How to Prevent Moisture and Mold Under an RV Mattress
Moisture buildup under an RV mattress is a common problem, and if left unchecked, it can lead to mold and mildew.
This not only damages your mattress but can also create health issues like allergies and respiratory problems.
The good news is there are simple and effective ways to prevent it, keeping your RV bed dry and comfortable for years to come.
Why Does Moisture Build Up Under an RV Mattress?
Moisture collects under RV mattresses due to condensation. This happens when warm air inside your RV meets the cooler surface of your mattress and bed platform.
Since RVs have limited airflow compared to houses, moisture can easily become trapped, especially in colder weather or humid environments.
If you’ve ever woken up to a musty smell in your RV bedroom or noticed damp sheets, there’s a good chance moisture is accumulating under your mattress.
Over time, if this issue isn’t addressed, mold can start growing, leading to costly damage and potential health concerns.
Signs of Moisture and Mold Under Your Mattress
It’s important to catch moisture issues early before mold spreads. Here are some warning signs to look for:
- A damp or musty smell in the bedroom area.
- Visible mold or mildew spots on the mattress or bed platform.
- A wet or clammy feeling when touching the mattress or sheets.
- Warping or discoloration of the bed platform.
- Increased allergy symptoms, like sneezing or congestion, when sleeping in your RV.
If you notice any of these signs, take action right away to prevent further damage.
6 Ways To Prevent Moisture & Mold Under RV Mattresses
Moisture prevention is key to keeping your RV mattress in good condition. Here are the best ways to stop condensation and mold before they start.
1. Increase Airflow Under the Mattress
Raising the mattress off the platform allows air to circulate and prevents moisture from getting trapped. Some ways to do this include:
- Using a bed slat system or ventilated mattress foundation
- Adding a mattress underlay (click to view on Amazon) or a similar breathable material
- Propping the mattress up occasionally to air it out
- Drilling small ventilation holes in the bed platform (if possible) to improve air circulation

2. Use a Dehumidifier or Moisture Absorbers
Controlling the humidity inside your RV is one of the best ways to prevent moisture buildup. Here’s how you can do it:
- Run a small dehumidifier to pull excess moisture from the air
- Place moisture absorbers like DampRid (click to view on Amazon) or silica gel packets near the bed
- Open windows or use roof vents to improve air circulation, especially after cooking or showering
If you frequently camp in humid environments, a portable dehumidifier can make a huge difference in maintaining dry conditions.
3. Use a Mattress Protector
A waterproof or moisture-wicking mattress protector (click to view on Amazon) can help keep condensation from soaking into your mattress.
Look for one that is breathable to avoid trapping heat. This added layer not only protects against moisture but also helps with allergens and dust mites, keeping your sleeping area cleaner and more comfortable.
4. Ventilate the RV Regularly
Proper airflow throughout the RV prevents condensation from building up.
Ventilate easily by:
- Running ceiling fans or using portable fans to circulate air
- Keeping windows or vents open whenever possible
- Running the furnace or AC to regulate indoor temperature
- Opening up cabinets and under-bed storage areas to avoid trapped moisture
Even in colder months, it’s important to let fresh air in to prevent condensation buildup.
5. Use Reflective Insulation
If cold air from the RV storage compartments is causing condensation under the mattress, adding a layer of reflective insulation like Reflectix (click to view on Amazon) between the bed platform and mattress can help reduce temperature differences.
This is especially helpful if you camp in colder climates where the temperature contrast between the inside of your RV and the storage area is more extreme.
6. Check for Water Leaks
Sometimes, moisture buildup isn’t just from condensation, it could be caused by an unseen water leak. Regularly inspect your RV for leaks near windows, doors, or plumbing areas.
If water is seeping into the RV, no amount of dehumidifiers or ventilation will completely solve the problem until the leak is fixed.

What to Do If You Already Have Mold Under Your Mattress
If you notice mold or mildew, act fast to stop it from spreading. Here’s what to do:
- Remove the mattress and check the bed platform for signs of damage.
- Clean the affected area using a vinegar-water solution or hydrogen peroxide to kill mold and bacteria. Avoid using bleach, as it can damage materials and create strong fumes in a small space.
- Allow everything to dry completely before placing the mattress back on the bed platform. Set up fans or open windows to speed up the drying process.
- Consider replacing the mattress if it has significant mold growth. A contaminated mattress can continue to cause health issues even after cleaning.
Extra Tips for Long-Term Prevention
- Store your RV in a dry location when not in use – If possible, keep your RV in a climate-controlled storage unit or use an RV cover that prevents moisture buildup. Parking in a dry, well-ventilated area reduces the risk of mold growth.
- Use moisture-wicking bed sheets and blankets – Opt for breathable fabrics like cotton or bamboo that help wick away moisture and prevent condensation from accumulating in your bedding.
- Regularly inspect your mattress and bed platform – Check under the mattress every few weeks, especially in humid weather or after long periods of storage. Catching moisture early prevents bigger issues down the road.
- Avoid placing wet clothes or towels near the bed area – Wet items increase humidity inside the RV, which can lead to moisture collecting under the mattress. Hang damp clothes outside or use a designated drying area.
- Run your RV’s ventilation fans even when not in use – If your RV is parked for a long time, consider using a solar-powered ventilation fan (click to view on Amazon) to keep air moving and prevent moisture from becoming trapped.
- Use desiccant packs in storage areas – Placing silica gel or other moisture-absorbing products in your under-bed storage or closets helps keep the entire sleeping area dry.

