# Moisture Under The Mattress



## kimbo1020

Welcome suggestions on a problem with moisture(condensation)under mattress - carpet was slightly damp and mattress has foul smell. We have been staying in OB for several monthes while husband is on a project out of town for work. We are wondering if there is some type of barrier that can be purchased to go between the floor and bottom of mattress to allow air flow. We believe this is the problem as we have not found any leaking. We run the fan while showering and cooking with vents wide open. Have not been leaving vents open all the time as we are in a colder area currently - but I see from other comments that keeping open is still advised during colder temps. We will do from now on. If anyone has any other ideas about the mattress problem please advise. Thanks for the help in advance!!!!!!!


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## thefulminator

What kink of trailer and where is the mattress located? Is it in a slide out, bunk bed or a free standing bed platform?


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## kimbo1020

kimbo1020 said:


> Welcome suggestions on a problem with moisture(condensation)under mattress - carpet was slightly damp and mattress has foul smell. We have been staying in OB for several monthes while husband is on a project out of town for work. We are wondering if there is some type of barrier that can be purchased to go between the floor and bottom of mattress to allow air flow. We believe this is the problem as we have not found any leaking. We run the fan while showering and cooking with vents wide open. Have not been leaving vents open all the time as we are in a colder area currently - but I see from other comments that keeping open is still advised during colder temps. We will do from now on. If anyone has any other ideas about the mattress problem please advise. Thanks for the help in advance!!!!!!!


Ob is the 2011 269RB(large rear bathroom unit)with front bedroom - free-standing short queen platform bed not in a slide.


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## CamperAndy

You would be surprised how much moisture you loose while you sleep and gets absorbed in the mattress. Ventilation is key but at this point a new mattress may be in order, if it smells it will be moldy. If you have shore power get a small electric blanket and place it UNDER the mattress to prevent condensation from forming due to moisture migration through the mattress and condensing on the platform. Just set it on low and that should prevent the condition from occuring.


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## thefulminator

Is the storage compartment under the bed cold? Is the platform a sheet of plywood supported by an aluminum frame with no insulation under it? If you feel around the edge of the mattress on the underside, is it wet there but not so wet in the middle? I would bet that the moisture is condensation on top of the platform. I am wondering if you see more condensation where the platform sits on top of the aluminum frame that supports it. That meaning that you have an area that stays cold because it sits on the aluminum frame.

If this is your case, then I think your answer is to put a layer of insulation on top of the platform so the moist air doesn't touch it. Something like sheet foam or Reflectix would probably be your best choice. Reflectix is basically bubble wrap with aluminum foil on both sides. A lot of the people over at popupexplorer.com (tent trailer site) use Reflectix under mattresses on their bunk ends.

A popup trailer with reflectix under the mattress.


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## kimbo1020

CamperAndy said:


> You would be surprised how much moisture you loose while you sleep and gets absorbed in the mattress. Ventilation is key but at this point a new mattress may be in order, if it smells it will be moldy. If you have shore power get a small electric blanket and place it UNDER the mattress to prevent condensation from forming due to moisture migration through the mattress and condensing on the platform. Just set it on low and that should prevent the condition from occuring.


You are right - we were sure NEW mattress was in order - BUT - did not want to damage a new one - looking for cure first!! The electric blanket seems like an easy remedy as long as it is safe - concern about fire hazard there. I read somewhere about barriers such as tyvek, reflectix etc. Still seem to wonder about some way of creating some air-flow under there????? It is right above our pass-thru storage so thinking insulation of some kind inside pass thru may help as well. What about the use of a dehumidifier?


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## kimbo1020

thefulminator said:


> Is the storage compartment under the bed cold? Is the platform a sheet of plywood supported by an aluminum frame with no insulation under it? If you feel around the edge of the mattress on the underside, is it wet there but not so wet in the middle? I would bet that the moisture is condensation on top of the platform. I am wondering if you see more condensation where the platform sits on top of the aluminum frame that supports it. That meaning that you have an area that stays cold because it sits on the aluminum frame.
> 
> If this is your case, then I think your answer is to put a layer of insulation on top of the platform so the moist air doesn't touch it. Something like sheet foam or Reflectix would probably be your best choice. Reflectix is basically bubble wrap with aluminum foil on both sides. A lot of the people over at popupexplorer.com (tent trailer site) use Reflectix under mattresses on their bunk ends.
> 
> A popup trailer with reflectix under the mattress.


It seems the mattress bottom and the platform both feel damp from side all the way to the center. I am wondering if a layer of the reflectix coupled with the heating blanket would be the answer. We are heating with propane which I understand also adds moisture to the air inside. Temps are dipping into the 20's at night and rising to between 45 - 60 in the day. Campground requires extended-stay campers to use propane during winter monthes.


