A roof coating is a liquid applied layer that cures into a seamless membrane over an existing roof. It can extend the life of a roof that is aging but still sound, and a reflective coating can cut heat gain in sunny climates.
The main coating types
| Coating | Strengths | Watch for |
|---|---|---|
| Silicone | Handles ponding water and ultraviolet light well | Hard to recoat with anything but silicone; can collect dirt |
| Acrylic | Reflective, easy to apply, water based | Weaker where water ponds |
| Polyurethane | Tough and impact resistant | Usually needs a top coat for UV protection |
| Elastomeric (general term) | Stretches and recovers with temperature changes | The term covers several chemistries; ask which one |
When a coating makes sense
- The membrane is aged but mostly intact
- The insulation underneath is dry, confirmed by a moisture survey
- The roof deck is sound
- The building owner wants to delay a full replacement
When it does not
- Wet insulation across a large area
- Widespread membrane failure or deck damage
- A roof type or condition the coating manufacturer will not warrant
What a proper coating job includes
Cleaning, repairing seams and flashings, replacing wet areas, priming where needed, and applying the coating at the thickness the manufacturer specifies. Thickness matters, so ask how it will be measured.
Coatings are a common form of roof restoration.
Common questions
Can a coating fix a leaking roof?
A coating is not a patch. Leaks and wet insulation must be repaired first. A coating then adds a new protective surface over a sound roof.
Do white roof coatings save energy?
Reflective coatings can lower roof surface temperature and cooling demand, especially in hot, sunny climates. Savings depend on the building, insulation and climate.