Roof Coating in Los Angeles
& the San Fernando Valley

A roof coating is a thick, liquid-applied membrane rolled or sprayed over an existing low-slope roof. Over a roof that is dry and still adhered, it seals the surface, bridges hairline cracks and turns a dark, sun-baked cap sheet into a bright reflective one. It costs a fraction of a tear-off because nothing comes off the building.

It is only the right call over a sound roof. Before we quote a coating we check the roof for trapped moisture, blisters, open seams and ponding. Wet insulation or a membrane that has let go of the deck means replacement, because a coating would seal the water in. When the roof qualifies, the seams, flashing, drains and scuppers are repaired first, the surface is cleaned, primer goes on where the membrane needs it, and the coating goes on at the thickness the manufacturer requires for its warranty.

Silicone and acrylic are the two common systems. Silicone holds up to standing water and is the usual choice on flat roofs that pond after rain. Acrylic elastomeric suits well-drained low-slope roofs and metal roofs, stays flexible and is easy to recoat later. Both come in white, reflective formulations rated by the Cool Roof Rating Council.

In Valley heat the reflective surface matters as much as the waterproofing. A white coating reflects most of the sunlight a dark roof absorbs, which keeps the membrane and the rooms under it cooler and slows the aging of everything beneath it.

Most of the Valley's coatable roofs are the low-slope sections nobody sees: torch-down over garage conversions and room additions in Van Nuys, Reseda and North Hollywood, built-up and modified-bitumen roofs on mid-century homes in Sherman Oaks and Studio City, and the flat roofs over storefronts, offices and apartment buildings along Ventura Boulevard, Van Nuys Boulevard and Sherman Way.

A coating suits those roofs while they are still sound: a torch-down cap sheet that has lost its granules but not its bond, a TPO membrane that has chalked but not split, a built-up roof with a few blisters but dry insulation. It does not suit a roof that is wet underneath, and no coating fixes a drainage problem; that gets fixed first.

LADBS lists the application of an approved coating to an existing roof as an express-permit item (no plan check). Under the 2025 California Energy Code the cool-roof rules for re-roofing cover replacements, recovering and re-coating: when more than half of a single-family roof is re-coated, a low-slope roof in Climate Zones 4 and 6–15 needs an aged solar reflectance of 0.63 and thermal emittance of 0.75 (or SRI 75), and nonresidential low-slope roofs meet the same numbers when more than 50% of the roof or 2,000 sq ft, whichever is less, is altered.