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## CamperAndy

The use of propane in the furnace does not add moisture to the air as it is isolated from inside the trailer, with the combustion happening in the furnace fire box. It does when used for cooking as the combustion is not isolated from the inside of the trailer.

Insulation under the heating blanket will improve the situation.


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## kimbo1020

CamperAndy said:


> The use of propane in the furnace does not add moisture to the air as it is isolated from inside the trailer, with the combustion happening in the furnace fire box. It does when used for cooking as the combustion is not isolated from the inside of the trailer.
> 
> Insulation under the heating blanket will improve the situation.


Thank you - I think we will start there. Just wanted to resolve before plunking down $$$ for a new mattress. Much appreciated - all who chimed in!!!


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## thefulminator

If the plywood is thin and not sealed you may be getting some moisture passing through it. Does the plywood feel damp on the underside?


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## Scoutr2

Just a thought . . .

If you will be camping in cold weather for awhile yet, or maybe in the future, think about perhaps installing some cabinet doors under the foot of your bed platform. You can keep the doors partway open to allow warm air to circulate under the bed platform, which will alleviate the cold space beneath your mattress. That should help stop the condensation in that area. And a bonus to this mod would be the easier access to that storage space beneath your bed! (Or you could cut a hole and install a decorative grill, like on your cold air returns in your home. Just so you get rid of the warm damp air vs. cold space, causing condensation on the warm side.)

Mike


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## kimbo1020

Scoutr2 said:


> Just a thought . . .
> 
> If you will be camping in cold weather for awhile yet, or maybe in the future, think about perhaps installing some cabinet doors under the foot of your bed platform. You can keep the doors partway open to allow warm air to circulate under the bed platform, which will alleviate the cold space beneath your mattress. That should help stop the condensation in that area. And a bonus to this mod would be the easier access to that storage space beneath your bed! (Or you could cut a hole and install a decorative grill, like on your cold air returns in your home. Just so you get rid of the warm damp air vs. cold space, causing condensation on the warm side.)
> 
> Mike
> 
> Thanks Mike - I like both of those ideas!! Cabinet doors or decorative grill. Makes sense!! We are currently in SC and having unseasonably cold weather.


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## kimbo1020

thefulminator said:


> If the plywood is thin and not sealed you may be getting some moisture passing through it. Does the plywood feel damp on the underside?


Just checked for dampness on underside of plywood(part that hinges up for access to storage under bed ~ no moisture and was fairly warm under there as well)- it appears to be damp mostly where mattress sits directly above pass-thru. Hmmm - may have something there!! If that's the case may be back to the insulation solution.


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## CamperAndy

Some have a laundry hatch in the top of the pass through, then you place a basket in the pass thru to just drop your clothes in, you can leave it open at night to help the air circulate. This could be an alternative to the inside access door or vent. So many choices!!


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## thefulminator

Do you have a comforter or blankets that hang over the edge of the platform that would trap air? You might try pulling the edges up on top of the mattress during the day to see if it starts to dry out.


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## kimbo1020

thefulminator said:


> Do you have a comforter or blankets that hang over the edge of the platform that would trap air? You might try pulling the edges up on top of the mattress during the day to see if it starts to dry out.


Yes - we did and my husband thought that could be contributing to the problem - just started flipping it up on sides to see if that helps.....haven't had enough time to know for sure yet!! Man, you guys are thinkers!!!


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## Scoutr2

kimbo1020 said:


> If the plywood is thin and not sealed you may be getting some moisture passing through it. Does the plywood feel damp on the underside?


Just checked for dampness on underside of plywood(part that hinges up for access to storage under bed ~ no moisture and was fairly warm under there as well)- it appears to be damp mostly where mattress sits directly above pass-thru. Hmmm - may have something there!! If that's the case may be back to the insulation solution.
[/quote]

I agree. If the dampness is isolated to only the area above the pass-thru, then you either must somehow heat the pass-thru space (not really a simple, inexpensive, or sensible solution) or insulate the inside against the cold. Insulate that area well and top off with a piece of Tyvek house-wrap, with the printed side down. The Tyvek will prevent any condensation beneath to pass through to the mattress.

Just another thought . . .









Mike


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## thefulminator

If the plywood isn't sealed, you could always give it a coat of exterior polyurethane or varnish to help block moisture. I still think the Reflectix is the way to go. But that is just my opinion.


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## CamperAndy

The moisture is not coming up through the plywood deck but going down through the mattress. Sealing the plywood with sealer or a cover is great for the plywood but does not prevent the condensation on top of the deck getting the mattress soggy and moldy. Needs at least 1" foam insulation, heat between the plywood and the mattress or heat in the pass thru.


