A leaking skoolie roof is no good especially if you've already invested the time and money into a school bus conversion.
~ Written By: Brock Butterfield ~
For this tips and advice article I'd like to share my experience as well as a few other's experiences on how to prevent water leaks in your skoolie roof from molding or ruining all the work you've put into your school bus conversion. I'll recommend a few products that have been tried and tested by either myself or other skoolies and discuss what common products to avoid if possible.
Step One: Preparing the school bus roof for leak prevention.
You will find a pretty common factor among most school buses with the white roofs. Almost all have the little black dots caused from oxidation. With my first school bus conversion I thought that those little black dots and specs were from a tree dripping sap. I simply used an automotive wash brush to scrub the roof and prepare for paint. I learned later that this was an epic mistake. This little black dots didn't really come off during the scrubbing so I assumed they weren't going anywhere but after time they were able to loosen up causing my paint on the roof to chip and flake away.
To properly prepare for paint or elastomeric paint (which I'll talk about in the following step) you'll need to get out the sandpaper and get rid of any residue that's on the roof. For this task I like to use a sanding pole, 120 grit sandpaper and then my automotive brush with the hose attachment to clean it up.
Step Two: Using the proper caulk on your seams and vents.
I'll refrain from my normal joke making of how everyone likes good caulk to save you some reading time. It's important to mention here that I would at all cost avoid silicone for this part of the job. I used it on my first skoolie and regretted it. I've working in construction since 94 so I'm no newbie to using good product but my guess is that the constant change in heat and cold on metal along with a moving and vibrating vehicle caused the silicone to fail. I began to experience leaks not more than one year after applying silicone to everything. Seams, rivets, around marker lights and vents.
In speaking with other skoolies and dipping into the RV world of repairs I learned about Dicor's 501LSW-1 Lap Sealant. It's got a nice self leveling feature so all you have to do is run it through the caulk gun and let it settle. I like to go overboard however and put on a pair of latex gloves and really smear it around to make sure all seams, rivets, screws, vents and marker lights are completely dialed. Let it cure and dry in the sun or a warm and dry shop for at least 24 hours. It'll be ready for the next step once it's no longer tacky to touch.
Step Three: Using the proper roof coating
After you've finished playing with your caulk (last caulk joke I swear) you're ready to move onto school bus conversion roof sealant. This will be the saving grace of preventing a roof leak on your school bus roof. There are two main roof coatings that skoolies, RV owners and van lifers seem to approve of. The first is Henry's Enviro-White Roof Coating which goes on like frosting and settles into one giant membrane of elastomeric and quoting from their website here is what it has to offer:
Henry® 687 100% Acrylic Enviro-White™ Extreme Elastomeric Roof Coating is a premium, high solids white reflective roof coating. It features Dirt Pick-Up Resistance (DPR) technology, which prevents dirt and dust buildup, keeping the roof whiter and more reflective longer. When cured, it forms a permeable membrane, which prevents liquid infiltration, but allows moisture vapor to vent or breathe out of underlying substrate.
- Dirt Pick-Up Resistance (DPR) technology for longest lasting reflectivity
- Waterproofs as part of a Henry® Maintenance System (HMS)
- Bright white with excellent hiding power
- Reflects >80% of sun's heat and UV rays after 3 years; prolongs roof life
- Lowers roof and interior temperatures; reduces air conditioning costs
- Mildew and stain resistant
- 12 year limited warranty with 1-time application
- Approximately 100 sq. ft. per gallon per coat
In speaking with Ryan, Laura and Alysha from Skoolie Nation they said that during the day of applying the first coat in the sun, the internal temperature dropped 22 degrees after the first coat was applied. The walls of the bus were also insulated at that point so keep that in mind. They applied a total of 4 coats to really ensure that all seams, rivets, etc were completely waterproofed. Here is a couple photos from them applying the roof sealant on the school bus conversion.
The second roof coating that people tend to talk a lot about and recommend is Pro Guard's Liquid Roof RV Coating and Repair. While it's significantly more expensive, it's been tried and tested by RV owners and RV repair shops for years. You have to use a drill and mixer to combine the two components before applying and once you activate the two components it's game on and you better be prepared to apply it. It also can't be used later for another application unless you put it in your freezer. Here's a little info from their website:
Seals and protects your RV from water damage and expensive fuel loss due to drafts. No other product can match the
durability of EPDM Rubber and LIQUID ROOF® is backed by a 5-year warranty. LIQUID ROOF® is available in white.
Each gallon covers approximately 42 square feet.
All these features in a single product
* Chemical resistant * Ease of application * Long-term durability * UV and Ozone resistance *
* Produces a seamless membrane * Excellent flexibility and elongation *
* Outstanding ponding water resistance *
* Temperature resistance from –60°F to 300°F *
TO LEAK PROOF:
FLASHINGS – RIPS – TEARS
CRACKS – DELAMINATED SEAMS
CAN BE USED OVER:
METAL – FABRIC – RUBBER
FIBERGLASS – FOAM – CONCRETE
Regardless of what roof coating you decide to use for your school bus conversion I'd recommend applying it all the way to the rain gutter on the sides of your skoolie as well as the slanted marker light section in the front and back if your bus has that style. Avoid slathering silicone all over if you can. I hit every seam and rivet on my school bus conversion and ended up scraping it all off later as it wasn't good enough.
Overall it'll probably take you 3-7 days to complete depending on drying time, weather and humidity so plan accordingly. Below are the tools and products to consider for the task at hand. If you're anything like me Amazon Prime is a life and time saver!