Is it real hot out and or is the camper uneven ground? Sometimes when the TT is twisted the roof flexes a section can pop up that will return down once it is straightened out. Very high heat also some times aggravates the bubble with a twist in the TT. Mine has some ripples in the back corner. They come and go pending how the TT is setup and time of year.
Any idea on how high up the bubble is? A ˝” or 1 or 2”
Without seeing it (any chance of a picture?) it is hard to tell if it is just a level of normal or the beginning of a problem. My larger camper has 1/8 “ luan board then the bud board and EPDM. Some of the smaller TT’s only have the bud board and EPDM over the rafters. I have seen the pop up and down sections on both. The EPDM was not separated, it was just flexed up by the backing and when it cooled down, it went down too.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
Google Custom Search For Sunline Owners Club