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## thefulminator

CamperAndy said:


> The moisture is not coming up through the plywood deck but going down through the mattress. Sealing the plywood with sealer or a cover is great for the plywood but does not prevent the condensation on top of the deck getting the mattress soggy and moldy. Needs at least 1" foam insulation, heat between the plywood and the mattress or heat in the pass thru.


That was my point. If you are going to protect the mattress, then you had better protect the plywood too. That was why I also suggested the Reflectix as used on the tent trailer in my prior post.


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## W.E.BGood

A suggestion for what to do about the smell/possible mold developing in the mattress. Get a quart bottle of isopropyl alcohol and a pump sprayer head that'll screw onto it. Spray all of one side until it's pretty damp with the alcohol, let dry, flip it and repeat. The alcohol is a drying agent, kills the bacteria, and leaves little to no residual odor (although it's quite Frenchie-parfume' smellin' to start with).
Before I retired, I used it everyday at the end of the day in my work boots and the inside of the panels of my body armour (lots of perspiration in both)...came back the next day and they always smelled clean. Regards, BGood


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## kimbo1020

Scoutr2 said:


> If the plywood is thin and not sealed you may be getting some moisture passing through it. Does the plywood feel damp on the underside?


Just checked for dampness on underside of plywood(part that hinges up for access to storage under bed ~ no moisture and was fairly warm under there as well)- it appears to be damp mostly where mattress sits directly above pass-thru. Hmmm - may have something there!! If that's the case may be back to the insulation solution.
[/quote]

I agree. If the dampness is isolated to only the area above the pass-thru, then you either must somehow heat the pass-thru space (not really a simple, inexpensive, or sensible solution) or insulate the inside against the cold. Insulate that area well and top off with a piece of Tyvek house-wrap, with the printed side down. The Tyvek will prevent any condensation beneath to pass through to the mattress.

Just another thought . . .









Mike
[/quote]

Thanks Mike - we are feeling cnfident that the pass-thru temp coming in contact with the warmth of us on our mattress is the root of the problem. My husband has decided to put foam insulation inside pass-thru between alum frame - he will also put reflectix or tyvek inside on top of platform - then he is gonna construct a frame(low profile)for mattress to sit upon that will allow air-flow under it. We also believe keeping comforter on top of mattress hanging down was aiding to the problem - so will either flip up sides or pull back to to expose the area that sits above pass-thru to allow the air-flow.

The current mattress is going immediately and will be purchasing an upgrade







and we will implement the changes to correct the problem. We realize if we weren't in the OB for an extended time this issue may not have ever come up. Other than this issue we have thoroughly enjoyed our time in it!! Thanks to all that have helped us with figuring this out. I will keep you updated on the results - hopefully it will help someone else. Outbackers is a great community of helpful, caring folks!!!!


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## kimbo1020

W.E.BGood said:


> A suggestion for what to do about the smell/possible mold developing in the mattress. Get a quart bottle of isopropyl alcohol and a pump sprayer head that'll screw onto it. Spray all of one side until it's pretty damp with the alcohol, let dry, flip it and repeat. The alcohol is a drying agent, kills the bacteria, and leaves little to no residual odor (although it's quite Frenchie-parfume' smellin' to start with).
> Before I retired, I used it everyday at the end of the day in my work boots and the inside of the panels of my body armour (lots of perspiration in both)...came back the next day and they always smelled clean. Regards, BGood


Thanks for that idea!! We have decided to upgrade mattress - BUT we do still need to deal with the odor in the carpet above the pass-thru that was damp. I have already sprayed a mixture of bleach and water. It did help - but the smell from the bleach was a little overwhelming. If I can find out there wouldn't be a chemical reaction between the bleach I've already put down and the alcohol, I would like to use that. It would be more friendly on the carpet as far as bleaching out the color(didn't do when I used as I diluted enough to not cause). Thank you, Kim


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## Dub

Throw a bag of charcoal in the pass-thru area, it should absorb most of the moisture from the temperature changes. Used to use it in a storage unit all the time to keep my furniture fresh, worked well. If it's not enough try some damp-rid.


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## raynardo

_







....just a thought....._


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## CamperAndy

raynardo said:


> _
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> ....just a thought....._


I don't think that is the issue but if they work for you that is good to know.


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## Jewellfamily

kimbo1020 said:


> A suggestion for what to do about the smell/possible mold developing in the mattress. Get a quart bottle of isopropyl alcohol and a pump sprayer head that'll screw onto it. Spray all of one side until it's pretty damp with the alcohol, let dry, flip it and repeat. The alcohol is a drying agent, kills the bacteria, and leaves little to no residual odor (although it's quite Frenchie-parfume' smellin' to start with).
> Before I retired, I used it everyday at the end of the day in my work boots and the inside of the panels of my body armour (lots of perspiration in both)...came back the next day and they always smelled clean. Regards, BGood


Thanks for that idea!! We have decided to upgrade mattress - BUT we do still need to deal with the odor in the carpet above the pass-thru that was damp. I have already sprayed a mixture of bleach and water. It did help - but the smell from the bleach was a little overwhelming. If I can find out there wouldn't be a chemical reaction between the bleach I've already put down and the alcohol, I would like to use that. It would be more friendly on the carpet as far as bleaching out the color(didn't do when I used as I diluted enough to not cause). Thank you, Kim
[/quote]
If you do "upgrade" the mattress let everyone on the post know what you came up with. There are some posts on memory foam mattress toppers,upgrades, etc..., but a new mattress idea always seems to be of interest on the forum.


