Guide to California’s Mold Law (SB 655)
If you have ever tried to read the actual text of California Senate Bill 655, you probably ended up with a headache. It is packed with dense legislative jargon about “substandard conditions” and “amendments to the Health and Safety Code.”
But if you are dealing with a mold problem right now, you do not need a law degree—you need clear answers.
Whether you are a tenant worried about your health, a landlord trying to protect your property, or a manager balancing both, this guide breaks down exactly what the law says, who is responsible, and what you need to do next.
The Big Picture: What is SB 655?
Passed to clear up years of legal gray areas, SB 655 officially added visible or demonstrable mold growth to California’s list of conditions that make a building “substandard” (Health and Safety Code Section 17920.3).
Before this law took effect, the state housing code mentioned “dampness,” but it did not explicitly name mold. That made it incredibly difficult for city code enforcement officers to issue citations and even harder for tenants to prove a unit was legally uninhabitable.
Now, significant indoor mold is treated with the same legal seriousness as a major rodent infestation, a lack of heating, or broken plumbing. However, the law comes with explicit boundaries: it requires official verification, proper notice, and clear accountability for both sides.
SB 655 For Tenants – Your Health and Rights
If you spot green, black, or powdery growth on your walls, baseboards, or ceilings, the law is on your side—provided you follow the correct legal steps.
1. Does visible mold automatically mean I can break my lease or sue?
No. You cannot simply stop paying rent or walk away from your lease the moment you see a spot of mold. For SB 655 to protect you in a habitability claim, a local health officer or city code enforcement official must inspect the property and officially determine that the mold is severe enough to endanger your health.
2. How do I legally report mold to my landlord?
Under Civil Code Section 1941.7, a landlord is not legally obligated to fix a mold problem until they actually know it exists. To protect your rights, follow this protocol:
- Put it in writing: Send an email, text, or letter immediately. Avoid relying solely on a phone call.
- Take photos: Document the visible growth clearly, using a coin or phone next to it for scale.
- Keep a paper trail: Note the exact date you discovered it and the date you sent the notice.
3. Can a mold problem be blamed on me?
Yes. The law explicitly excludes mold that is minor and found on surfaces that naturally accumulate moisture—like bathroom tile, shower grout, or window sills. If the mold is a direct result of “poor housekeeping practices”—such as never wiping down the shower, sealing windows shut during hot baths, or blocking air vents—the responsibility falls on you, not the landlord.
SB 655 For Landlords & Managers – Compliance and Liability
For property owners and managers, a mold complaint is a clock that starts ticking. Ignoring it carries steep risks.
1. What are my legal obligations once a tenant reports mold?
Once you receive notice, you have a legal duty to maintain a habitable dwelling. This means you must inspect the issue promptly. If there is an active mold problem caused by a structural failure—like a leaky roof, broken pipe, or failed waterproofing—you are legally required to fix the moisture source and safely remediate the mold.
2. Can I face criminal penalties for ignoring mold?
In extreme cases, yes. Because SB 655 places mold under the State Housing Law, failing to comply with an official code enforcement “notice to repair” is classified as a misdemeanor. Persistent refusal to fix a cited housing violation can result in fines up to $1,000, property condemnation, or even jail time.
3. How do I protect myself from bogus or weaponized mold claims?
SB 655 actually built in strong protections for landlords to stop unscrupulous lawsuits. Under the law:
- No more “hidden mold” surprises: Tenants cannot sue you over hidden air spores or self-declared air tests without giving you notice and an opportunity to inspect visible growth first.
- Right of entry: You have the legal right to enter the dwelling (following standard 24-hour notice laws) to inspect and make necessary repairs. If a tenant blocks your access, they weaken their own legal standing.
Clear Answers to Common Legal Gray Areas In SB 655
1. Does the landlord have to pay for professional air testing?
The law specifically targets “visible or otherwise demonstrable” mold. It does not force a landlord to pay for expensive third-party air sampling or hidden wall cavity testing just because a tenant requests it. However, if code enforcement gets involved or there is a major dispute about whether a stain is actually toxic mold, hiring an independent, certified inspector is the smartest way to protect both parties with hard data.
2. What exactly counts as “demonstrable” mold?
The law defines mold as microscopic organisms or fungi that grow in damp indoor conditions. “Demonstrable” means it can either be seen with the naked eye or verified through physical tools—such as a professional moisture meter reading showing rotting, saturated drywall behind a wall covering. It does not cover normal, everyday bathroom mildew that can be easily sprayed and wiped away with a standard household cleaner.
The Step-by-Step Resolution Workflow
When a mold issue arises, following this precise order ensures compliance with California law and prevents minor issues from spiraling into costly legal battles.
1: Discovery & Photos
Day 1
The resident spots visible indoor mold growth. They immediately photograph the affected areas and note any secondary signs, like water stains or peeling paint.
2: Formal Written Notice
Day 1–2
The tenant sends a written report to the landlord or manager. Legally, the landlord’s clock to respond and repair only begins once this official notice is received.
3: Inspection & Source Fix
Within 1–5 Days
The landlord or a maintenance professional inspects the area. They must locate and repair the underlying moisture source (the leak or structural failure) first, or the mold will simply grow back.
4: Safe Remediation
Within 30 Days Max
The visible mold is safely cleaned or cut out. For areas larger than 10 square feet, a certified mold remediation team should handle containment to prevent spreading toxic spores through the property’s ventilation.
5: Official Sign-Off
Post-Completion
The area is dried completely, repaired, and painted. If a code enforcement officer originally issued a citation, they perform a final walkthrough to clear the property and close the case.
The Golden Rule of Mold: You can clean visible mold all day long, but if you do not stop the water or humidity that caused it, you haven’t solved the problem. True compliance under SB 655 requires fixing the moisture source first.