It’s every vanlifer’s worst nightmare. There’s a leak somewhere, and a good rainstorm brings a steady drip of water that might not seem like a big deal at first. But that water ends up leaching into some dark, unventilated corner of your van, and before you know it you’ve got a mold problem.

This is exactly what happened to us recently. Since day one we’ve had issues with our aging rubber door seals – excessive wind noise in the front, and water leakage in the back. Every time it rained, a trickle of water dripped down our rear doors and soaked the edge of the flooring underneath our bed. Replacing the door seals actually made the problem worse, since they don’t make one of the pieces anymore (some creative caulking around the top of the door seal finally fixed the issue).

But after a year on the road the damage was already done. We were rearranging the trunk one morning when we noticed some white fuzz peaking up between the floorboards. Mold!

The leaky door seals had caused water to soak into the subfloor, and mold started growing. We began peeling up our laminate flooring bit by bit, revealing a dusting of white and greenish mold that continued along the left side up towards the front of the van.

moldy van subfloor
We also found a little mold on the subfloor underneath our kitchenette – until our aim improved, we frequently spilled water under here while refilling our water tank.

Not wanting to deal with a mold-infested living space, we decided to tear everything out and completely redo our floor. In the process, we took a few extra steps to make sure that mold will never again be a problem.

Here’s everything we’ve learned about mold prevention in a van, the steps we took in our new flooring install, and what you can do to stop mold from taking hold in your van build.

Vanlife Mold Prevention 101

The idea of mold growing somewhere in your van without your knowledge is definitely worrisome. But if you take a few easy preventative measures, you can go a long way towards stopping the worst mold problems before they start.

Make Sure Your Van is Properly Sealed

van sealed against leaks_1200x750

Leaks are bad news, and not just because of the annoyance of water dripping on you and your belongings. With any leak, there’s the danger that moisture is collecting somewhere hidden, which is a big cause of mold.

Moisture + Organic Material + Lack of Ventilation = Mold

This is exactly what caused the bulk of our mold problems – leaky rear door seals. If we had dealt with this as soon as we noticed it instead of waiting for almost a year, we might have avoided the worst of our mold.

Check your door seals for leaks. Make sure you use plenty of sealant over any holes you drill in your roof for mounting solar panels or installing a vent fan. Fix any issues that crop up.

Make Good Ventilation a Priority

vanlife ventilation

Mold does best in dark, poorly ventilated areas. If you allow too much moisture and condensation to collect inside your van, you’re creating a prime environment for mold spores to take hold and thrive.

The number one thing you can do here is install a good roof ventilation fan. Vent fans suck out moist air and pull in fresh air, creating airflow that really helps keep things relatively dry. They also provide ventilation while cooking, and help keep your van cool. We almost never turn ours off.

We recommend the Maxxfan 6200K, since it has a built in rain cover that allows you to keep it running in all weather – a must have feature for living in a van, in our opinion.

If you don’t want to throw down for a vent fan just yet, we highly recommend at least getting some sort of 12V fan. That combined with an open window will go a long way towards creating proper ventilation.

Treat Hidden Surfaces with a Mold Preventative (or two)

mold preventative products

Treating hidden, mold-vulnerable areas (like your subfloor and behind your walls/ceiling) with a mold preventative helps protect you from mold even if moisture does find its way to these areas.

After we found the mold on our subfloor, we did a ton of research on this. We found out about a product called Concrobium, which is a natural, non-toxic mold killer and preventative spray. Unlike bleach or vinegar, which only treat surface mold, Concrobium penetrates deep into wood fibers to kill mold spores at the roots and prevent future mold from growing.

Spraying down your subfloor and the backs of your wall and ceiling paneling with Concrobium can stop mold growth before it starts. Concrobium is available at any big box hardware store, but it’s usually cheaper on Amazon.

Another product that can help prevent mold growth is Zinsser Bullseye 123, a paint primer that creates a mold-resistant film. Painting your subfloor with Zinsser Bullseye can help prevent mold from penetrating.

We wanted to be totally safe with our new subfloor, so we used both Concrobium and Zinsser Bullseye. We also treated the interior of our kitchenette with Concrobium, since this is a naturally wet area of our van.

Installing a Mold-Proof Subfloor and New Vinyl Plank Flooring in Our Van

First, We Gutted the Van and Ripped Out the Old Flooring

gutted van

This went a lot quicker than we expected – it only took us a few hours to dismantle the furniture and rip out all the flooring and insulation. Luckily, we built our furniture to be somewhat modular, so once we undid all the brackets holding it down we could pretty much slide it right out. We also had to unhook most of our electrical system.

Next, We (Finally) Added Sound Deadening to Our Van

vanlife sound deadening installed

Not adding sound deadening before building our van was a major regret of ours because we had a ton of road noise. So while we didn’t have a floor we decided to add it in.

We didn’t have time to order actual sound deadening material online. Instead, we went to Lowe’s and picked up Peel and Seal flashing tape from the roofing aisle.

vanlife sound deadening

This stuff is very similar to commercial sound deadeners, but it’s easier to find and tends to be cheaper. Peel and Seal is about $1.28 per square foot, versus $1.77 for Noico and $2.19 for Fatmat. We used three rolls for the floor and the front door panels. Total cost: $48.

Installation was fairly simple. We cut strips of Peel and Seal, and pressed it in place using a small handheld roller tool that we had on hand. There’s no need to cover every inch of floor, because the mass of the sound deadener prevents surrounding areas from vibrating.

vanlife sound deadening installation

After installing this, our van is definitely quieter. We can’t compare its effectiveness to Noico or Fatmat, but it gets the job done.

