Mattress ventilation?

[Vagabound]

In my truck I have a bed platform made out of plywood and two-by-fours. At the moment, on top of that I have placed a normal bed mattress. Mattress lays directly on top of the plywood. Today is the day for me to remove all of the stuff and do a lot of painting to include the bed platform.

Over the last few months, someone has mentioned that I should drill large holes in the plywood bed platform to allow the mattress to ventilate. I have given that some thought. So far, it seems to me like a solution in search of a problem. In other words, a non-issue and not worth doing. 

First, I don't think there's going to be much ventilation through eight or ten hole-saw-sized holes. Second, it would seem to weaken the bed platform without much benefit. Third, I think there are solid bed platforms all over the world that have no ventilation holes in them. Fourth, I'm as busy as can be, so if there's anything I don't need to do, I want to skip it.

On the other hand, this is my last easy chance to drill these holes if I'm going to do it.

What say you and why?

Tom

 

[dr_nelson]

Rolling Earthship's mattress was damp where it sat directly on top of a solid plywood (saw a youtube vid of him) After drilling holes and making the plywood look like swiss cheese, he said he no longer had any issues. Of course, I think he was in a climate where winter can be pretty cold.


I plan on doing the swiss cheese, too, and not only because I am Swiss. Besides taking some time to drill the holes, I don't see any disadvantages. Actually, you'll have less potential for mold and even save a little bit of weight hauling around.

Do it. Seems the perfect time for you...

 

[grandpacamper]

My cut at is this, I used 2x4's for framing, 3/4 inch plywood board. I always build for strength, I live in a somewhat humid area - Pacific Northwest. Utah was dryer than a popcorn fart. Didn't need to worry. I drilled 16 holes spaced evenly about 1 1/4 in. in dia. Better safe than sorry, but I was just following the advice of others who knew more than me. We seem to get mold everywhere here. That's why the colors of the Oregon Ducks is green/yellow matches the fuzzy stuff on all the roofs.

 

[MrNoodly]

Utah was dryer than a popcorn fart.  Didn't need to worry.

Yeah, except for occasional forays to the coast, I'm dedicated to living in low humidity regions. It prevents most mold/mildew/odor/leak/comfort problems.

My mattress has been on a solid platform for four years. No problems. 

However, if someone decides to do the Swiss cheese thing to their bed platform, it will still be plenty strong.

 

[Gary68]

only an issue in high humidity areas and/or buddy heater use

http://www.ebay.com/itm/like/151931696455?lpid=82&chn=ps&ul_noapp=true

 

[Vagabound]

All: Thanks for the quick replies. Seems like sound reasoning to me.

grandpacamper: Popcorn fart. Thanks. I really needed a laugh this morning. So in your story, what happened? What was the result?

Tom

 

[SternWake]

The humidity which makes a matterss get moldy mildewy, comes from body respiration. It is not a soultion looking for a problem but a vaild concern with a solid foam rubber mattress.

When there is a warm body giving off moisture and a solid unventilated cold plywood platform below, the bottom of the mattress will, after a week, feel as damp as if you pissed the bed every night, even if you are in the land where popcorn regularly farts.

A regular household mattress is some foam rubber on top of coiled springs, and the sides of the mattress might even have the little ventilation 'speakers'. which largely mitigate the issue, as warm moist foam is not in direct contact with a cold surface anbd the foam is not moist from ambient humidity, but from the warm body on top of it.

My bed platform is only plywood, no 2x4's. No way in hell was I cutting ventilation holes. I instead lift my mattress in the daytime to allow moisture to evaporate, but I have gone too long without doing this, especially initially when I was unaware of the issue.

Here is another solution:
http://www.defender.com/product.jsp?path=-1|2276179|2276186&id=1818021

The colder the plywood platform, the worse the moisture issue appears.

