New Roof – New Solar Part 1
We recently pulled the old, burned-out flexible solar panels off the roof of our Winnebago Outlook. What we also found was a 15-year-old fiberglass roof that had seen better days – and not much care over the years. It was time to change that.
One of the great things about fiberglass roofs is their longevity. With a little routine maintenance, they can easily outlast other roof types. Our Winnebago has spent all those years baking under the Texas and New Mexico sun. Amazingly, it never leaked or gave us any real trouble. But a closer inspection revealed the truth: the roof needed serious attention.
Before installing our new Renogy Shadow-Flux panels, we decided the roof had to come first. That meant a lot of prep work: cleaning and sanding, finding and fixing cracks in the silicone, removing the old satellite dish and TV antenna, repairing small delamination spots, addressing stress cracks, cleaning again (and again), sanding everything smooth, and finally – repainting.
During the process, we uncovered several problem areas where cracked silicone had let moisture sneak in. The most concerning spots were along the joint between the front cap and the roof. That led to some minor sidewall delamination on the cab-over, plus a small area on the roof itself where the fiberglass sheet had pulled away from the structure beneath.
Thankfully, living in a mostly dry climate worked in our favor – the damaged sections were limited to just a few inches. To fix it, we drilled a 1 inch hole into the center of the delaminated area, then injected marine-grade adhesive, spreading it evenly underneath with the help of a stick. For extra security, we fastened the section with coarse screws coated in adhesive.
The holes left behind from removing the satellite dish and TV antenna needed careful attention. Each one was filled with marine-grade adhesive, sealed with an aluminum plate, fastened securely with screws, and then topped off with Eternabond tape for extra protection.
Throughout the process, we cleaned the roof multiple times to strip away any oily or waxy residue. A spotless surface was crucial to ensure proper adhesion for the paint later on. The (almost) final prep step was sanding. We used 80-grit paper on a handheld orbital sander for the large areas and good old-fashioned sandpaper for the corners, edges, and all the nooks and crannies. Unfortunately, this meant evicting a few critters who had taken up residence on our roof – but that couldn’t be avoided.
Once the sanding was done, it was time for another deep wash to remove every trace of dust. Only then could we move forward with the installation of the solar panel rails. Since we planned to glue the rails directly to the fiberglass, we decided to install them before painting. That way, the adhesive would bond to the original roof surface, not just the new paint layer. It took another full day, but the rails went on solidly and exactly where we wanted them (see part 2 of the blog post).
Finally, it was painting time. After a lot of research, we chose to go the traditional route with Rust-Oleum Topside, a durable, UV-resistant marine coating. Because we were working in the middle of summer, we thinned the paint with mineral spirits as recommended in Rust-Oleum’s technical guide. Using rollers for the wide, flat sections and brushes for the detail work, we applied the first coat and let it cure for about 28 hours.
The next day, we rolled on the second coat. Then came the hardest part – waiting. We gave the roof several days to fully cure and harden before even thinking about reinstalling the solar panels.
The result? A roof that looks almost brand new, tougher than ever, and ready to overs us into the next stretch of adventures.
Links to the old flexible solar installation blog:
Installing flexible panels with Eternabond
Installing flexible panels with an air gap
Unfortunately, our flexible solar panels didn’t hold up very well. Some panels were completely dead and others were not producing anything close to the rated output after just about 5 years. That is disappointing, but also in line what others experienced.
Michaela Merz is an entrepreneur and first generation hacker. Her career started even before the Internet was available. She invented and developed a number of technologies now considered to be standard in modern web-environments. She is a software engineer, a Wilderness Rescue volunteer, an Advanced Emergency Medical Technician, a FAA Part 61 (PPL , IFR) , Part 107 certified UAS pilot and a licensed ham . More about Michaela ..