I use 2 ft x 4 ft x 1/2" sheets of plywood. Large enough to spread the load out over the 16" center rafters and small enough to be able to lift up there.
You can use 3/8 thick, 1/2" 5/8 or 3/4 but 3/4 may be a bit to lift. If your sheets are larger, that is OK too. The 4 foot long seems to be the right size to span enough rafters to help spread the load. 3 foot long would about miss a 3rd rafter but just make it.
After washing the roof, yes look at all caulking for sure. That is the time to touch up any tiny hair line splits or cracks in the caulking. You use the Dicor caulk that I showed in the link above in the last reply.
And after the caulk has dried then apply a UV treatment to the rubber, the caulk and all the plastic on the roof which is a lot. I also put this on the plastic and decals on the camper sides. I use 303 Aerospace protectant. This stuff https://www.goldeagle.com/product/30...ace-protectant
This treatment over a long time makes a significant difference in helping keep the sun from cooking the life out of anything rubber or plastic.
I spray it on, then use a soft rag mop head on a pole and reach from the edge to spread it all over. This is supposed to be a car wax applicator but I bought it to use on the roof and reach in.
Ideally you wash the roof, check the caulking and apply the UV protector 4 times a year. Yes I know that sounds like a lot. It will allow the camper have a longer life if you do. Bare minimum would be 2 times a year and that may be pushing it.
1. The fall going into winter storage outside is critical as you do not want any splits in the sealants going into winter.
2. Just coming out of winter in the spring is also critical to catch any splits in the sealants just started coming out of winter.
3 & 4. Then spread across the camping season in the warmer weather months.
If you have a barn to keep the camper in all the time, this greatly helps and you can reduce some of the washing's. But not all of us have a barn to do this. My camper lived outside for 10 years before the barn came big enough to put the camper in. That was a long wait... but worth it when it came. Some use covers over the camper in the winter when the camper is outside, and these do help. They are a bit to put on and take off but they really help keep the elements from attacking the camper.
As FYI here are the Dicor instructions (the mfg who makes the rubber roof) on maintaining your roof.
And here are some videos they have on roof care.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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