Lately instead of lifting my mattress, when parked facing north, I lift my rear curtain, and push the bottom of mattress up against the windows, which I opened. Heat from the sun and good airflow makes for a happy mattress underside

 

[Optimistic Paranoid]

This was discussed in a thread several years ago:

https://vanlivingforum.com/Thread-Mattress-platform-condensation

This is a real issue in the boating world.  A Google search on "Mattress Condensation" will turn up numerous threads on sailing and cruising forums discussing this.  There are several remedies.  Here's a few pointers:

https://www.nestbedding.com/blogs/news/6926850-why-is-it-damp-under-my-memory-foam-mattress


http://www.defender.com/product.jsp?path=-1|2276179|2276186&id=1818021

http://www.frolisleepsystems.com/products1.html

 

[highdesertranger]

Vagabound check under your mattress, is it damp? if it is drill the holes now, if it isn't wait and see if it ever becomes a problem checking frequently. it seems to be a problem with foam mattresses not the traditional box spring mattress. highdesertranger

 

[user 37446]

Yep, that's the way to do it. Search first...There's not much that hasn't been asked or discussed before.

 

[Vagabound]

SternWake:  I agree that the moisture problem will be less of an issue, or a non-issue, with a standard house mattress compared to the other types that are more commonly used in vandwelling, boating, etc. Otherwise, it sounds like you're doing far more mattress calisthenics than I'd be interested in doing.

HDR: I was laughing reading your reply because it was just so simple and practical. Is it wet under there or not? Take a look. 

It was also funny that you seem to be on "practical duty" today. Normally that is John/OP's function. . The answer to The $64,000 Question: No, it was not damp under my mattress, after about three months of use in that position. That said, have been in popcorn fart territory, so who knows what would happen when I go to Oregon or Florida, both of which are on the to-do list.

John/OP:  Thanks for looking up and offering those alternate solutions.

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Go / no go time is upon me. Although I don't think it's going to be an issue in my case, and I have half inch plywood as a base, I think I'm going to drill several holes just to be on the safe side. I'll stop short of Swiss cheese though. 

Thanks everybody. It really does help to have a group like this to bounce something off of, especially when doing solo work out in the desert.

I'll update this somewhere down the road once I know the verdict.

Have a great day,

Tom

 

[DLTooley]

Just flip the mattress every time you change the sheets. If there is a problem you will see it.

 

[MrNoodly]

My bed is an 8" thick standard foam mattress from Mattress Firm. There's a 4" memory foam topper. Those are zipped into a "bed wetter bag" in case I spill something or rain gets in the van. Over that is a 100% cotton mattress pad to provide some breathability between me an the mattress. Finally, there's a 100% cotton fitted sheet. All of that is on a solid platform. The platform is 2x2s sandwiched between plywood. The top plywood sheet lifts up so I can store things like my atlases inside the platform. The platform sits on a steel bed frame 12" off the floor. Tool boxes and bins are under the frame. Like I wrote earlier, I have NO problem with mold or mildew. Several times I've stripped everything down to see if there's anything to worry about. There hasn't been. Oh, and I sleep clothed. So if I'm respiring moisture, maybe my clothing is absorbing it rather than my bed.

 

[deadwood]

My bed is a 6'' foam mattress that I got at a local mattress place on clearance. I'm in AZ so there hasn't been a moisture problem yet. I can see where being in a high humidity area can make a difference. Then you aren't just worried about your mattress getting damp your worried about your whole rig.

I spent a month this last winter in San Francisco and it was humid or raining a good part of the time. What I did to combat it was to run my A/C any time I was driving. Even though it was chilly out I just had the A/C on but turned the temp up so it wasn't cold air. The vans A/C unit worked like an amazing dehumidifier.

For the bed I haven't had any issues yet. My bed support is just plywood with some indoor/outdoor carpet stapled to it. But like MrNoodly my mattress has a protective cover over it to protect it from spills. If it's keeping spills from getting to the mattress I imagine it is keeping my own perspiration from getting to the mattress as well.

Between running the A/C when I need to fight humidity and having the mattress protector on I haven't had any problems so far. I think good ventilation is key as well. But if you are just worried about the bed I would definitely try a mattress protector. It's cheap insurance to protect the mattress.

 

[Optimistic Paranoid]

Just flip the mattress every time you change the sheets. If there is a problem you will see it.

If you have a memory foam mattress, you can't do this.  A memory foam mattress is not pure memory foam all the way through.  It is a layer of memory foam bonded to a thicker layer of regular foam.  The memory foam needs to stay on top, so these mattresses are never flipped like the old ones were.

