Friday, November 11, 2005
DRY ROT
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. 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.
Almost everyone is good about recaulking the roof seams but that's only part of prevention. Cracks can develop in the base of plastic roof vents well above the seam.
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 C's. Partly because they get the full force of rain while driving but mostly because they are too hard for most people to inspect.
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.
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 sign of a leak and possible dry rot.
And check around the windows. Look for discoloration, softness of the paneling and loose screws.
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. Regular household bleach works but there are commercial formulas of disodium octaborate tetrahydrate or sodium borate with brand names of Bora-Care, Guardian, Jecta, Shell-Guard or Tim-bor.
If the wood has decomposed enough that the screws won't hold, don't just put in longer screws! 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.
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.
Almost everyone is good about recaulking the roof seams but that's only part of prevention. Cracks can develop in the base of plastic roof vents well above the seam.
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 C's. Partly because they get the full force of rain while driving but mostly because they are too hard for most people to inspect.
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.
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 sign of a leak and possible dry rot.
And check around the windows. Look for discoloration, softness of the paneling and loose screws.
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. Regular household bleach works but there are commercial formulas of disodium octaborate tetrahydrate or sodium borate with brand names of Bora-Care, Guardian, Jecta, Shell-Guard or Tim-bor.
If the wood has decomposed enough that the screws won't hold, don't just put in longer screws! 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.
