A metal roof coating isn’t paint. It’s a liquid-applied roofing system that goes right over your existing commercial roof, with no tear-off. On a 68,000-square-foot metal-roofed factory in Monett, Missouri, Shane Waters, who runs the commercial division at Midwest Roofing, answered the questions building owners and property managers ask us most.
Weighing a coating for your building? Get a free commercial roof assessment or call (417) 744-5670.
Metal Roof Coating at a Glance
| Question | Short answer |
|---|---|
| What is it? | A liquid-applied roofing system over your existing roof, with no tear-off |
| Which roofs can be coated? | Most commercial roofs: EPDM, TPO, mod-bit, and metal |
| How thick is it? | About 20 to 40 mil once dry, base and top coats together |
| How fast does it cure? | About 8 hours of dry weather after each coat |
| Does my business have to close? | Usually not. The roof is never opened up, so you can stay open |
| How long does it last? | Shane expects 10 to 15 years on this job, with a manufacturer warranty up to 10 years |
| What does it cost? | On this Monett factory: under $600,000 to coat vs. an estimated $6 to $7 million to replace (heavy rooftop piping) |
What Is a Commercial Roof Coating?
A commercial roof coating is a liquid-applied roofing system that goes straight onto your existing roof. “It’s applied straight to the existing roof itself without tearing off the existing roof,” Shane says. Because nothing is torn off, your building isn’t opened up to the weather while the work happens, and the coating becomes one seamless water barrier over your roof.
Is a Roof Coating Just Paint?
No, and it’s one of the biggest misconceptions we hear. “Generally, when people are thinking about coatings, they’re thinking about painting on the roof,” Shane says. “Coatings are an actual liquid-applied roofing system, creating one seamless water barrier over your entire roof.” On a commercial roof, the base and top coats together dry to about 20 to 40 mil, depending on the warranty. That is a roofing layer, not a coat of paint.
How Thick Is a Commercial Roof Coating?
Much thicker than paint. Most single-ply membranes, like TPO and EPDM, are installed at 45 or 60 mil. A coating goes on in two or three coats, and the base and top coats together dry to about 20 to 40 mil, depending on the warranty. A mil is one-thousandth of an inch. A coating is thinner than a new membrane, but it bonds to your existing roof as one continuous layer, with no seams between sheets.
Which Commercial Roofs Can Be Coated?
Most of them. “EPDM, TPO, mod-bit, and metal are all systems that we can apply coating to,” Shane says. There’s an acrylic or silicone coating engineered for each type of roof. The bigger question is your roof’s condition: the surface has to be sound enough, and clean enough after washing, for the coating to bond to it.
Roof Coating vs. Replacement: When Should You Coat?
Coat while your roof is still in good enough shape for a coating to stick. “You coat when the existing roofing system is still within an adhesionable state and not deteriorated,” Shane says. “Replacement comes after that.” If you’re on the fence, it’s better to look at a coating sooner than later, while it’s still an option for your building.
Can You Coat a Rusty Metal Roof?
It depends on how far the rust has gone. Rust can really affect how well a metal roof coating bonds, so the sooner you look, the better. Left too long, Shane says, a metal roof “will become rusted and lose all of its structural ability,” and at that point replacement is the better call.
Silicone vs. Acrylic Roof Coating: Which Is Right?
It depends on your roof’s slope and how much water sits on it. Here in Monett, we used an elastomeric roof coating. “It has enough slope that it’s shedding water, but it needs to have the elasticity to move with the building,” Shane says. “Silicone does great on lower sloped roofs with lots of ponding water.”
You’ll hear “acrylic” and “elastomeric” used almost interchangeably. As Shane puts it, “elastomeric and acrylic is pretty much the same.” For more, see silicone vs. acrylic vs. elastomeric roof coating.
What Does Prep Work Look Like Before a Roof Coating?
Prep is one of the most important parts of a coating job. Shane breaks it into three phases: clean and wash, repair and prep, then install the coating itself. “Normally, it all falls down to the power washing portion of the roof,” he says. “If the roof is washed good, we can adhere a coating to it.”
- Clean and wash. The whole roof gets pressure washed so the coating can bond to it.
- Repair and prep. Problem spots get repaired before any coating goes down. On this roof, the crew re-drove loose fasteners, primed rusted seams, and used an acrylic roof mastic on seams and details.
- Apply the coating. The coating goes on at the thickness the manufacturer specifies for that roof.
Will a Roof Coating Stop Leaks and Ponding Water?
