I received an e-mail from my wifes #1 son Mark describing how the
paneling around the front window of his class C motorhome had pulled
away from the window frame and the wood underneath was soft and
crumbly. He said the best way he could describe it was that it looked
like termites had gotten in but he just couldn't imagine termites in a
motorhome! What did I think?
Of course I knew what the problem was and wrote back to say he had dry
rot. To make things worse, they had just purchased the motorhome last
spring and no doubt the dry rot was an existing problem. It would have
been nice to have spotted it before he closed the deal.
The term "dry rot" is actually a misnomer because the decay is caused
by certain fungi capable of carrying water into the wood they infest.
The water can be transported far away from the source and the wood will
often feel dry to the touch thus the term dry rot.
Gradually, the wood decomposes and its strength is lost. And, as Mark
knows too well, such damage is often inconspicuous until it's final
stages, working behind the paneling on the structural framing of the RV.
Dry rot in an RV can be caused by an undiscovered plumbing leak but is
usually caused by a leak in the outer skin which lets rain water in.
And that's about all I knew about dry rot when I received Mark's e-mail. But it got me wondering.
I couldn't find much information on the internet about dry rot in RVs
so I drove over to All-Rite RV Parts and Service in Yuba City,
California. If I can't fix it myself Dave Allred and Dave Stewart are
the guys I call. Here's what they told me.
Almost everyone is good about recaulking the roof seams but that's only
part of prevention. Cracks can develop in the rim of plastic roof vents
well above the seam. Dave said he's seen it often enough that he
recommends replacing plastic vents with metal ones.
Marker lights are often the source of a leak. Make sure you at least
check them each time your reseal the roof. And be sure you replace any
broken or missing lenses.
Windows are a major source of water leaks. Especially the front
overhang window on class Cs. Partly because they get the full force of
rain while driving but mostly because they are too hard for most people
to inspect. Or too easy to neglect. Dave advised those of us with RVs
over ten years old to have all the windows removed and resealed.
INSPECT YOUR RV REGULARLY On the outside, look for irregularities around window and door frames.
If you have screws that won't stay tight you may have a problem. If the
screws are rusted or corroded you DO have a problem and it's a good
indication of dry rot.
A day or two after you've washed your RV or after a rain storm check
along the bottom edges. If it is still wet you probably have a leak.
Check it out.
On the inside, look for water marks on the ceiling especially around
roof vents. Remove the vent flanges and air conditioner shrouds and
look for discoloration in the wood. That's a sure sign of a leak and
possible dry rot.
And, of course, check around the windows. Look for discoloration, softness of the paneling and loose screws.
GET IT FIXED! Repairing the leak is only part of the repair. You must make sure the
wood is dry. If there is any sign of dry rot treat the wood with an
antfungal solution. Dave says regular household bleach works for him
but there are commercial formulas of disodium octaborate tetrahydrate
or sodium borate with brand names of Bora-CareŽ, GuardianŽ, JectaŽ,
If the wood has decomposed enough that the screws won't hold, don't
just put in longer screws! Dave and Dave said Git Rot, an epoxy like
product, can rebuild dry rotted wood, but if you wait until the long
screws won't hold there may not be enough wood left to rebuild.
No doubt dry rot is responsible for the early death of many RVs simply
because it isn't spotted and repaired before it gets out of hand. Your
RV doesn't have to be one them.
The repairs to Mark's RV wound up costing him $7,000! The good news is
his motorhome is nearly as good as new and has many more miles left to