Earlier this year my wife and I purchased a low mileage (15,000) 1999 Alpine Coach 40' FDS. Though the low mileage was a plus in many ways, the amount of disuse does have a downside. In our case the roof sat neglected for 16 years. Well, some work was done but poorly. A visual inspection can tell you a lot, but as I discovered not the whole story. When the coach was purchased, roof maintenance was a top priority. Here some of the things learned and the steps taken to restore the roof.
The Plan
My strategy was to work in stages and not to rush, knowing preparation is everything. Most of the time was spent simply preparing the surface for new sealant, tape and the final coating. That meant cleaning, cleaning and then clean some more. Experience told me when a surface is not clean and new sealant is applied, I would just be throwing money and time away, with nothing to show for the effort but a stiff back. Not taking chances with the weather, I only worked on one section at a time until complete.
First Cleaning
The first step was dealing with the black mold, algae and dirt. There are some expensive roof cleaners on the market however, I found Zep Mold Stain & Mildew Stain Remover ($7.00 gal) did a great job. Spray it on, let it sit, then wash it off. No exaggeration, it is that easy. Of course you will have to wash your entire coach afterwards. All that was washed off the roof will streak down the sides and on the windows.
Prep
The next step was indeed the hardest, most time consuming and one of the most important. Removing the old sealant. I was very thankful that my Alpine has a fiberglass roof. The hard surface does allow you to scrape without the worry of damaging a rubber membrane. No cutting corners here. I removed ALL the old sealant down to the bare fiberglass and cleaned multiple times with Isopropyl Alcohol. Of all the scraping type tools I had, an old dull steak knife worked well for getting the last stubborn bits off. Removing old sealant on the cooler days seemed easier because it was not as gooey. I was, however, surprised to notice the variation of sealant Western RV used. Some of the original sealant was well applied and extremely tough, certainly of high quality. Then in other areas the application was not as good and a different sealant used. Items like the on CB antenna, solar panels and plumbing vents, all original factory installed, but I could be wrong.
Lesson
Some areas had sealant added at some point in the past, but, what looked good on the surface was deceiving. As I began to remove the old stuff the truth was revealed. Water had found its way under because of poor preparation. The sealant was applied to a dirty surface. Rusty and loose screws showed that water indeed found its way in. Lesson, when buying an older coach plan on working on the roof. Go all in, do not merely add sealant, remove and replace all of it. In general, do not trust someone else's work. Otherwise, you could spend time chasing down leaks instead of enjoying your Alpine. I wanted to know for sure my roofs condition and have a known starting point.
Replace and Repair
In the case of plumbing vent covers, Fantastic vent covers and the refrigerator vent cover and flange, I removed and replaced all of them. All were weather worn, some were cracked and brittle. Obvious the refrigerator flange had leaked. In keeping with the "go all in" thinking, once the old sealant was removed, the covers were easy to replace. None are expensive to buy at any RV parts store. All hardware that came with the replacement items got thrown out. I used only stainless steel screws. While the covers were off and the Fantastic vents were accessible, I disassembled and cleaned each one and replace the cheap and noisy stool enclosure vent fan all together.
As a side note, I removed the original satellite dome, solar panels and bat wing antenna. The reason, I wanted a cleaner looking roofline, the satellite will not work in Alaska (dish too small) and the usefulness of the bat wing is long past. The bat wing did come in handy though. I cut off a piece of the wing and used it to bridge the mounting hole (a much larger hole than necessary cut in the roof at the factory) for the crank. Will install new solar panels at a later date.
Function Over Form
Once all surfaces where clean, it was time to apply new self-leveling sealant. I used Dicor self-leveling lap sealant (501 LSW). It was applied in sufficient quantity to fully cover where the flanges met the roof and each and every screw. As the sealant leveled, I applied an additional layer to cover any air pockets that showed up and any area I may have missed or where I wanted additional assurance of coverage. The goal was purely functional -- applying enough sealant to get the job done.
Overkill
Taking the advice from an iRV2 post, once the sealant set I apply EternaBond roof tape over all the Dicor. I believe the added protection over the Dicor will greatly extend the life of the sealant. And yes, all the surfaces and sealant the tape was to be applied to was cleaned with alcohol.
