Fiberglass Roof Bulge

BlueLine · 08-05-2011, 10:31 PM

During my last 2 roof wash and waxes I've noticed a small bulge approx 4" wide and 18-20" long on the forward section of the roof on the roof centerline just aft of the TracVision Dome. Since I first noticed this in the spring I checked all the sealing around the dome's mounting and all is in tact and good condition. I have no stains on the ceiling inside, and checked inside during some pretty heavy rains and no visable leaks detected. The area hasn't appeared to increase in size, and the fiberglss is not cracked, just slightly bulged in this one area. Is this roof cap bonded to anything underneath? Is there a fix? or should I leave it alone untill I have to set buckets around inside. The particulars for my Rv are in my signature.

Jackm · 08-05-2011, 11:33 PM

What year is your Adventurer and how high is the bulge? Does it seem like the roof is being pushed up at a single point or does the upward pressure seem to extend for the entire length of the bulge? You should be able to determine this by tapping on the area to see if the sound changes as you move from end to end. This will give you some clues as to what might be happening under the fiberglass. Fiberglass roofs are not generally bonded to the underlying substructure. As a result, an underlying structural "event" could have occurred which is now showing up as a narrow bulge on your roof.

Since no one likes to add one more opening in the roof, some folks would take a "wait and see" approach. On the other hand, some people might argue that you should find the underlying problem and fix it before it gets worse. Both viewpoints are legitimate so its ultimately up to you. If it were me, I'd call Winnebago and let them be the tie-breaker. In any case, keep us informed and best of luck.

Jack

BlueLine · 08-06-2011, 09:41 AM

Thanks for the response jackm. The coach is a 99, beyond any warranties. The bulge is raised about 3/8-1/2" and has a hollow sound when tapped. The bulge eminates from under the center of a SS mounting plate that the TracVision Ant. is mounted on. The installation is after market and looks professionally done and all the attachment points appear to be well bonded and sealed. My thoughts were maybe an over torque at one of the attachment points causing the bulge if the roof is not bonded to another surface such as the side walls are. I'm inclined to go with the wait and see unless someone puts the fear in me for immediate attention. I don't like disturbing the integrity of the mantle unless absolutely necessary, the TracVision installation would not have been my choice if it were mine originally.

Clay L · 08-06-2011, 10:50 AM

The roof is thin (1/16 inch?) fiberglass bonded to 1/8 inch or so thick luan. That in turn is bonded to polystyrene sheets about 4 inches thick. There is luan covered with the ceiling material bonded to the other side.

When the Feds started mandating the use of water based contact cements instead of the solvent based type I think the adhesive quailty was degraded.

I have a 20 by 20 inch or so area in the middle of my roof that will lift up a small amount - just enough to notice - when the weather gets hot and the sun is beating down on it. It will go back to normal when it cools down. It has done that for 6 years and has not gotten any bigger.
I am convinced it is not due to water intrusion.

BlueLine · 08-06-2011, 09:39 PM

Thanks Clay, after I posted my last post to Jack I began wondering if heat could be my problem. To my recollection I didn't have this problem untill the weather turned miserably hot, several days in the past month or so were tripple digits. Hope mine turns out to be like yours...I can live with that.

Five2o · 08-07-2011, 12:08 AM

I had a similar bubble on the roof of my Ellipse and Winnebago replaced the entire roof on warrante.

phredsee · 08-10-2011, 01:41 AM

If it were me, I would have a qualified Winnebago dealer look at it to be sure.

Short story, while traveling through Oregon this summer, very high winds caught the front drivers' side roof and lifted it front to back. The only thing holding the rest of the roof were the air horns and satellite dish. Ollinger/CW in Portland was able to repair and reseal it but the tech said this area was damaged before and the repair done at that time was probably inadequate (before I owned the coach).

Might be good insurance and piece of mind if it's nothing and might save you a lot more if it is. JMHO