A discouraging thread in an RV forum seems to show that plenty of truck camper owners have found rot or dry rot in their camper. The small number who claim they don't have rot issues say they bought their TCs new, and took scrupulous care to see to it that water was kept out of their rigs. However, a huge majority of those writing on the thread said they've dealt with rot issues, to the point one visitor noted, 'There are two types of camper: One has rot. The other has rot, but it just hasn't been discovered.'
After a bit of head scratching, of the four truck campers we've owned over the decades, we've had varying amounts of rot in three. Perhaps we just didn't discover it in the one. In one, a musty-mildew smell in the cab over finally drove us to pulling up the bed planking. Sure enough, underneath we found the need to replace the entire support structure--not a lot of fun, and certainly a financial disaster if we had to hire the job out.
How can you do to protect yourself when you're shopping the used camper market? The old rules that apply to all RVs apply. First, open all ceiling level cabinets--look for water stains. If you see them, you can pretty well guarantee rot-osis.
Run your eyeball down the siding, warps and buckles should be points of suspicion. One area where many camper owners say they find rot problems is in the "wing" area--the outer wall at the rear of the rig where both sides of the wall are exposed to the elements. Our photo shows an area rot in a wing near a corner jack. Someone tried to "putty over" the problem, but it's sure no cure. Other areas of complaint include around rear door sills. Poking a bit with the tip of a knife will often reveal issues. If the tip goes in without pushing hard, there are problems lurking.
It's a tough job to cure dry rot. If the area is small, sometimes an injection of dry-rot cure potions sold on the boat repair market will help. But if you hit the level of taking off siding or roofing, be prepared for a lot of work, or a huge expense. Shop carefully!
photo: R&T DeMaris