I think that all early 17' Bigfoot trailers have the same problem even if they never saw snow. It's due to poor design that was fixed in later years. Mine is the same way and I've chosen to ignore it for now. The fix would involve stripping the ceiling and upper walls and inserting bracing under the figerglass that would re-arc the roof. Then rebuilding the interior and hope that the lower walls would hold the extra pressure. Mine doesn't leak and few people will see the rooftop of the 7' high trailer. So I live with it.