The Ultimate Guide to Gaco Silicone Roof Coatings in Metro Detroit

Welcome back, everybody! Bill Jr. here with Four Seasons Kanga Roof. Whether you are managing a massive commercial facility or living in one of the beautiful older homes in Birmingham, East English Village, or Boston Edison, taking care of your flat roof is an absolute must.

Today, we are diving deep into the proper installation of a silicone coating system for flat roofs right here in Metro Detroit. To help me explain the magic behind these fluid-applied systems, I brought in the heavy hitters: Doug, our technical expert from Gaco, and Mr. Mike Giacalone, our Commercial Service Superintendent.

When done right, a silicone coating can save you the massive upfront investment of a total roof replacement while granting you 10, 15, or even 20 years of life. Let’s hop right into the step-by-step process we use to deliver a monolithic, leak-free finish!

Step 1: The “White Glove” Prep Test

With any coating system, preparation is everything. If people shortcut the system and don’t prep properly, the silicone coating can break down.

Before we apply a single drop of coating, we test the cleaned membrane using a simple “white glove” cleaning test. We wipe the white surface with a rag, and if we see any black residue, we reclean that section. We only move forward when the rag comes up completely clean.

Step 2: Detailing and Patching

Once the roof is pristine, Mike tackles the most critical areas: the flashing, seams, curbs, and pipes.

• The Product: We use GacoPatch, a 100% silicone product that has fibers ground up in it, making it much thicker.
• The Application: We apply the patch up to an eighth-inch thick over all rubber-to-rubber seams. Because GacoPatch already has reinforcement built right in, it often eliminates the need for three-coursing (using Gaco 4200 and polyester mesh) where the membrane meets the metal, though three-coursing is always an option if needed.
• The Cure Time: Since this is a moisture-cure product, we let the patch set up and cure for about four hours, depending on the day’s humidity. This ensures we don’t pull up the patch when we roll the top coat over it.

Step 3: Mixing the Coating

Next, we prepare the star of the show: the Gaco S4200 top coat. Even though this top-tier product is 95% solid—meaning there isn’t a ton of separation in the bucket—you will still see a clear film on top that needs to be integrated.

We always use a heavy-duty corded drill with a mixing paddle to blend the coating thoroughly. This guarantees uniform consistency throughout the product before it hits your roof.

Step 4: The Top Coat Application

For large, wide-open 500-square commercial buildings, spray pumps are often used for peak efficiency. However, in residential areas, we strictly use rollers to eliminate the risk of overspray hitting cars or neighboring houses.

To ensure our customers get exactly the coverage they paid for, we use two foolproof measurement techniques during application:

• The Wet Mil Gauge: We dip a specialized gauge into the wet coating. If we are aiming for a 20-year warranty specification, we look for 36 wet mils, which will eventually dry to 34 mils.
• The Bucket Grid: We grid out a two-square area on the roof, dump a bucket out in that specific section, and spread it evenly.

If an area is rolled too thin, you might see “ghosting” where the dark membrane shows through. Because silicone sticks beautifully to silicone, our team (or a Gaco inspector) can easily spot these light areas and simply roll a little extra coating right over the top until it achieves a perfect, uniform thickness.

Protecting Your Investment

We require our Kanga Care Club maintenance program on every silicone coating system we install. Just like your car needs oil changes, your liquid-installed roof needs ongoing care. Even the best silicone coating can be damaged by careless HVAC contractors dropping tools, severe winds, or falling tree branches.

If damage does occur, the repair is incredibly simple. For a small puncture, we use GacoPatch; for broader scrapes, we clean the area and apply a fresh coat of Gaco S4200.

Next Steps

If you are interested in learning more about silicone coatings to protect your flat roof. Our team would love to help. You can get a free online estimate for a coating by using our free A.I. online estimator here. You can also book your appointment online through our website, or give our amazing customer service team a call at 586-566-0308. They would love to schedule one of our roofing specialists to come out, inspect the roof, and determine if a coating is the right solution for you! 

Sincerely, 

Bill Burkhardt, Jr. 

VP and Owner

Sources & Citations:

• National Roofing Contractors Association (NRCA) – Guidelines on membrane prep and commercial roofing standards.
• Roofing Contractor Magazine – Industry insights on the rise of high-solids silicone roof coatings.
• GAF, CertainTeed, Elevate, Carlisle SynTec – Leading manufacturers of the underlying commercial flat roof membranes (Modified Bitumen, TPO, EPDM) that successfully accept silicone restoration.
• Four Seasons Kanga Roof – Learn more about our flat roof repair and Kanga Care Club maintenance plans.