 

[user 37446]

Quite true on the memory foam that's done in layers. My mattress is one of those "solid" latex rubber ones, so its the same density and materials all the way through. Weighs a lot but can be flipped if needed.  Interesting thread though, I had not heard of the moisture problems before that some report.

A quick search (Google) found that both the Airstream forum and the Cruiser (boat) forum have threads on this, so it must be more common.

Airstream: http://www.airforums.com/forums/f458/mattress-moisture-problem-85283.html

[font=verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif]Mattress Moisture Problem?[/font]

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[font=verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif]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?[/font]

[font=verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif](First Reply)[/font]

[font=verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif][size=small][font=verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif][font=tahoma, verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif]

 12-01-2011, 06:03 AM[/font]
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[font=verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif]Ridgerunner3
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[font=verdana, geneva, lucida, 'lucida grande', arial, helvetica, sans-serif]"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."
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[SternWake]

Otherwise, it sounds like you're doing far more mattress calisthenics than I'd be interested in doing.

True, It is kind of a pain.  The upsides are when I do this none of the sun's heat enters the van from the back windows, and it makes a nice backrest if I have company, and they do not have to sit on my bed.  

 Returning it to bed mode is super simple, just pull and flip the covers back.

It does block my rear speakers when raised too, but I could easily  move them.

While the dampness accumulated in the mattress might be worse in humid environments, the moisture source is one's body, NOT ambient humidity.  Temperature of the wood platform will have a bigger difference in how wet the bottom of solid foam mattress feels, compared to whether the mattress in in the PacNW, or popcorn fart land.

 

[TrainChaser]

Vagabound, you say that you have a 'normal bed mattress'.  If you check out a couple of regular mattress stores, you will find that most of them sell the bottom support section, that used to be called the 'box springs', but they aren't box springs anymore, they are just plywood boxes covered with a layer of fabric that matches the mattress.  Pretty much what you're describing in your truck.  I lived in a van for seven months with a twin Serta on a solid plywood platform, in winter, and had no issues.

I don't know anything about Memory Foam, but if they don't absorb body moisture in S&B homes, why would they do so in a van?  If a mattress pad is recommended for this type of mattress, it should be what is would be collecting any body moisture.

The average 165-lb person expires about 350ml (12 oz) of body moisture through the skin every 24 hours.  If you're sweating the whole time, add about 100ml / 4 oz more.  If you're in bed 1/3 of each day, you're expiring 4 oz (1/2 cup) of skin moisture during that period.  If you are covered with plastic or foil (and are every night) that could be a problem, because water seeks the lowest point it can find.  But moisture tends to evaporate, especially from a near-gaseous form.  And it would be worse if you were a prisoner and couldn't open the doors and windows for ventilation, which I'm assuming is not the case.

This winter, I tried an experiment here in cold, WET western WA.  I bought six feet of 48"-wide Reflectix and laid it on my bare mattress, then covered it with a mattress pad, and then a sheet.  Then I had another sheet, and five wool blankets (no heat here at night).  At first, I flipped the blankets down halfway when I got up, to let any moisture dry.  Then I stopped doing that and flipped them up.

Results:  NO MOISTURE PROBLEMS.  This in a ratty old mobile home that has roof leaks in every room, and I'm sure all of the pink fiberglass ceiling insulation is sopping wet.  Every time I get into that bed, the sheets are dry, and due to the Reflectix, I warm up right away.

 

[Optimistic Paranoid]

I don't know anything about Memory Foam, but if they don't absorb body moisture in S&B homes, why would they do so in a van?  If a mattress pad is recommended for this type of mattress, it should be what is would be collecting any body moisture.

Condensation & mold only seems to be issues when the space under the mattrest is colder than the space above it.  In an S & B where the air temp under the bed is the same as the rest of the room, it isn't a problem.

 

[TrainChaser]

OP: "Condensation & mold only seems to be issues when the space under the mattrest is colder than the space above it."

That sort of makes sense -- all the space under my bed in my vans was 'insulated' with boxes of stuff!