A fluid-applied roof coating system is a liquid membrane sprayed or rolled over an existing commercial flat roof, curing into one continuous waterproof layer with no seams. On a structurally sound roof with dry insulation, it extends roof life 10 to 20 years, typically costs 40-60% less than replacement, and carries up to a 20-year warranty. Flat Roof Waterproofing Solutions installs silicone and acrylic systems across West Michigan from Grand Haven, MI, and select projects across the Midwest.
What a Fluid-Applied System Is
Conventional flat roof membranes are sheet goods. EPDM, TPO, and PVC come in rolls and are seamed on the roof. Modified bitumen and built-up roofing are layered in strips. Every one of those seams, laps, and terminations is a place water can get in, and over the life of the roof most leaks trace back to one of them.
A fluid-applied system takes the opposite approach. After repairs and preparation, a liquid coating is applied across the entire roof surface, including seams, flashings, curbs, and penetrations. It cures into a single monolithic membrane that is bonded to what is underneath it. There is nothing to lap and nothing to seam. The existing roof stays in place as the substrate, so there is no tear-off, no disposal, and no exposure of the building interior during the work.
The Two System Types
Silicone
Silicone is the default recommendation for most West Michigan commercial roofs. It is moisture-cured, stays flexible through freeze-thaw cycles, and tolerates ponding water better than other coating chemistries, which matters on roofs where insulation has settled and drainage is imperfect. It is also highly UV-stable. The trade-off is that silicone is harder to recoat with anything other than silicone, and it picks up dirt more readily than acrylic, which reduces reflectivity over time.
Acrylic
Acrylic coatings are water-based, cost-effective, and highly reflective. They perform well on roofs with positive drainage and moderate weathering. Acrylic does not tolerate standing water as well as silicone, so it is not the right choice for a roof with ponding areas. It is easy to recoat and easy to maintain.
We specify the system after the inspection, based on the existing membrane, the drainage pattern, rooftop traffic, and the warranty term the owner wants. We do not have one answer for every roof.
Which Buildings Are Candidates
A fluid-applied system is only as good as the roof underneath it. Candidates have:
- A structurally sound deck with no rot, corrosion, or deflection
- Insulation that is dry, or wet only in isolated areas that can be cut out and replaced
- An existing membrane that is weathered but intact across most of the field
- Seam and flashing failures that are repairable before coating
A roof with widespread saturated insulation, a compromised deck, or multiple failed roofing layers is a replacement candidate, and a coating applied over those conditions will trap moisture and fail. The inspection exists to sort one from the other before any money is spent.
The Process
1. Inspection first
Every project starts with a roof inspection and a moisture survey. The survey identifies wet insulation that must be removed before coating. The inspection documents seam condition, flashings, drains, penetrations, and ponding areas, and produces a written report with photographs and a scope.
2. Preparation and repair
Wet insulation is cut out and replaced. Failed seams are repaired. Flashings, curbs, and penetrations are reinforced, usually with a fabric-reinforced base coat. The roof is pressure-washed to remove dirt, chalking, and contaminants, and allowed to dry. Adhesion is tested on the actual membrane before full application. On some substrates a primer is required.
3. Application
The coating is applied by spray or roller to the thickness the system and warranty require, measured in wet mils and verified as the work proceeds. Multi-coat systems get the base coat, a cure interval, then the top coat. Application is weather-dependent: surface temperature, humidity, dew point, and the chance of rain inside the cure window all govern the schedule.
4. Cure and documentation
Cure time depends on chemistry and conditions, from hours for some silicones to a day or more for others. Once cured, the roof is inspected for thickness and coverage, and the warranty documentation is issued. The building operates normally throughout; most projects do not require any shutdown.
Cost, Service Life, and Warranty
Restoration with a fluid-applied system typically costs 40-60% less than replacement, because it eliminates tear-off, disposal, and new insulation. It extends roof life 10 to 20 years, depending on the system and thickness applied. Qualifying systems carry up to a 20-year warranty. The written scope states the system, the thickness, the warranty term, and the price for your building.
Request a Roof Assessment
Call (616) 947-7652 or send roof plans, a prior inspection report, or photos to [email protected]. We will review them before scheduling the site visit.