Roof Coatings Don’t Have To Be Scary

Jonathan Miller
May 20
4 min read

The EPDM on our 2018 43' fifth wheel was starting to get gooey. I understand that I might have been able to get a warranty membrane from the manufacturer, as this roof material was under a "recall." But I also knew that the labor was not included in the recall, and that the process would involve removing all the vents, AC units, skylights, gutters, trim, sealant etc. and would preclude being able to get the new material back up under the nose cone and rear cap. We've never had a leak and I didn't want to go through all that effort and potentially cause a worse problem. So I began looking into roof coating options. After deliberating for months, reading reviews until my eyes crossed, and researching the pros and cons of all types of products out there, I finally landed on a product that worked well. Here’s what happened and what I learned.

Looking on-line, watching videos, and reading reviews on Amazon, Google, and YouTube; left me with as many questions as answers.

Acrylic:

The acrylic coatings were advertised as inexpensive, good for all types of roof material, UV resistant, and provide eco-friendly water cleanup. Unfortunately, they can breakdown in areas of pooling water (as often happens on slides or trim/vent areas or the corners of an RV roof.) Acrylics have a shorter life span in harsh climates where they shed mil thickness and can become brittle over time. Water based products can freeze during the application and curing process so you should only apply in temperatures above 50 degrees Fahrenheit and climbing. My takeaway was that an acrylic, modified acrylic, or hybrid-based coating would potentially leak and require more frequent maintenance which may be undesirable.

Silicone:

Silicone Roof coatings are advertised as chemical resistant, durable, with stable UV resistance, and they don't degrade with pooling water. Thick self-leveling coating provides maximum waterproofing and good elasticity. Silicone can be more expensive, dust tends to cling to them, they aren't as impact resistant, and they can be slippery when wet. However, because "nothing sticks to silicone," it's easy to clean the cured roof.

Urethane

Urethane coatings were advertised to have superior adhesion and expansion properties, impact resistance, and are not as slippery when wet. Taken together this combination may be better for areas of high foot traffic (if you walk the roof regularly), or should your RV need any rooftop equipment replaced or serviced. With a small amount of prep, urethane can be recoated at end of life in 10+ years to further extend the life of the roof. These coatings might be the most expensive because of their higher solids content - thicker layers means more material is required. Application is also more involved due to noxious fumes, and the need for multiple coats. Aromatic urethane is applied as a base coat followed by the aliphatic urethane required to add the expansion, UV, and moisture resistance.

Primers:

EPDM and TPO roofs which are two of the most common RV roof materials can benefit from the application of a primer prior to coating. Many manufacturers recommend primer or require it for their warranty to be valid. While others say no primer is needed. All manufacturers recommend thorough cleaning of the existing roof material prior to coating.

Weighing the Costs:

I had already priced many "do it yourself" options that were available online and found the materials to range $300 to $1500 depending on brand and type of coating. Thus, the conundrum. Which product to use? Do-it-Yourself; or hire a professional?

I spoke with several roof coating companies at the Tampa RV Trade Show and found that their pricing was anywhere from $4000.00 to $7000.00. They used various products from hybrid acrylic based products, to silicone, and urethane coatings; each touting their own unique benefits and guarantees. It takes time to do it right, so I know from my own experience that the professionals earn every dollar. They should also have the appropriate insurance in place to protect you and fix a mistake should something go wrong. If you feel this option is best for you, check the reviews and hire a professional.

As I made my way around the booths, I came across the Tremco booth and they walked me through the various products they had on display. I explained to the sales rep that I was a registered RV tech and solar specialist, but I'd never done a roof coating and was nervous to attempt the job on my own. To my surprise the sales rep offered to deliver the product and do an onsite demo for me on my rig. I was expecting them to do a quick bit of instruction and then wish me luck, but Tremco went above and beyond. To my surprise the rep stayed to help with the cutting in and coating on the main body of the rig which was about 4 hours’ worth of work. Tremco can refer you to professional installers that can do the coating for you, and I think it would be well worth it to have experienced professionals do this work to ensure you don't end up with unsightly runs, drips, or issues from inadequate cleaning or prep work. You want this to be an investment that lasts, not have to get up there and figure out what to do about a mistake you made from inexperience.

If you're reasonably handy, you've painted before, and you're comfortable working on ladders, you might decide to go it on your own and save money on the labor. It's a straightforward process, but it is time consuming. As RV roof coating tips go, I can't stress enough the importance of the cleaning and preparation process. Overall I am very pleased with the Tremco product and how it turned out.