Local guide
Mold in San Francisco, California
San Francisco dampness may involve rain entry, a plumbing defect, or condensation in a cool room. Describe the observed condition before choosing a repair or housing complaint.
Local resource reviewed: 2026-10-10
California legal sources reviewed: 2026-05-04
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Start With Your San Francisco Property
Track window wetting and exterior-wall corners by weather and indoor activity. Distinguish water on the room-side glass from wet trim after rain.
San Francisco Department of Building Inspection
DBI's Housing Inspection Section enforces the San Francisco Housing Code, while its Code Enforcement Section handles code-deficiency cases.
Before you contact them:Describe the water entry, damaged material and unit location. Ask which inspection section should receive the complaint and keep written repair correspondence.
Open the official local resource
Local resource reviewed 2026-10-10. An agency inspection or complaint does not replace the repair request to your landlord.
Choose Your Next Action
Clues to Record
These observations help direct an inspection; they do not identify mold type, hidden extent or a medical cause.
- Visible growth or a musty odor that returns after cleaning or source repair.
- New staining, soft drywall, swollen trim or warped flooring beside a leak path.
- Persistent condensation on windows, pipes or other cold surfaces.
- Damp insulation, standing water or damage visible from safe access to an unfinished area; do not enter hazardous spaces to investigate.
Guidance: EPA cleanup decisions | CDC cleanup precautions
Plan the Work and Compare Bids
Record the affected areas, source repairs, containment, material removal and completion checks before comparing contractors. This planner organizes the scope; it does not predict a local price or replace written bids.
State Laws and Rights
Check California notice requirements and the coverage of your tenancy before using a rent remedy or ending a lease. The local reporting contact above can address only the issues within its stated scope.
California mold law snapshot
California has mold-specific rules in addition to general habitability standards.
California recognizes an implied warranty of habitability in all residential leases, requiring landlords to maintain rental properties in a condition fit for human habitation. Under Civil Code Section 1941.1, landlords must ensure adequate weatherproofing, plumbing, heating, and sanitation. Since January 1, 2016, visible mold growth (except minor mold on surfaces that can accumulate moisture as part of their intended use) is explicitly classified as a substandard condition under Health and Safety Code Section 17920.3, making any dwelling with significant mold a violation of habitability standards.
Use the full California guide for tenant rights, landlord responsibilities, and remedies.
Repair Notices and Rent Decisions
Start with these California rules, then check the local regulations section and your property's coverage. A statutory notice period is not always a deadline for finishing every repair. Keep proof of notice and get local legal advice before changing rent payments or ending a lease.
How long does a San Francisco landlord have to fix mold?
No universal mold-specific repair deadline was confirmed for California in the sources reviewed for this guide. Treat timing as notice-and-condition specific: document the mold and moisture source in writing, use the cited habitability or repair source, and get local code enforcement or legal aid advice before treating any deadline as fixed.
Can San Francisco tenants withhold rent for mold?
Rent withholding is allowed under certain conditions when mold makes a unit uninhabitable. Tenants must document the issue, provide written notice to the landlord, and follow proper legal procedures. Under Civil Code Section 1942.4, if a local agency finds the unit uninhabitable and the landlord fails to make repairs within 35 days, tenants may withhold rent. Rent withholding is risky and should only be done with legal guidance, as improper withholding can lead to eviction proceedings.
Does mold in San Francisco require relocation?
Unclear as a standalone statewide mold relocation benefit in the sources reviewed for this guide. If mold or remediation makes the unit unsafe or unusable, California tenants should look to the cited habitability, essential-services, condemnation, disaster, or lease-termination rules and ask legal aid whether rent abatement, substitute housing, temporary vacancy, or termination applies.
Sources: California Health and Safety Code Section 17920.3 | California Civil Code Section 1942
Does mold have to be disclosed in San Francisco?
California has specific mold disclosure requirements under the Toxic Mold Protection Act. Landlords must provide written disclosure when they know, or have reasonable cause to believe, that mold is present that affects the unit and exceeds permissible exposure limits or poses a health threat. Additionally, as of January 1, 2022, landlords must provide the CDPH mold booklet to all prospective tenants before signing a lease. Landlords are NOT required to conduct air or surface tests to determine mold levels, and disclosure is not required if mold was previously properly remediated before a tenant moved in.
Sources: California Health and Safety Code Section 26147 | California Health and Safety Code Section 17920.3
Local Regulations
If your city has additional property-maintenance or code-enforcement rules, start here before filing complaints or making escalation decisions.
Frequently Asked Questions
These FAQs cover the questions readers usually ask next in San Francisco: what to do first, when to test, and how local mold problems connect back to California law.
Who can help with a housing-condition complaint in San Francisco?
What should I inspect first at my home in San Francisco?
What are the first signs of mold in San Francisco homes?
When should I hire a mold professional in San Francisco?
What should I inspect during wet weather in San Francisco?
Are coastal homes in San Francisco more prone to mold?
Cleanup and testing guidance: EPA cleanup guidance | EPA sampling guidance | CDC cleanup precautions
Reference Data and Limits
Reference Sources for San Francisco
These are selected reference-location outdoor and housing-stock inputs. The station does not necessarily represent every neighborhood or elevation in the city. They are not indoor measurements, a mold-growth forecast, or evidence about a particular building. The humidity-month list is a Mold Compass threshold screen, not a NOAA-defined mold season.
Sources: [NOAA precipitation normal, 1991-2020] | [NOAA reference-station outdoor relative-humidity normal (SAN FRANCISCO INTL AP, CA US); 1991-2020] | [US Census ACS median structure year for San Francisco city, California (place GEOID 0667000; exact-place); 2024 ACS 5-year]
Official Resources
Use these official agencies, program links, and state resources when you need primary sources instead of general advice.
Need Help Paying for Repairs?
Find California repair-assistance contacts, financing programs and legal referrals, with eligibility and service limits.
View California Assistance ProgramsLocal Extension Resources
University extension programs often publish research-based prevention and cleanup guidance.
View California Extension Resources