Final Thoughts
Moisture and mold under an RV mattress can be frustrating, but with the right prevention methods, you can keep your sleeping area dry and comfortable.
Prioritizing airflow, controlling humidity, and using breathable materials will help prevent condensation from becoming a problem.
If mold does develop, addressing it quickly will keep it from causing long-term damage to your RV and health.
Frequently Asked Questions
Why is moisture such a big problem under RV mattresses?
Moisture buildup leads to mold and mildew, which can cause health issues and damage your mattress.
Since RVs have limited airflow, trapped humidity under the bed can quickly turn into a breeding ground for mold.
How can I tell if my RV mattress has moisture or mold?
Signs include a musty smell, visible mold spots, damp bedding, discoloration of the bed platform, and even allergy symptoms like sneezing or congestion while sleeping in the RV.
What is the best way to keep moisture from accumulating under my mattress?
Improving airflow is the most effective method. Use a ventilated mattress foundation, mattress underlays, or raise the mattress slightly off the platform. Running a dehumidifier or using moisture absorbers also helps.
Can I just flip my mattress occasionally to prevent mold?
Flipping or airing out your mattress helps but isn’t a long-term solution. You need consistent airflow underneath the mattress, which can be achieved with slats, underlays, or ventilation holes.
Will a mattress protector help?
Yes, but it depends on the type. A breathable, moisture-wicking mattress protector is best. Avoid fully waterproof covers that can trap condensation inside.
Do I need a dehumidifier if I’m only using my RV occasionally?
Yes, especially if you store your RV in a humid area. Moisture can still accumulate when the RV is not in use, so using a small dehumidifier or moisture-absorbing products is a good idea.
Can reflective insulation under the mattress help?
Yes! If cold air from the storage compartment is causing condensation, adding reflective insulation between the platform and mattress can reduce temperature differences and limit moisture buildup.
What should I do if I find mold under my mattress?
Remove the mattress, clean the area with a vinegar-water solution or hydrogen peroxide, let everything dry completely, and improve ventilation before putting the mattress back. If the mold is severe, consider replacing the mattress.
How often should I check under my mattress for moisture?
It’s a good idea to check every few weeks, especially in humid conditions or if you’ve been camping in colder weather. Catching moisture early prevents bigger problems.
Can I prevent moisture under my mattress while storing my RV?
Yes! Store your RV in a dry location, crack a vent for airflow, and use desiccant packs or a small dehumidifier inside. Keeping moisture levels low while in storage will prevent issues when you return.
Have any more ideas for preventing and getting rid of moisture under RV mattresses? Leave a comment below.
The best way to revive moldy RV furnishings and mattress’s
bag them is large airtight bag and activate some chlorine dioxide. I have used this product in my RV several times and it destroys mold. It is a gas, and you need to exercise some precaution in its use.
I’m looking not for a cheaper solution to hypervent/plastic landscaping material, but a more environmentally friendly alternative. I’m wondering if ridged cork insulation with solid or channeled (for more air flow?) under the mattress would work.
I think that’s a really cool idea actually. You could maybe put cardboard under the cork to help increase airflow but cork would be a fantastic material to use as a mattress underlay.
I saw this on a different blog post about preventing mold growth under RV mattresses, and when I read your comment about being interested in something more environmentally friendly for airflow, I thought you might appreciate this recommendation. As your post was dated in March, I imagine you may have already found this solution or something better.
It’s a coconut coir matress pad/bed rug. They sell them on the Natural Home by the Futon Shop online store.
https://www.thefutonshop.com/catalog/product/view/_searchanise/1/id/16509/s/coirpad-coconut-coir-mattress-pad-bed-rug/?source=aw&awc=19236_1654040825_df3226c6dd6078e94967b28570f0fbf7
I live in very humid Blue Ridge Mountains and am getting ready to throw my coconut fiber away cuz it’s moldy. I think maybe they are better for more dry weather.
We use Dendry under our boat mattress and run a dehumidifier and still get condensation under the mattress. Definitely have to keep an eye on it, even when using Dendry.
I just read that you should take the plastic off your new RV trailer mattress, but should I leave the plastic underneath the mattress so there won’t be mold?
Hi John,
The most important thing its to get some air under there so it stays dry. It think leaving the plastic might trap moisture inside the mattress.
I would remove the plastic and either get a mattress underlay if you’re a full time RVer, or just make sure you lift the mattress to get some airflow underneath when it’s in storage.
I need help. I sleep in my horse trailer and I want to put a mattress in the gooseneck. I bought a waterproof storage zipper bag to keep mattress in it so it doesn’t get dusty etc., but how do I deal with possibility of mold? Buy an air mat for under mattress and put it inside the storage bag? Or put it under storage bag between gooseneck floor and bag? Or both?
Hi Theresa,
If it fits, I would put the air mat in the bag with the mattress to keep it clean as well.
As for mold, putting desiccant bags like these (click to view on Amazon) in the bag with the mattress should help absorb moisture and keep the mattress dry.