front cap to roof joint
Also in the Pacific Northwest. Last spring, I had a small leak in my 2003 Horizon, front cabinet over entry door.
Couldn't find a leak, but had some time between rain showers in May, and decided the joint hadn't been caulked in a long time. So I got the right 3M caulk, and scraped the old joint as clean as I could. What was not visible, was an air gap right behind one section of the caulking. It looked very tight, but after I scraped some, I was able to pull out a 3 foot long piece of caulk, that was not sticking to the top and bottom of the joint.
When water was running down the roof, from back to front, and the temperature was cold enough, the joint must have opened just enough to let some water through.
The tape method would have been the easiest fix, but I decided to follow winnebago's instructions and do it their way. No leaks in following rain storms, so the system works. But not something I would want to tackle in winter.
Now we have a new rig, and boy has it rained lately!
I really hate leaks.
Dan & Barb
2010 JourneyExpress 39n