there any open seams in the plywood deck of your bed that maybe allowing cool air to contact your mattress? You may want to see if there are any steps you can take to reduce outside air in leakage into the compartment under the bed. Is there any way you could open the compartment under the bed to the inside of the AS to allow the temperature and humidity to equalize with the inside of the camper.

Good luck.

[perryg114]

You could ventilate the area under the bed so it would dry it out. Insulation is always good as well. Anytime you have one surface cooler than another you are going to have condensation. You could put in a 12V computer fan to circulate air between the compartment under the bed and the rest of the trailer. The reflective material under the bed can't hurt.

Perry

[ventport]

I would get a piece of 1" pink or blue styrofoam the size of the plywood, and put that between the mattress and the plywood. That should insulate the mattress from the cold. You could also try to circulate warm air into the cargo compartment with a computer fan. They use very little power and are very quiet. Let us know if you find a solution that solves the problem.

[Silver Goose]

Originally Posted by palmer51

The bottom of our mattress is collecting a lot of moisture on the portion of it that is adjacent to the outside cargo compartment and has developed mold and mildew as a result. Airstream replaced the ply-wood and is shipping us a new mattress. They thought the moisture issue was due to a window leak which they repaired....

Have you ruled out condensation on the inside of the window running down the wall and onto the platform?
65% humidity seems pretty high to me. I would try leaving the roof vents open 24X7 to see for a week or so to see if that helps reduce overall indoor humidity. People, showers and cooking are the primary sources for added humidity in a closed space. Ventilation is effective in disbursing excess humidity to the outside.

If your humidity is 60% at 68 degrees, its dew point is only 54 degrees. If you can get the humidity down to 40% at 68 degrees, the dew point will drop to 41 degrees.

The A/C is an effective dehumidifier, but in heat pump mode the interior air is simply circulated through the heated coils and it neither adds or removes moisture.

As others have suggested, equalizing the temperature of the outside compartment with the room will also be helpful. Efforts to substantially reduce the humidity level inside may be your best bet.

[MStewart]

Is the water/moisture just on one side, or worse on one side? Asking because on our new AS had the same problem, but on one side. Closer inspection of the window, from the outside and along the window rim with the window open, showed two small holes. Will get it replaced but with clear silicone and a Qtip, plugged the holes and the problem has stopped.

Hope your problem is just as easily solved.

[dkottum]

If you are certain there are no leaks, and that can be hard to determine, then there is too much humidity in the trailer at night. Open all the vents at least a bit, wipe out the shower when done, put the wet towels outside at night, whatever it takes to get the inside air moisture down.

doug k

[palmer51]

Update, 11/2/2011, we set the mattress on its side between the shower and head and turned the heat-pump up to 75 degrees, left the cargo compartment light on and lifted the ply-wood hinged mattress platform and left for the day for downtown Atlanta. When we returned the mattress seemed dry and the humidity in the trailer was reading 45%. We made the bed and turned the furnace on and turned in for the evening. This morning the temperature in the AS was 60 degrees with 45% humidity with the outside temperature 35 degrees. Once again the mattress was soaking wet in the area of the hinged plywood deck opening over the cargo compartment. We are thinking that the idea of styrofoam and reflectix is a good start that we can do today. We will keep you posted.

[perryg114]

I think you have a leak. That seems like way too much water. If the humidity was higher I could see this happening but its is not that high. Is this rear bath or center bath?

Perry

[silversled]

It is good to hear that Airstream is helping you. Comforting. I used to help people with water intrusion problems in homes and I offer the following to try to help. Based on your description, I suggest this: there may still be a leak in another area (keep looking – just because you found one doesn’t mean there aren’t more!) and the old leak may have left a reservoir of water somewhere in or near that storage locker. This reservoir may be maintaining this high humidity in this lower locker. Perhaps you have a collection of water under this locker. This may be why your problem persists even when it doesn't rain. Your humidity is too high by indoor air quality standards.

You may want to invest in a moisture meter with a probe (may be able to rent them?). You can place the probe in/on different materials in the trailer that appear "uneffected" (what would be considered normal= baseline) and compare it to your "effected" area. This may lead you to the problem (or a wild goose chase). Have you (or can you) look under the storage locker? Is water accumulating under the floor of the locker from somewhere?

As already mentioned, the temperature differentials are driving the condensation in “one area” but the water source is driving the whole issue. As many can attest, in an Airstream, the water may be appearing in one area but the source may be in an entirely different location. Who knows, you may have an internal water leak.... Sorry to suggest it. Anything is possible.

Good luck and keep hunting.

[Steve & Susan]

I stop drinking everything (water, coffee, beer, etc.) at 5:00 p.m. and have had no wet areas on the mattress (Sorry, the door was open and I just HAD to go through it!)

[CanoeStream]

Interesting... palmer51, thanks for posting about this. I've wondered a few times whether I was observing the same thing. My FB twin bed model has 3 different outside storage compartments under both beds -- a lot of 'cool' operating there.

[r carl]

I think I would heat the compartment with an electric heater and see if it continues.

[dwightdi]

At one time there were 12 volt electric heating elements that you could put under the mattress but I am not sure they are still available or how fast they ran down your battery.

[DaveFL]

My bathroom mirror was showing a lot of condensation last winter, put two dehumidifiers(heater with equivalent of a couple 100 watt lightbulbs) used a timer had them come on at 6am and off by 10 and condensate stopped.
Since them I have found a loose connection behind toilet, supply line tightened so I will wait for winter to see if condensate forms before turning on dehumidifiers.

You do turn off water supply when storing. My tank is under the bed so emptying it would stop a lot of condensate.