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## BoaterDan

It seems like we're missing something. I know the 31RQS has the front bed over the storage area. I imagine other models do too. I'm extremely suspicious that this problem is really just condensation of some sort. Heating the pass through?!









I've had a time or two where the windows weren't cranked closed all the way and water leaked in. Apparently, they're fine in the rain if they're really open or closed tightly, but leak if not snugged down. Water basically ran down the wall and under the mattress.

Of course, once that mattress soaks up some water it really has to get dried out very well. I'm wondering if maybe there was a small leak at some point in the past, and you never noticed the moisture on the bottom side of the mattress until it started smelling foul.


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## thefulminator

BoaterDan said:


> It seems like we're missing something. I know the 31RQS has the front bed over the storage area. I imagine other models do too. I'm extremely suspicious that this problem is really just condensation of some sort. Heating the pass through?!
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I've had a time or two where the windows weren't cranked closed all the way and water leaked in. Apparently, they're fine in the rain if they're really open or closed tightly, but leak if not snugged down. Water basically ran down the wall and under the mattress.
> 
> Of course, once that mattress soaks up some water it really has to get dried out very well. I'm wondering if maybe there was a small leak at some point in the past, and you never noticed the moisture on the bottom side of the mattress until it started smelling foul.


Kimbo, Dan has a point. If you are planning to replace the mattress you might want to experiment a little with the old one first. That might save you some money and aggravation. Flip the mattress over so the dry side is down. See if it gets damp when you guys aren't sleeping on it. You could put a pan of water or partially fill a sink for a humidity source to simulate occupation. If it does get damp, then it is a problem with condensation from the pass through. If it doesn't get damp then maybe put it on top of some 1x or 2x boards to lift it off of the platform and see if the mattress is absorbing moisture from the air without the platform cover affecting it.


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## kimbo1020

raynardo said:


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> 
> ....just a thought....._










That's it ~ can't believe I missed that!!! Ha Ha!


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## kimbo1020

thefulminator said:


> It seems like we're missing something. I know the 31RQS has the front bed over the storage area. I imagine other models do too. I'm extremely suspicious that this problem is really just condensation of some sort. Heating the pass through?!
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I've had a time or two where the windows weren't cranked closed all the way and water leaked in. Apparently, they're fine in the rain if they're really open or closed tightly, but leak if not snugged down. Water basically ran down the wall and under the mattress.
> 
> Of course, once that mattress soaks up some water it really has to get dried out very well. I'm wondering if maybe there was a small leak at some point in the past, and you never noticed the moisture on the bottom side of the mattress until it started smelling foul.


Kimbo, Dan has a point. If you are planning to replace the mattress you might want to experiment a little with the old one first. That might save you some money and aggravation. Flip the mattress over so the dry side is down. See if it gets damp when you guys aren't sleeping on it. You could put a pan of water or partially fill a sink for a humidity source to simulate occupation. If it does get damp, then it is a problem with condensation from the pass through. If it doesn't get damp then maybe put it on top of some 1x or 2x boards to lift it off of the platform and see if the mattress is absorbing moisture from the air without the platform cover affecting it.
[/quote]

I am away on a trip home - but my husband is doing just that ~ experimenting with old mattress. He put some type of insulating foam board inside pass-thru between the alum frame while he removed mattress for the day and to dry out carpet with alcohol(as suggested)and a fan on the area. Then he replaced mattress and slept on it. He said it has been dry under the mattress so far(3 days now). He will continue this to see if relieves the problem. He has also decided to raise the mattress on some type of fabricated low profile frame ~ just to insure air flow. Then will come the new mattress. Thank you so much for all your help. Much appreciated!!! A note about possible window leaking.....there are no windows directly near bed ~ so don't believe that comes into play. Husband also covered mattress with plastic mattress cover to insure seeing the moisture if any ~ that would develop since changes were made. I will of course keep all posted of outcome for others that may experience this same issue.


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## CamperAndy

A plastic mattress cover will stop the moisture migration through the mattress and as long as it does not make too much noise then it should help a great deal.


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## thefulminator

I'm glad we were able to help.

What has the outside temperature been while he has been testing vs. when you had the problem?


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