My Motorhome is an older 1990 34 feet long with no slides. It has an Alpha Systems rubber membrane roof. The rubber roof was getting old, it had a few leaks and a few small rips in it, it was exposed to 20years of hot CA sun, it was chalking off and every time it rained more of it chalked off sending large ugly streaks down the side of the motorhome. I felt it was totally necessary to recover it.
The first thing I did was take the 2 AC housings and the fridge cover off, I didn't take the ACs off like some people do, just the covers. I also removed the TV antenna, I purchased a new digital one that I haven't put on yet.
Next, I pressure washed it with my pressure washer hooked up to my garden hose turned on full blast. The next day I pressure washed it again to make sure I got all the dirt off, then I let it dry 24hrs. Next, I had to scrape off the putty that was around the 2 air vents, 2 waste water tank vents, the luggage rack/latter, the fridge vent, the TV antenna mount and the radio antenna mount. I also had to scrape off the silicon that was put on from a previous repair job. I let the thing sit in the hot summer sun all morning and the putty got soft and was easy to scrape off with a putty knife and a wire brush, the silicon was harder to get off. I also had a few bubbles in my rubber roof that I had to cut with a razor blade, I put some liquid nails under the cut flaps to make it nice and flat and let dry for 6 hours. My rubber roof has a bit of a dome shape, not a flat roof like most newer RV roofs, so put some spare painter's tape I had lying around the garage along the side edges of the motorhome.
Next I put on flexible bond tape around all the vents, both antennas, and at the front and back where the rubber connected to the front cap and in the back where it ended along the back edge. I put it around the luggage rack tubes and I also used tape on all the rips and where I had to fix the bubbles. I cut the 3" tape in half using 1 1/2" strips where possible and used 3" where needed.
The next step was to put on primer, I mixed my flex primer and covered the entire roof including the tape using a paint roller and a paint brush. It only took 1 1/2 gallons of primer to cover the whole thing. I let the primer dry for 48 hours.
Next I used Liquid Rubber (5 gallon tub). I mixed it up with a mixer attached to an electric drill moving it around the tub for 15 mins. I then covered the entire roof with the liquid rubber. I put it on in 3 coats waiting 24hrs after each coat. I coated it around the AC units as best as I could with a paint brush. I also used a paint brush to put it around all the vents including the 2 waste water tank vents, over the antennas mounts and along the sides and anywhere I had tape. I used a roller to cover the entire roof. After the 3rd coat I let it dry for 48 hrs. I cut the painter's tape off the sides with a razor blade and then used a paint brush to apply a thin coat of liquid rubber along the sides where I had cut off the painter's tape to get a good seal to the metal piece that runs along the edges. I used about 4 Gallons of Liquid Rubber to do the job. I have 1 gallon left over for touch ups or future repairs if needed. I next put the vent covers back on. I painted the housing of the fridge cover with white spray paint I already had. I pressure washed the AC housings and put them back on when they were dry.
Done! It looks great. It should last 25 more years!!
Here is a list of things I had to buy. I did all the labor myself, it wasn't very difficult. The hardest part was scraping off the putty sealer and the silicon. Putting the primer and the liquid rubber on only took about 40 mins per coat.
F1501/2 Proflex Primer 2 Gallon Kit--cost $159.99--> F1501 2 ProFlex Primer 2 Gallon Kit | eBay
Liquid Rubber Smooth Sealant 5 Gallon Tub (white)--Cost $239.99 + $65 shipping and hazardous matierials charge = $304.99--> Liquid Rubber Smooth Sealant â€“ Liquid Rubber Online Store
Eternabond RoofSeal Black 3" x 50'--Cost $44.88---> Eternabond RoofSeal Black 3" x 50' - Roof Flashing - Amazon.com
Liquid Nails from Home Depot--cost $2.98 + $.22 tax = $3.20--> Liquid Nails 10 oz. Heavy Duty Construction Adhesive-LN-903 at The Home Depot
5 gallon mixer from ebay--cost $6.50 + $3.29 shipping = $9.79---> http://www.ebay.com/itm/5-GALLON-DRI...vip=true&rt=nc
Paint roller/tray and 2 cheap paint brushes from my local hardware store--cost $12 + .90 tax = $12.90
Total Cost $535.75
I just finished it 3 days ago. I haven't taken any pictures of the finished roof yet but I can post some later if you want to see.