[BusNit]

I've since repaired another rotted section of steel on the water heater side of the bay. Same deal as the left side. Rotted steel concealed by the foam. I believe water ingress was from ill drilled holes through the fiberglass that were never sealed. Once water gets in there, it has nowhere to go until it eats itself out. The aluminum bottom trim was all corroded. I had a shop replicate the bends and drill the holes to match the original pieces. New sections were fabricated out of 16ga galvanized steel. I test fitted them and sent them off to powder coating for now. They will be silver which will not match the coach paintwork until a final respray happens in the future. What I discovered on the water heater side was the original drain was cut open too large in the fiberglass and the silicone had failed allowing water to seep in between the wood and steel. I found a larger commercial sink drain that fit the hole perfectly. (Zurn 3" utility drain) Underside is sealed and lined with polyiso foam board with all edges sealed again as I did on the other side.