[Foiled Again]

May I humbly suggest a test with gift wrap tissue paper. Stuff it around the inside of the access door, and stuff it around the bed platform where it meets the wall - top and bottom. Go away. Come back in 30 minutes and inspect. If you find any that is sodden, you've found the reservoir from the leak. Believe me, a bad leak can FILL the insulation between two ribs with water. It drains out at the nearest convenient opening - like a screw hole for the bed platform.


I just had floor damage repaired that arose from leaks - I'd caught a few here and there - but there were more that I didn't know about.

• What can leak on a 5 year old airstream?
• Everything.
• Why can't I easily locate leaks?
• They Travel - sideways sometimes, down eventually.

At least you have an International which doesn't have mouse fur or vinyl hiding the leak.

It's a real pity Airstream doesn't have an edging for the floor that not only aligns and trims the inside layer of aluminum, but also protects the plywood and creates weep holes on the OUTSIDE for moisture that penetrates EITHER layer of aluminum. Of course what would make that expensive is radiusing it for the corners.


I recommend you also check your access door's gasket. If it's misaligned or partially missing condensation from the outside could run down the side of your Airstream and straght into the storage compartment. The wet tissue test may take all night there. Tightening up the lock, replacing or doubling the gasket is an easy fix. The access door is only about 1 inch thick, and I've never taken it apart to see if there's any insulation in the door itself. Why not insulate BEHIND the access door? A sheet of styrofoam that could be crammed between the floor and bottom of the bed platform from under the bed could reduce heat loss under the bed. Just make sure the light isn't covered.

Paula

[edglenn]

Well, if it's temperature and moisture causing it, you could try sleeping in seperate beds!
Just kidding!
Actually, I had this same problem in a cab-over camper. The area under the mattress was cold enough to cause condensation from our body heat.
The answer (which worked), was putting foil-lined closed-cell insulation on the plywood to reflect as much heat as possible, and provide added insulation. Then I built a frame to keep the mattress OFF the surface. Much like a pallet, with a lot of narrow strips. I used 2x3's for the cross members.
This allowed constant air circulation between the plywood and mattress.
We still had condensation on the aluminum window frames, but the bed stayed dry.
Hope that helps!

[palmer51]

Update, 12/3/11: When we got up yesterday, both the underside of the mattress and plywood platform were dripping wet. So, we leaned the mattress upright between the shower and the head and directed two fans towards the plywood to dry it out. We opened windows in the bedroom and turned on the forward Fantastic Fan. At noon, the interior temp was 70 degrees w/ 47% humidity.

We went to Lowe's to check out available insulation materials. We considered the Reflectix product. The ease of installation was very applealing. Our concern was that the R factor was a bit low and that the bubble wrap might deteriorate over time with the weight of the mattress and our bodies. We decided that the 3/4" reflective foil-backed styrofoam insulation with a 2.9 R factor would be a good option. We purchased two 4 by 8 pieces, a roll of reflective foil tape, a roll of double sided duct tape, a utility knife, and a straight edge. Total cost of construction materials was around $30.

We constructed two pieces of the insulation to fit the plywood platform, butting constructed edges together whenever possible for a tighter, more uniform fit, and sealing all seams with the foil tape. Then, we placed the two finished pieces, one on top of the other, styrofoam facing in w/ reflective foil facing out using the double-sided duct tape for adhesion. The final step was to cover all outside edges with the foil tape.

The finished piece is 1 1/2" thick w/ a 5.8 R rating.

When we retired for the evening, at around 10 pm, the mattress felt comfortable to the touch. In the past, it has been as cold as an icicle, so cold in fact that primal screams ususally accompany our dive in between the sheets. The interior temp was 60 degrees w/ 40% humidity and an exterior temp of 47 degrees.

At 4 am, we woke up all toasty and warm and ever so curious to find out if the project had been successful. The interior temp was 60 degrees w/ 50% humidity and an exterior temp of 37 degrees. When we checked between the mattress and insulation, it was warm and dry. When we checked between the insulation and the plywood platform, it was cold and dry. The word for the day: DRY!

It appears that the extremes in temperature differentials have been causing condensatioin to form.

Footnote: We were unaware of a problem until about two months ago, when we decided to flip the mattress over. It was then that we discovered that the underside felt damp. We took it outside and dried it out in the sun.

When we visited the Airstream Factory in Jackson Center, in late October, they determined that a leak around the back window over the bed might be the culprit. A few days after the repair, we checked under the mattress and it was soaking wet again, and mildew and mold had begun to grow on the mattress and the plywood. We discussed the possibility of an insulation/condensation issue with them at that time.

Airstream replaced the plywood and is shipping us a new mattress for pickup in a couple of weeks in Florida. In the meantime, we removed the moldy mattress underside fabric and discarded it. We appreciate Airstream's willingness to replace the damaged plywood and mattress, but are confused and disappointed about their reluctance to address the condensation issue since we feel that this is a design problem that Airstream should address.

The input and suggestions offered by all of you here on this post are sincerely appreciated! We have spent untold hours researching and agonizing over this issue. On numerous occasions, we have torn up the bed, dragged the mattress outside or set up a heater near it, wiped everything down for possible mold, washed everthing in hot water and bleach, etcetera, etcetera. Now, we have piece of mind that this serious problem has been resolved. Thanks again for your helpful ideas!

[Ridgerunner3]

It is great news that you were able to solve this with insulation under the mattress. As I posted earlier, we had a similar problem in our old SOB. I need to start checking under the AS mattress to see if this condensation issue has followed us to the AS.