How to Choose a Roofing Contractor in California (2026)

The CSLB defines a C‑39 roofer as a contractor who “installs products and repairs surfaces that seal, waterproof and weatherproof structures” — using felt, membrane, shakes, shingles, roof tile, slate, metal roofing systems and similar materials. That classification exists because a roof is the one system on your home whose only job is keeping water out. A mistake shows up as a leak, rot, or mold months later. Verifying the license is the cheapest insurance you’ll ever buy: look the company up at cslb.ca.gov and check that the C‑39 is active and the bond and workers’ comp are current.

The C‑39 Roofing classification is governed by the California Code of Regulations, Title 16, and it is specifically about the systems that keep water out of your home. One detail sets roofers apart from most other trades: under Business & Professions Code section 7125, C‑39 contractors are required to carry workers’ compensation insurance whether or not they have employees — the state treats roofing as high-risk enough that there’s no exemption. If a roofer tells you they don’t need workers’ comp because they “work alone,” that’s a reason to check the CSLB record yourself.

A good roof comes with two separate promises. The manufacturer’s material warranty covers defects in the shingles or tile. The contractor’s workmanship warranty covers the installation — and that’s the one that matters most, because the majority of roof leaks trace back to how the roof was installed (flashing, penetrations, fastening), not to a defective product. Ask how long the workmanship warranty runs, what it covers, and whether it survives if the company changes hands. A verbal “we stand behind our work” is not a warranty.

Reroof permit and energy-code triggers vary by jurisdiction, adopted code, roof type, building type, and climate zone. Some jurisdictions use a percentage-of-roof or square-foot threshold (often around 50% or 1,000 square feet) that requires a permit and can trigger a Title 24 energy-code review — but the exact thresholds and cool-roof rules depend on your local jurisdiction, adopted code, climate zone and roof type, set by your local building department. In many Southern California climate zones that also means cool-roof requirements — the roofing product must be tested and certified by the Cool Roof Rating Council, with compliance forms (CF1R/CF2R) submitted at inspection. A licensed contractor pulls the permit, handles those forms, and schedules the city inspection. A contractor who offers to skip the permit “to save you money” is skipping the independent check that the roof was done to code — and leaving you holding the problem at resale.

This is also why the sequencing question matters. If your roof is near the end of its life, replacing it before the panels go on avoids paying twice to remove and reinstall a solar array a few years later — we walk through that decision in should you replace your roof before solar? Tile roofs add their own considerations: clay and concrete tile need experienced handling so panels can be mounted without cracking tiles or creating leak paths, covered in solar on a clay-tile roof. And once you’re choosing the solar side of the project, the same vetting discipline applies — see how to choose a solar installer in California.

None of these automatically means a contractor is bad — a higher price can be justified by a bigger tear‑off, better underlayment, or complex flashing. But each is worth an itemized explanation before you sign: a bid far below every other bid; pressure to decide today; a large deposit up front (California caps home-improvement down payments at the lesser of 10% or $1,000); no written scope; reluctance to pull a permit; a license number that doesn’t match the company name on the CSLB record; or a refusal to provide a workers’-comp certificate. A transparent contractor will happily walk you through any of these.