RV Repair: Roof of pop up trailer, roof surface, water damage

Question
On the top of my pop up trailer there is a blister, on the out side top, that has appeared. The roof also seems to be sagging in the middle. How do I fix it so the blisters on the top disappear and the roof is not sagging. Are they related?

Answer
If I get this you have bubbles and a sag but not in the same place . Now that being said you more than likely have a water prob its getting in somewhere and causing the top to delaminate from the bottom or lower roof surface. There isnt much to do beside try to dry it out and then repair the water damage and restick the cover on the top



If I am way off let me know maybe send some pic and I can tell u more