Holes Means Leaks
Putting holes in roofs is a bad idea. Every penetration in a roof has the potential of allowing water into places you do not want it. I was disappoint to see how many screw holes there were to simply hold down satellite and solar wires. When the time comes to install a new solar array no screws will be used. There are screwless mounting systems for ridged solar panels in addition to the flexible type panels that use adhesive. As far as securing wires, my plan is to use EternaBond tape.
Crack Repair
A project like this gets you up close and personal with your roof. The perfect time to keep an eye out for cracks. For Alpine owners, look close at the radius -- where the roof line curves down to meet the side walls. Obviously a stress point. As cracks were discovered, a little sealant was applied and taped over. Before any tape was applied, with a pair of scissors, I would cut/round the corners of the tape. The rounded edge will hold better and less likely to catch and curl up.
Trim and Molding
The next step was to remove the dried and discolored trim molding. The trim, an aluminum channel and screws, fastens the roof to the side walls of the coach. The molding fits over the aluminum trim to cover the screws and provides a finished look. Finding replacement molding was a little challenging. Local RV parts stores said that type of molding was no longer available, however I found it at Pacific RV Parts (
PRVParts.com: Motorhome Accessories & RV Parts Online) in California. After removing the molding, old sealant on the top edge of trim channel was removed. Then all the old screws were replaced with new stainless steel. I found that every screw was rusty and some heavily corroded. A dab of sealant was used on each screw before installing. At this point the molding was not installed until the roof coating was applied.
Seal or Not To Seal
I read a number of iRV2 posts on roof issues and maintenance and debated a long time as to the need to reseal/coat the entire roof surface because it was fiberglass. The decision came once the satellite dome and solar panels were removed revealing the protected roof area that preserved the original gelcoat. By way of comparison, it became obvious the original gel coat on the rest of the roof was gone exposing the fiberglass. So protection became a priority.
Using a very fine abrasive pad, you could use 200 grit sandpaper, the shiny areas that were under the satellite and solar panels were roughed up and the entire roof cleaned. Instead of using a high dollar pre-sealant cleaner and water, I opted to us Isopropyl Alcohol in a spray bottle and wiped down all the surfaces with clean towels. At this stage both my wife and I are working, she prepping/cleaning the roof and I was working the trim removing old sealant. We didn't want to deal with the water and then have to wait for the roof to dry.
An ordinary paint roller with handle was used to apply the coating. A pretty straight forward job, not really any different than residential painting, except easier -- no walls or ceilings for paint to sag or drip. The coating (Dicor RPFRC1 Fiberglass RV Roof Coating) was applied even over the roof tape down to the aluminum trim. The instructions recommend two coats, however it really takes three. The first two coats were applied in an afternoon. Held off doing a third coat for a couple of days due to overnight dew and cooler temperatures (highs in the 70s). It was obvious once applied, that the third coat did the trick, the color evened out indicating complete coverage. Used only two gals with a few ounces left over.
Home Stretch
Now it was time to go back to the trim. A bead of sealant (Dicor 551LSW) was applied in the top channel of the trim and then the final and last step. I installed the new cover molding. As the molding was installed, I pressed the top edge into the fresh sealant. Then with a rubber disposable glove on, ran a finger down the length of the sealant smoothing it out where the molding meets for roof surface.
Done!
A big job for sure. With a lot of elbow grease, good weather and a wonderful wife willing to roll up her sleeves and jump in to help, we now have a next to new roof! I did not keep close track of the total dollars spent, but I would say the cost for all the materials used was in the range of $600 to $700, including replacing all vent covers -- two plumbing, one refrigerator and three vent fan covers. Going forward with regular roof cleaning and inspections, I expect the investment in time and money to payoff for many years to come.
Tom, Patty, Hannah "The Big Dog" and Abby Kat, Indianapolis, Indiana 
All of the precautions, cleaning and prep were for not. If the Dicor sealant required a specific pre-treatment for good adhesion that was not at all clear in the product instructions. My advice is to steer a wide path around this product. Currently I am consulting with the folks a West Marine as what they use on boats that are exposed to much harsher environments.
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