Welcome to the forum. I have found that Thor is usually very good about handling warranty and manufacturer related issues. I agree that waiting made it worse and they should have been contacted directly the first time. You are provided a concierge when you bought your coach and that's something that could have been remediated through them pretty quickly. Since it happened 3 times, make sure the sub floor isn't compromised as well. This issue may have grown due to the lack of immediate attention. Exposure to moisture multiple times may have exacerbated the issue. Just make sure you deal with Thor and they will fix it. AS others have said, taking it to the dealer should be fine. I am not sure taking it all the way back to the factory is necessary if you have a decent dealer to work with.
