Hi and welcome
What year and model Solaris do you have?
On the newer models that used EPDM rubber roofing material, Sunline used a product they called Bud Board. It is heavy compressed fiber board.
It is not cardboard like you think of in corrugate boxes that you buy just about everything in the store that comes in a cardboard box, it is more of an industrial fiber board that is made from I believe a paper type product. So one might nick name it cardboard but it is really not.
See this post it has actual picture of it. http://www.sunlineclub.com/forums/ph...pic.php?t=1666
Sunline bonded the EPDM to the bud board and then pending year and model we believe there is 1/8" thick Luan board under it that then lies on the rafters. That practice however seems to be model specific. On some smaller campers the bud board seems like it is right over the rafters and no luan board. On campers that had the walk on roof option, don’t know if the bud board is there or not. Have not had anyone with a walk on roof report back the makeup if they pulled a vent or something else out.
We have not heard of a large problem from using the Bud board. Actually we have not had any one report a problem with the bud board itself.
However, bud board, plywood, or luan board, if you get a tear in the rubber or sealant cracks/leaks around roof penetrations, it is not good. The fiberglass insulation gets soggy, the wood rafters get wet, the ceiling inside gets wet and yes the bud board does too but that is the least of your issues when you have a leak.
Don’t know where you heard about the card board as I have heard it by some dealers selling used campers too, but they never gave me anything specific on if it ever causing an issue with it’s use. This seems to be more of an out of context rumor/urban legend as you called it.
I myself would not tear off a perfectly good non leaking roof to replace the bud board. Again think of it like this, if you bonded the EPDM to plywood and you have a leak, the plywood rots too so there is not a lot of difference once you get a leak. Some of us “think” Sunline did this as a method to reduce weight but really do not know the actual reason.
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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