Do this first
What to do right now
- Stop the active leak first. Coating is not an emergency product: it needs a dry surface and dry weather to cure.
- Get a moisture survey or core cuts before committing. Coating over wet insulation seals the water in and destroys the deck.
- Photograph the whole roof field, not just the leaks, an applicator needs to see the general condition to quote honestly.
- Ask which chemistry is being proposed and why: silicone, acrylic, polyurethane and asphalt-based systems behave very differently.
- Ask specifically whether the system offered is Title 24 compliant and CRRC-rated if the work will be permitted in Rancho Cucamonga.
- Confirm the mil thickness and the number of coats in writing. Coating warranties live or die on applied thickness.
What a coating restoration actually is
A restoration coating is a fluid-applied membrane rolled or sprayed over an existing roof. Seams, penetrations and flashings are reinforced first with fabric embedded in the coating, then the whole field is coated to a specified dry film thickness. Done properly it becomes a monolithic, seamless surface over the old roof, and it avoids a tear-off, a landfill bill and the disruption of exposing the building.
Choosing the chemistry
Silicone handles standing water better than anything else and holds its reflectivity well under UV, which makes it a common choice on Southern California roofs with imperfect drainage. It stays slick when wet and is fussy to recoat later. Acrylic is cheaper, breathes, and works well on a sloped roof in a dry climate like Rancho Cucamonga, but it re-emulsifies in ponded water, so it is the wrong product where puddles sit. Polyurethane is tough and abrasion-resistant, useful where there is foot traffic to a rooftop unit. Asphalt-based emulsions suit older built-up and modified bitumen roofs.
Compatibility with the existing surface is not optional. Acrylic over an oily aged bitumen roof will fail. Silicone over an un-primed TPO will fail. Ask what primer is specified and what the adhesion test showed.
When coating is the wrong answer
A coating is a waterproofing layer, not a structural repair. It will not create slope, it will not dry out saturated insulation, and it will not save a deck that has already gone soft. If a moisture scan shows significant wet insulation, that area has to be cut out and replaced before any coating goes down. An applicator who skips the moisture survey on an old roof is selling you a two-year fix.
Title 24 and cool roofs in California
Most reflective coatings are white and inherently cool-roof products, which lines up well with California's Title 24 energy standards. Where the standards apply, low-slope roofs are typically required to meet minimum aged solar reflectance and thermal emittance values, commonly around 0.63 aged solar reflectance and 0.75 thermal emittance for nonresidential low-slope roofs in the prescriptive path, verified through a CRRC-rated product listing. Requirements vary by climate zone, occupancy and the scope of the work, so confirm what applies to your building with the Rancho Cucamonga building department before the material is ordered, the rated product listing is what an inspector will ask to see.
