Keep inspecting as others mentioned and resealing. Not sure where you are gonna buy your trailer at, but if you buy it from CW, they give you an Elite membership. As part of that membership, you get a free inspection of your unit every year while your an Elite member (3 years). We had them do the free check this spring on our Class C. They located a small hole in the roof and sealed it. Not sure when or how it got there. Was never seen before. But there was no damage from it. They also checked all the other seals and other components. While it's good to keep an eye on it yourself, it doesn't hurt to have another set of eyes or two looking at it as well. I don't think you have as many issues of delam with the newer units as you did with the older ones. But can still happen...