2005 Fleetwood Pioneer 18T6 - water damaged sub floor

I had the exact same model I bought new in 2007 and had it for 3 years. One problem was the drain pipe broke right above the grey tank due to storage under the bed hitting it. After the repair, I made a wood compartment that would cover the pipe so it would not get hit again. Also water entered from the tires kicking it up. I took sheet aluminum to put over where the water hit. Let air get to everything to dry out fully then coat the wood with Git Rot. That stuff works great at making the wood stronger. Just follow directions and you will like the results. Best of luck. We enjoyed ours for 3 years. Its a very nice layout and great for up to 5 people (one on the sofa)