In Arizona, the coating on a foam or flat roof does most of the hard work. It blocks the UV rays that break down foam, seals the surface against water and reflects heat away from the house. When it wears thin, the roof underneath starts to fail. Recoating on schedule is one of the most cost-effective things you can do for a flat roof. Call or text (602) 339-9540 for a free assessment.
Is your roof due for a coating?
- The surface looks chalky, faded or patchy
- You can see tan or orange foam showing through
- The coating is cracking, peeling or blistering
- It has been 5 to 10 years since the last coating
- You see more ponding than you used to
- Your upstairs or the rooms under the flat section are getting hotter
Which roofs get coated
- Spray foam (SPF) roofs: a coating is required. Foam cannot survive Arizona sun without it.
- Flat and low-slope roofs with rolled roofing or modified bitumen, when the material is still sound.
- Patio and addition roofs that tie into a tile or shingle main roof.
- Some metal roofs, to stop rust and reflect heat.
Coatings are not used on tile or asphalt shingle roofs. Those need tile repair or shingle repair instead.
How recoating works
- Inspection. The roofer checks for wet or damaged foam, blisters, holes and ponding. Coating over wet foam traps water, so problems are repaired first.
- Cleaning. The surface is cleaned of dust, debris and loose coating. In the desert, dust removal is critical for good adhesion.
- Repairs. Bare foam is scraped and patched, blisters are cut out and filled, holes are sealed, and drains and edges are addressed.
- Primer, if needed, depending on the existing surface and the coating system.
- Coating. One or more coats are applied to the manufacturer's specified thickness, with extra attention at edges, penetrations and seams.
- Final check and photos.
Types of coatings
| Coating | Notes |
|---|---|
| Acrylic elastomeric | Common, affordable, highly reflective; best where water does not pond |
| Silicone | Handles ponding water well and holds up to UV; can be harder to recoat over later |
| Urethane | Tough and impact-resistant; good for roofs with foot traffic |
The roofer will recommend a system based on your roof's slope, drainage, existing coating and budget.
Benefits of a reflective roof coating
- Protects the roof, especially foam, from UV breakdown.
- Seals small cracks and seams against water.
- Reflects sunlight, which can lower roof surface temperatures and reduce heat entering the home.
- Extends roof life and postpones replacement when done on schedule.
When coating is not enough
If foam has absorbed water across large areas, or rolled roofing is cracked and brittle throughout, a coating will not fix it. The roof needs repair or replacement first. The roofer will tell you honestly which situation you are in.
Best time to recoat
Coatings need dry weather and temperatures within the manufacturer's range. In the East Valley, fall and spring are ideal. Recoating before monsoon season, which starts June 15, gives the roof the best protection for the storms.
Frequently asked questions
How long does a roof coating last?
It depends on the coating type, thickness and exposure. Arizona roofing pros commonly recommend recoating foam roofs every 5 to 10 years.
Can you coat over my existing coating?
Usually, after cleaning and repairs, as long as the new coating is compatible with the old one. Some silicone coatings require a specific approach. The roofer will check.
Will a coating stop my roof from leaking?
A coating seals small cracks and protects the surface, but it will not fix wet foam, rotted decking or failed flashing. Those must be repaired first.
Does a white roof coating really keep the house cooler?
Reflective coatings can lower roof surface temperatures significantly, which can reduce heat flowing into the rooms below. Results vary by home, insulation and ventilation.