The roof plywood on my 2005 26.5RB is thinner than the plywood in the floors. What is the reason for the thinner plywood in the roof.
Off the top of my head - it would seem like thicker plywood would create more stability.
Evidently, LD didn't feel it was necessary. Thicker-than-needed plywood adds weight in the worst possible area, up high, raising the center of gravity.
I have been on our roof hundreds of times, loading and unloading our seal kayaks, as well as working on things. The roofing joists can be felt when walking up there, I mark each joist by putting a piece of 3M Safety-Walk tape on the spots to step when walking on the roof. This takes a lot of stress off the plywood.
Amazon.com: 3M Safety-Walk Slip Resistant Tape, 2 in x 15 ft, Anti Slip... (https://www.amazon.com/3M-0051131790797-Safety-Walk-Tread/dp/B0006HVKM4?th=1)
(https://live.staticflickr.com/1154/1416467930_f070140db5_z.jpg)
Larry
Larry -- That's a genius idea. I am also one of those people who avoids crawling (or, walking) on the roof at all costs. This is a much safer way to do so . . . if necessary.