In most cases, yes, as long as the repairs are done first. “Making the necessary repairs before the coating gets applied will give you a long-lasting, leak-free system in the end,” Shane says. The coating then goes over the whole roof as one seamless water barrier. Your written warranty spells out exactly what’s covered.
Can My Business Stay Open During a Roof Coating?
Usually, yes. Because we don’t open up the roof, your building isn’t exposed to weather while we work, and in most cases you won’t have to shut down operations. Each coat needs about 8 hours with no rain, dew or freezing temperatures in the forecast, so we schedule the work around the weather. “You’ll be able to keep your business open the whole time,” Shane says.
How Long Does a Commercial Roof Coating Last?
On this building, Shane expects the coating system to last 10 to 15 years, backed by a manufacturer warranty of up to 10 years. Terms vary by product and roof, and how long a coating lasts depends on the product, the thickness, and the prep, so get the expected life and the warranty in writing before you sign.
How Much Does a Commercial Roof Coating Cost?
On this job, it came down to the piping. This roof has “so many penetrations of piping on it that would all have to be removed” to replace it, Shane says, putting replacement at $6 to $7 million. “We were able to offer them a warrantable coating system for under $600,000.” Your price depends on your roof, so we give written pricing.
| Option | Cost |
|---|---|
| Full roof replacement | $6 to $7 million |
| Warrantable roof coating system | Under $600,000 |
These were estimates for one building with heavy rooftop piping. They aren’t a quote, and your roof’s price will differ. See typical commercial ranges on our commercial roofing page.
How Do You Choose a Roof Coating Contractor?
Look for a contractor who tests your roof before recommending a coating. “One of the things you want to look for is somebody who’s doing the proper test work before the coating to make sure you’re using the proper coating system,” Shane says. Then make sure they’re local, so they can service the warranty when you need it.
A few questions to ask any coating contractor:
- What testing will you do on my roof before you recommend a coating?
- Which manufacturer’s product will you use, and will you follow their specs?
- What warranty comes with it, and who services it?
- Where’s your nearest office if I need you to come back?
Coat or Replace? Get a Straight Answer.
If you’re weighing a roof coating against a replacement for your commercial building, we’ll tell you which one makes sense. Shane’s team serves commercial properties across central and southwest Missouri, from Monett to Columbia, including commercial roofing in Springfield.
Free roof inspection
Get your free roof inspection
A local pro will look over your roof, take photos of anything we find, and help with your insurance claim if there’s storm damage. No cost, no pressure.
Prefer to talk? Call 573-619-5641
- Free, no-pressure inspection
- Photos and video of what we find
- Help with your insurance claim
- Locally owned and operated since 2008
Request your free inspection
Takes about 30 seconds. We’ll call you to schedule.
Related Reading
- Commercial roof coatings and restoration in Missouri
- Commercial roofing services from Midwest Roofing
- Commercial roofing in Springfield, MO
- Roof repair from Midwest Roofing
- Can you coat a metal, TPO, EPDM, or mod-bit roof?
- Silicone vs. acrylic vs. elastomeric roof coating
Sources
- On-camera interview with Shane Waters, Commercial Roofing Division, Midwest Roofing, recorded on the Monett, Missouri job in November 2026.
- Acrylic Brush-Grade 220 Product Data Sheet — American WeatherStar. The acrylic sealant our crew used on seams, fasteners and penetrations on the Monett job.
- About Roof Coatings — Roof Coatings Manufacturers Association. What roof coatings are, common types and the roofs they go over.
- Roof Coatings FAQs — Roof Coatings Manufacturers Association. Which roofs can be coated, rust treatment, ponding water and how long coatings extend roof life.
- Acrylic Quick Spec: Metal — GAF. Metal roof prep, coating rates and dry thickness by warranty length, and the 8-hour dry-weather window.
- ASTM D6083/D6083M-24, Liquid-Applied Acrylic Coating Used in Roofing — ASTM International. The standard for acrylic elastomeric roof coatings.
- High Solids Silicone Roof Coating — GAF. Silicone coating built to resist ponding water.
- EverGuard TPO Data Sheet — GAF. TPO membrane thicknesses of 45, 60 and 80 mil.
More free guides: roof warning signs with photos, a seasonal roof calendar and ladder safety. See them all in our Homeowner Resource Center.
Free roof inspection
Get your free roof inspection
A local pro will look over your roof, take photos of anything we find, and help with your insurance claim if there’s storm damage. No cost, no pressure.
Prefer to talk? Call 573-619-5641
- Free, no-pressure inspection
- Photos and video of what we find
- Help with your insurance claim
- Locally owned and operated since 2008
Request your free inspection
Takes about 30 seconds. We’ll call you to schedule.
