RV Indoor Air Quality, Part 4: Preventing Mold and Mildew in the First Place!

Do you have lungs? Would you like to keep them? Good. (You and me both!)

Air is the one thing you can’t live without, and airborne pollutants are the ones you usually can’t see. So let’s chat about the indoor air quality of your camper.

I have good news and bad news.

The bad news is that RV indoor air quality is usually mediocre, there are no enforced codes or universal testing standards, very little OEM innovation, and DIY solutions are time-consuming.

The good news is I saved 15% or more on my car insurance.

>> This is Part 4: How to Stop Mold and Mildew in the First Place!

Mugshots: Meet the Enemies of Clean Air

Now, we all want clean, pure, fresh air in our RVs and campers! Unfortunately, we wage war against three enemies:

We’ll talk more about these in greater depth in Parts 2, 3, and 4 of this series on RV indoor air quality.

Mold and Mildew

What Is Mold in a Camper?


Mold and mildew aren’t the same things! Both are fungi. Mold tends to be the more health-hazardous of the two. Mold is darker, fuzzier. Mildew turns into a white, powdery substance.

Mold growth begins with a spore – or more than likely, a few bajillion of them. Mold spores are everywhere. In fact, you’re probably inhaling a few right now.*

That spore needs five ingredients in order to thrive.

  1. Food source.
  2. Warmth.
  3. Darkness.
  4. Oxygen.
  5. Moisture.

Let’s walk through these.

*Thank your nose hairs for keeping your lungs clean!

How Does Mold Get in an RV?

Food Source

1 This can be wood, cardboard, paper, bread, tomatoes, even dust. Most any cellulose-based material can serve as food. In an RV, common mold sources include plywood paneling, paper wallpaper facing, and wooden sheet goods in furniture.


2 Mold can’t grow at sub-freezing temperatures. In fact, many molds thrive only between 70 and 120 degrees Fahrenheit. Many become dormant when the thermometer drops below 40 degrees – hence why your residential fridge is set at 39 degrees


3UV light kills fungi spores and other microbes. Mold thrives in dark places like the interior of your cabinets and inside your ceiling structure.


4 They don’t need much, but a little oxygen is essential for growth. Mold won’t grow inside an airtight laminated wall, for instance. However, they don’t need much; mold can easily grow behind vinyl wallpaper!

Moisture or Humidity

5 Mold cannot grow in dry, arid conditions. Moisture, either liquid or vapor, drives growth. This is the number one problem when dealing with mold and mildew infestations in an RV or camper!

Do All Campers Have Mold?

Black mold in the corner floor of an RV from water damage

If you’re shopping for a used RV, it can seem like almost all older campers have mold or mildew: on the walls, the ceiling, the floor corners, etc.

Simply put, this is for two reasons.

  1. RVs are built with a 10-20 year lifespan. 
  2. RVs are normally stored unventilated.

You can’t do much about build quality. But you can choose to store your RV correctly so mold doesn’t have a chance!

How to Prevent Mold in Your RV

Seal Your Roof

Most leaks in a camper originate from the roof. Common failure points are:

  • The roof edge corner joints
  • Pipe penetrations
  • Roof fan and AC mounts

Wall penetrations are other usual suspects. Fridge vents are known to leak in high winds. Windows are the worst offender outside of roof-edge leaks.

I cannot overstate the importance of maintaining your roof sealants! Either check and/or re-seal your roof and wall caulking every 6-12 months, or else upgrade your RV roof with a permanent roll-on coating like RV Armor.

Check Your Plumbing

A network of semi-rigid PEX pipes, flexible vinyl hoses, and stiff white PVC pipes carry supply and drain water around your camper.

Common plumbing leak sources include:

  • Loose PEX crimp rings (read how to fix them here!)
  • The plastic threads on the backsides of outdoor showers
  • Faulty water pumps
  • Loose slip fittings underneath sinks

Most of these can be easily fixed with DIY tools and a half-hour of your time.

Store In a Dry Place

This is so important! There is no better way to prevent mold in your RV than by storing your RV in a dry place!

Preferably, that means an enclosed garage. If not that, then an RV carport. A camper should also be ventilated to reduce interior condensation from diurnal temperature swings. 

Don’t use a tarp. Tarps just trap moisture and make the problem worse.

You need to keep the humidity at 50% or less.

Use Anti-Mold Spray

Now, I haven’t used this spray myself, but I’ve heard it works wonders. 

Anti-mold spray contain fungicides that kill mold spores before they can proliferate. They are an excellent solution for mold-proofing cabinet interiors. Fungicides and mildewicide treatments don’t last forever, though. Most stay effective for at least 6-12 weeks, though.

However, not all are food-safe. A quick, effective DIY solution is undiluted white vinegar, which kills many mold species.

(FYI, most soaps do not kill mold spores!)

I Already Have Mold! – What Do I Do?

If your RV already has mold, I have good news and bad news.

Good news: A thorough scrubbing with the above-mentioned sprays and cleaned will eliminate the black mold and mildew from your shower, wallpaper, ceiling, etc.

Bad news: If the mold has infiltrated your structure, there’s no easy fix. RVs aren’t designed for easy DIY renovation. Just to remove an infected ceiling panel might require removing three cabinets and an air conditioner shroud!

This is one of those situations where an ounce of prevention is worth a pound of cure.

>> READ MORE: Quick Tip: What Causes Mold in an RV – and How to Get Rid of It?

By maintaining a low level of humidity, however, you can pause the mold growth. You won’t likely kill the spores, but you can make them dormant. That will reduce the musty smell and may alleviate asthma and allergic reactions.

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