Dry rot in an RV is like cancer in a human body… it’s never good but not always fatal. It all depends on how far it’s spread before you find it. Maybe you can just repair the bad spots. Then again maybe the cancer has spread to far. The good thing is, dry rot damage can be repaired. The bad thing is it can cost a lot of money. Proper preventive maintenance and timely repairs are the key.
See the photo below.
I can tell you the only evidence of any problem with the trailer was at the front corner under the window. The rest of the trailer, inside and out, looked fine and in good condition. However, as you can see, only once repairs were started was the true extent of the damage visible. Don’t know for sure but it makes sense there is more damage under the sheet metal on the front wall as well.
The last I knew, the shop was still waiting to see if insurance was going to pay for the repair or salvage the trailer.