Mold Inspection & Remediation in California

No state mold license. California does not license or certify mold inspectors, assessors, or remediators. The Toxic Mold Protection Act of 2001 asked the state to study exposure limits, and the Department of Public Health concluded that science-based limits could not be set, so there is still no numeric state limit for mold in a home. Results are judged by comparison, not against a legal threshold.

Contractor license. The Contractors State License Board requires a license for any construction job of $1,000 or more in combined labor and materials, or for any job that needs a building permit. AB 2622 raised the old $500 threshold, effective January 1, 2025. Mold removal often ends with new drywall, flooring, or framing, so check the company with the CSLB license lookup before you sign.

What to ask for. Ask for a certificate of general liability insurance, the crew's training or industry certifications, and a written scope that lists rooms, materials, and how the result will be checked. Many companies follow the ANSI/IICRC S520 standard. California does not stop one company from both testing and remediating; an independent inspection before work and a separate final check give you a second opinion.

Most of California has a Mediterranean climate: dry summers and a short winter rainy season. NOAA's 1991–2020 normals put downtown Los Angeles at about 14 inches of precipitation a year, San Diego at about 10, Sacramento at about 18, and downtown San Francisco at about 23, almost all of it from November through March. When atmospheric rivers arrive, a year's worth of problems can come in a few days, as when downtown Los Angeles logged about 8.5 inches over three days in February 2024.

Because the air is dry much of the year, mold in a California home usually points to a specific water source: a plumbing or slab leak, a roof or window that failed in a storm, an air conditioner drain, or fog and condensation in coastal areas. The EPA recommends drying wet materials within 24 to 48 hours and keeping indoor humidity below 60%.

California homeowners policies usually separate sudden water from gradual damage. A burst pipe, a failed water heater, or a split supply line is the case a homeowners policy is most likely to cover, often with a separate mold limit. A slab leak or a slow drip under a sink that went on for months is commonly treated as gradual or maintenance and excluded, though some policies cover the cost of finding and reaching a sudden leak.

Storm water that rises from outside is flood water and needs a flood policy, which most California homeowners do not carry; rain that comes in through a roof damaged in the same storm is more likely to be a homeowners claim. Photograph damage before cleanup and report it promptly. The California Department of Insurance takes consumer complaints. See does insurance cover mold.

Our phone line is for homeowners. If you rent in California, state law gives you specific protection. Under Health and Safety Code section 17920.3, visible mold growth is a substandard housing condition when a health or code enforcement officer finds it; minor mold on surfaces that get wet in normal use, such as shower tile, is excluded. Landlords must also keep rentals fit to live in under Civil Code section 1941.1, which includes effective waterproofing and weather protection.

Give your landlord written notice of the leak and the mold, keep a copy, and take dated photos. If repairs are not made, contact your city or county code enforcement or environmental health office, which can inspect and cite the condition, or a tenant rights organization. California's tenant remedies, such as repair and deduct, have specific limits, so read the rules before using them. For your belongings, see renters insurance and mold.