Roof puffed up while traveling.

[cwalther1]

Recently had a full top - bottom detail done on my Hill Country HCT32RL. Guy caulked compete roofline with DAP AMP. Also washed complete unit and roof, looks new again ! On the way home, I noticed in my rear view mirror that where the front cap meets the roofline, there was a small section on both sides where air is getting under the roof and it is puffing up. Crawled up there and I do not see any spots where air could get in there. Could it be coming from somewhere further back, like around front a/c unit ? Caulking looks good, roof has no tears. All seals appear solid. Any ideas?

[660catman]

It’s not so much that air is getting in as the air flowing over the camper actually pulls up on the roof. I’ve seen many a camper with the infamous roof bubble travelling down the road. Roof is still attached across the front.

[Lloyd]

Originally Posted by cwalther1

Recently had a full top - bottom detail done on my Hill Country HCT32RL. Guy caulked compete roofline with DAP AMP. Also washed complete unit and roof, looks new again ! On the way home, I noticed in my rear view mirror that where the front cap meets the roofline, there was a small section on both sides where air is getting under the roof and it is puffing up. Crawled up there and I do not see any spots where air could get in there. Could it be coming from somewhere further back, like around front a/c unit ? Caulking looks good, roof has no tears. All seals appear solid. Any ideas?

Years ago they had that problem. (membrane getting air under it) At that time it was decided where the front cap and the membrane meet, the membrane wasn't tucked under that front cap and secured good enough. Consequently, air would get in there and the roof membrane would balloon. Sometimes even tearing off the roof. Everybody, including myself bought a roll of Eternabond tape. (4 in.) We cleaned the area the tape was to cover real good and lapped the tape half over the front cap, and half over the membrane. You have to clean it good and roll the tape down straight with no ripples or gaps. Once this is done correctly you shouldn't have to worry about the roof tearing off because of air getting in there.

Some even went so far as to apply the tape in the same manner on the rear of roof also.
I have also seen where some of the guys by passed the caulking and applied the Eternabond tape all the way around on the roof edges, and every place there was a roof intrusion. I never got that ambitious.

[BranComew]

The roofing material itself may not be adhered properly in some areas. if the adhesive has weakened over time or during the detailing process (like washing or exposure to heat), air could get under the membrane while driving, causing it to lift or puff up. While the front cap area is where you notice the puffing, the issue might stem from a vent, skylight, or air conditioning unit further back. Air traveling at highway speeds could be getting under the roof material near these locations and moving forward to where the roofline meets the cap. Make sure the seals around your AC unit, roof vents, and other fixtures are intact and tightly secured. In any roofing job, check the edge trim where the roof membrane attaches to the sides of the RV. If this trim is loose or the screws have worked themselves out, air can sneak in underneath the membrane and cause it to lift. Tighten any loose screws and ensure the molding is pressing firmly against the roof.