When a flat commercial roof starts leaking, the first quote a building owner often hears is for a full replacement. Sometimes that is the right answer. But when the deck and insulation are still sound, a roof coating can restore the roof you already have, without the tear-off.
Here is why more Michigan building owners are asking about coatings, and how to tell whether your roof is a good fit.
What a roof coating actually is
A roof coating is a fluid-applied layer that goes over your existing roof and cures into a seamless, flexible membrane. Coatings are made from materials like silicone, acrylic and polyurethane. The system we install, GacoRoof from Gaco, is a 100% silicone coating applied over a cleaned and repaired roof, sealing seams, flashings and penetrations in one continuous surface.
It is not paint. A properly specified coating is a roofing system, with its own thickness requirements and its own warranty.
Why owners choose a coating over a replacement
No tear-off. Removing an old roof means dumpsters, noise, exposed decking and a building that is hard to work in. A coating goes over the roof that is already there.
No primer on most roofs. GacoRoof bonds directly to most existing roof surfaces, including built-up, modified bitumen and metal, without a separate primer coat, which keeps the job shorter.
Built for ponding water and snow. Silicone stays flexible and keeps its grip even where water ponds or snow sits for weeks, which is exactly what a Michigan flat roof goes through every winter.
Low odor. Because the coating is low odor, staff, tenants and customers can keep using the building while the crew works overhead.
A 15 or 20 year warranty. Depending on the roof and the coating thickness, a coated roof can carry a 15 or 20 year warranty.
Reflectivity. A white coating reflects sunlight, which can keep the space below cooler in summer.
Is your roof a good candidate?
A coating works best when the roof underneath still has life in it. Your roof may be a good fit if:
- It is flat or low slope
- The membrane or metal is aging but still attached and mostly dry underneath
- Leaks are at seams, flashings or penetrations rather than across the whole deck
- Your building cannot shut down for a full replacement
If water has soaked the insulation across large areas, a coating is not the right fix, and a good contractor will tell you so.
What a coating project looks like
Every project starts with an assessment of the roof. If a coating is the right call, the roof is cleaned, the problem areas are repaired, and the coating is applied across the whole surface to the thickness the warranty requires.
On large roofs the difference is easiest to see. In 2026 we coated a 54,000 square foot roof at Northwood University in Midland with a Gaco silicone system in about two weeks, with no tear-off and the campus running as usual underneath.
Get an honest answer about your roof
Shain Roofing & Sheet Metal Inc. has been roofing commercial buildings across Southeast Michigan for generations, and we travel across the state for larger restoration projects. If your roof is leaking or nearing the end of its life, schedule a free assessment and we will tell you whether a coating, a repair or a replacement makes the most sense. Read more about our commercial roof coatings.
