A roof coating is a fluid-applied membrane rolled or sprayed over an existing roof. Sold well, it is one of the best values in commercial roofing. Sold badly, it is a shiny layer over a wet roof that fails in two winters. The difference is almost entirely in what is under it.
When a coating is worth it
- The insulation under the membrane is mostly dry (a moisture survey confirms it).
- The membrane is weathered but sound: chalky, crazed or shrinking, not falling apart.
- Problems are at details that can be repaired before coating.
- You want more years from the roof without the cost or disruption of a tear-off.
When it isn't
- Wet insulation across large areas of the roof.
- A roof already failing everywhere, with seams open across the field.
- Serious ponding that nobody plans to fix (acrylics especially fail under standing water).
- A roof that needs structural or drainage work that a coating can't provide.
Roof leaking right now?
Wausau Superior Flat Roofing repairs, coats and replaces commercial and flat roofs across Wausau and central Wisconsin, with a written price before any work starts. Request a quote online and we’ll call you back.
Silicone vs. acrylic
Silicone tolerates ponding water and weathers well, which is why it is the usual choice for flat roofs. It is harder to recoat with anything but silicone later. Acrylic costs less and works well on metal roofs and other surfaces that shed water quickly, but it softens and fails under standing water. Both need a clean, dry, properly primed surface.
What a cold climate changes
Coatings cure with time, warmth and dry weather. Acrylics in particular need mild temperatures and several dry hours before rain, dew or frost. In central Wisconsin that makes coating a late-spring to early-fall job, and a roof assessed in October is often repaired now and coated next season. Moisture is also a bigger enemy here: water trapped under a coating freezes and expands every winter, which is why the moisture survey isn't optional.
What a proper coating job includes
- Moisture survey and core cuts
- Wet areas cut out and replaced
- Power washing and cleaning
- Seam, flashing and penetration repairs
- Reinforcing fabric at seams, fasteners and transitions
- Primer where the manufacturer requires it
- Coating applied at the specified thickness, measured and documented
See roof coatings and restoration, or price it in the roof cost calculator.