Hidden mold does not make for a happy camper!
I bought this 2007 Fleetwood Mallard camper in early May for what I had thought was a great deal, excited for a project that would be mostly cosmetic. The same day I picked it up, I went to JoAnn Fabrics (R.I.P.) and grabbed some beautiful, heavily discounted fabric to reupholster the dinette cushions. The next morning I measured the mattress for a replacement and browsed peel-and-stick backsplash online. I figured that after a weekend or two of cleaning, painting, and sewing, and I’d get to enjoy the camper all summer.
1. Before: Ignorance is bliss.
Then, I discovered a soft spot in the wall under the dinette window and my curiosity dictated that I had to open it up. I assumed it was water damage and that I would just have to replace the lauan plywood and seal it back up. Sadly, I found much more than I’d literally bargained for…
2. Under the window by the dinette, the plywood was dark and moldy.
The first peel of wallpaper revealed dark, damp plywood with mold growing in circular patterns—almost beautiful, if it wasn’t inside my camper. This was the moment I decided to wear a mask and dig out my stash of COVID-era N95s. I then opened the walls under two other windows and found various stages of mold and rot. When I opened an upper corner at the roof and found missing wood framing, I realized this had become much more than an easy weekend project.
3. Left: It was shocking to see how much framing was just gone. This is after removing only the lauan (thin plywood walls) but not any framing—this was all the work of water. Right: Rebuilt!
I headed to the local lumber store for lauan, 2x2s, and insulation. My initial plan was to rip out the rotten framing, replace it, reinsulate, close it up, and maybe reseal the roof. But every technical resource I found insisted that if the roof membrane is flaking or revealing black rubber (both true for my camper), it needs full replacement—not just resealing. I had to decide: put a Band-Aid on it, or go all in?
I work with a team of building scientists—obviously, I went all in.
My dad was flying out to Wyoming to drive my brother’s car back to New Hampshire, and I invited him to “visit” me for a few days first. Together we began removing the roof trim and discovered just how rotten the wood frame was when screws refused to back out. We took off the corrugated aluminum panels at the front to replace the framing from the outside and add a proper drainage layer (Weather Resistant Barrier, or WRB) beneath the cladding panels.
Are you surprised the panels were installed directly over the framing with no WRB?
I was, but shouldn’t have been. As it turns out, the construction of campers and other RVs isn’t governed by the same codes and standards used for stationary buildings. The National Fire Protection Association 1192 Standard on Recreational Vehicles (NFPA 1192 Standard) applies to RVs like my camper, but even after decades of mold-related consumer complaints, the standard still doesn’t address basic weatherproofing (the ANSI A119.5 Park Model RV Standard is much more robust and has included wall WRB requirements since 2003, but that standard is for larger RVs intended for longer-term but still temporary living).
4. I overlapped the upper WRB sheet over the bottom by about a foot, and left enough material at the top to tuck it under the new TPO roof.
Next came the roof replacement. I bought a roll of camper thermoplastic polyolefin (TPO), adhesive, and lap sealant for about $550 and spent 16 hours removing the old roof, pulling staples, laying new lauan, and gluing down the membrane.
5. The roof has been the most time-consuming part of the renovation by far. The lauan is only 1/8 inch thick, so we couldn’t move around on it without a piece of plywood to disperse our weight. I later stapled a towel to the bottom so I wouldn’t damage the new TPO while dragging the plywood around.
After successfully weatherizing the camper, progress since then has been slow. It was summer—and when it’s 85 and sunny, I’d always rather bike, float, camp, hike, or boat than bake on top of a camper pulling staples from rotten wood. I’ll report back in the spring for some satisfying “after” photos!
To-Do List (Going “All In”):
Exterior
1. Replace rotten structural framing
2. Remove front panels, add WRB, reinstall panels
3. Replace roof (lauan and TPO membrane); reinstall vents/openings
4. Re-trim with new butyl tape, screws, weather-strip
Interior
5. Reframe windows
6. Reinsulate with fiberglass batts
7. Uninstall windows
8. Install new lauan panels; mark for electrical and table mounts
9. Router smooth window openings
10. Reinstall windows with new mortite (rope caulking)
11. Complete interior taping, caulking, trim
12. Paint*
13. Reupholster cushions, build new couch frame, install new mattresses*
* These are the only tasks I thought I signed up for when I bought the camper.
Some questions I’ve fielded from friends, family, and acquaintances:
Why not just reseal the roof?
The severity of the rot in the front corners made me concerned about rot in the structural roof members and framing. And everything I read said resealing was not the solution.
Why not just caulk the windows?
As soon as that fails, water will find its way back inside and get my new insulation and lauan wet. The existing mortite/caulking cord is dried, cracked, and failed.
Why did you open the walls in the first place?
I couldn’t help myself. Turns out, ignorance is not bliss!
Conclusion
In the end, this whole project reminded me that buildings—whether homes, multifamily projects, or aging campers on wheels—live or die by how well they manage water and allow assemblies to dry. Durable construction doesn’t happen by accident; it comes from intentional control layers, protected transitions, and design for worst-case weather. My camper may not be a high-performance building, but for me, fixing its failures has reinforced how essential good water management and thoughtful design really are. It proves the principle we share with clients every day: building it right the first time is cheaper than making repairs in the future.
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