Then, We Laid Down a New Layer of Reflectix for Insulation

new reflectix

We know, we know. Reflectix needs an air gap to really be effective as a radiant heat barrier. But it’s still about R-1 by itself, it’s nice and thin so it won’t take up too much height, and it’s better than no insulation.

(Read our detailed post on different vanlife insulation materials for more information on Reflectix and its proper uses.)

To install the Reflectix we cut it to fit, sprayed the underside with 3M High Strength 90 adhesive, laid it down in the van, and taped the seams with 3M Foil Tape.

Next, We Measured, Cut, and Test Fit the Subfloor

subfloor test fit

We went with ⅜” plywood this time. Since the vinyl flooring we got is much thinner than laminate, the thicker subfloor provides more strength for screwing down our furniture.

In our initial flooring install, we used cardboard templates to trace the subfloor. This time, we were able to use the original subfloor as a basis to trace the van’s contours onto the new ⅜” plywood. Because the living space in our van is 6’x10’ and plywood sheets are 4’x8’, we needed two sheets of plywood to make the four interlocking pieces of the subfloor.

Once we had the subfloor traced, we cut it out with a jigsaw and test installed it in the van to make sure it fit. We had to tweak some corners here and there, but overall it was pretty close.

Then, We Mold Treated the New Subfloor and Installed it in the Van

mold treat subfloor

First, we soaked every inch of the subfloor with Concrobium mold killer/preventative and let it dry overnight. Then, we painted it with Zinsser Bullseye 123 mold resistant primer.

The Concrobium kills existing mold spores deep inside the wood fibers and helps prevent new ones from taking root. The Zinsser Bullseye seals the wood and prevents mold from penetrating. With both of these on our subfloor, we shouldn’t have to worry about future mold problems.

After treating the subfloor, we installed it in the van. To make sure the subfloor stayed together and level for the vinyl flooring, we filled the cracks between the subfloor pieces with Gorilla Construction Adhesive caulking, leveled it out, and covered it with Gorilla Tape.

Next, We Installed Our New Vinyl Plank Flooring

vanlife vinyl flooring install

Putting in a new floor gave us the opportunity to rethink the material that we used. When we originally built our van, we used laminate flooring. Laminate is cheap, works well, looks good, and we were happy with it overall.

But the section in the back where water had been leaking undoubtedly showed deterioration, and when we started ripping it up it was nearly falling apart. That’s the big downside with laminate – it’s not as durable as some other options, and it doesn’t hold up well to prolonged exposure to moisture.

For our new floor, we decided to go with vinyl plank flooring (the interlocking variety that we got is called “luxury vinyl”). Vinyl flooring in general is a great option for vanlife because it’s durable and waterproof. Here’s what we liked about plank vinyl flooring:

  • You can find different thicknesses for increased durability
  • Luxury vinyl has interlocking edges like laminate, so installation is just as easy.
  • Installing luxury vinyl planks is much easier and more forgiving than laying down sheet vinyl.
  • It looks great, and often has a nice texture that makes it look more like wood (and stops dogs from sliding around – which was a BIG problem with our laminate flooring).
  • It’s waterproof and non-organic, so it will not mold or show water damage (or allow water to penetrate to the subfloor).

Downsides of Plank Vinyl Flooring

While plank vinyl has several advantages that led us to choose it for our new floor, there are also a few disadvantages to be aware of.

  • Contraction in cold weather. Vinyl planks are temperature sensitive, and they contract in cold weather. We’ve seen small gaps develop between our planks when we’re in lower temps. It doesn’t seem to affect the integrity of our floor, but we probably would have made a different choice if we had known about this ahead of time. Sheet vinyl would not have this issue, and our previous laminate floor did not contract.
  • Cost. Luxury vinyl planks are more expensive than both sheet vinyl and laminate. We paid about $60 in total for our laminate flooring, whereas the vinyl planks cost us about $180.

Installation was very similar to installing our original laminate floor.

We started  by the side door, and laid it down one complete run at a time. The vinyl planks locked together much easier than the laminate, and we used a rubber mallet to complete the final tap in.

We mixed up the lengths for each run. The first run we started with a full length piece, then started the second with a half piece, then a third piece, then another full piece, and so on. This staggers the seams, which makes the floor look more natural and hold together better.

Cutting vinyl planks is super easy with just a box cutter or a good pair of kitchen shears, which made it MUCH simpler to fit the flooring around obstructions like the wheel wells.

Finally, We Put all the Furniture Back In – and Voila!

completed floor

After we installed our brand new floor, all we had to do was put the furniture back in and reconnect the electrical – which didn’t end up being too bad since our furniture is largely modular.

We’re very happy with the new floor – it seems more durable, it looks a whole lot better, and the grayish tone that we went with breaks up the monotony of the wood color in our van.

Lessons Learned

  • Leaks and mold are serious business. It’s worth it to take the extra time to check for leaks and treat hidden areas with mold preventatives.
  • Make sure the furniture in your van is MODULAR – that way if you ever have to do something like this, it’s a whole lot easier to take things out and put them back in.
  • Vinyl plank flooring is better than laminate for van use. While it is more expensive, it’s waterproof, it’s more durable, it will not mold, and it often has a texture that prevents dogs from sliding around as much.
  • Vans are like houses – you’re always fixing or changing something!

Well, there you have it! Dismantling, mold treating, flooring, and reinstalling the furniture in our van took us about a week. Even though it was an unexpected problem, we learned a lot about mold prevention, and we were able to do a much better job with our flooring the second time around.

For more build guides, vanlife tips, and cute puppies, be sure to follow us on Instagram @gnomad_home and on Facebook. Cheers!