My 2014 Scamp
and my previous 91 Scamp
both have OSB floors sealed on both sides with fiberglass resin. The 91 (stored outside at a remote lot) had leaking windows
before I realized it.
Floor rot almost always results from window or plumbing leaks
, not from road spray, etc. In fact when looking under my 15 year old 1991 the OSB looked quite clean and fresh. Plumbing leaks
are the rarer cause and quickly make themselves known before much damage can happen. Window leaks
are more serious and often are hidden for months or years. Over time the window seals dry out, shrink in the sun, and lose their flexibility over the years. The difference in expansion between aluminum and fiberglass must make seals prone to leaking too as the trailer heats up and cools down daily, especially if stored outdoors. Add in road vibration and 60 mph wind driven rain and they ALWAYS end up leaking eventually. These leaks
can go unnoticed for some time as the water often weeps down behind the bubblewrap insulation. I check the window seals carefully every year if not more often and probably will take the windows
out and reinstall with fresh butyl tape every 5 years. Reinstalls are a hassle but much easier than replacing floors. Quality houses have overhanging eaves to prevent water from flowing down the siding and windows
. Our FGRVs don't and might look a bit silly if they did. So the quality of the window seals is very important.
I am not confident there is any foolproof test to determine if a window is leaking, but close examination will help. Maybe even snugging up the screws that hold the windows every couple of years in is a good idea. Maybe turning the fantastic fan on full, blowing in, and closing all the windows and vents would create enough internal pressure to make soapy water sprayed on the window seals bubble up. Works well on propane
Also window leaks
are common on any older RV regardless of manufacturer. FGRV are just much more durable and suffer less. That's why 20 year old stick built RVs are so rare.
Hopefully other folks have ideas on this.
PS. I had always assumed Scamp
bedded their aluminum windows in butyl rubber, but when I look closely at my 2014 all I can see is a bead of what seems like silicone rubber doing the sealing. OTOH the butyl rubber was evident on my 1991. Does anyone know how they do it under the silicone rubber where I cannot see? As others have pointed out silicone is not a good material match for fiberglass.