Mold in your apartment: what California law says

This is general information, not legal advice. For your specific situation, talk to a tenant rights organization, a landlord association or an attorney.

Is mold in an apartment the landlord’s responsibility in California?

Often, yes. California Health and Safety Code §17920.3 lists conditions that make a building substandard, and paragraph (13) of subdivision (a) reads: “Visible mold growth, as determined by a health officer or a code enforcement officer, as defined in Section 829.5 of the Penal Code, excluding the presence of mold that is minor and found on surfaces that can accumulate moisture as part of their properly functioning and intended use.”¹ That language was added by SB 655 in 2015.

Civil Code §1941.1 then says a dwelling is untenantable if it is a residential unit described in §17920.3, and it separately requires effective waterproofing of the roof and exterior walls and plumbing maintained in good working order.² Those are the two most common sources of the water that mold needs.

What mold doesn’t count?

Minor mold on surfaces that get wet as part of their normal use. Think of a few spots on shower grout or the caulk around a tub. The statute excludes it, and in practice that’s routine cleaning.¹

The other limit is the tenant’s side of the deal. Civil Code §1941.2 says the landlord’s duty to repair doesn’t arise if the tenant substantially fails certain basic obligations, such as keeping their part of the unit clean and sanitary and using plumbing fixtures properly, and that failure contributes substantially to the problem.⁶ The California Department of Public Health notes that a code enforcement officer may find that dampness or mold resulted from a tenant’s actions, such as not using the bathroom fan during showers.⁴

What should a tenant do first?

Tell the landlord, and do it in writing. Civil Code §1941.7 says the obligation to repair mold under §17920.3 does not arise until the landlord has notice of it.³ A dated email or letter is the simplest proof of notice.

A useful report includes:

• Where the mold is, and roughly how big an area
• When you first noticed it, and any leak or water event before it
• Photos with dates, including any water stains or condensation nearby
• A request for repair and a way to reach you to arrange access

Keep copies of everything you send and receive. If you’re not sure whether what you’re seeing is mold, our free photo review can give you a quick read before you write to the landlord.

Who do you call if the landlord doesn’t respond?

Local code enforcement. CDPH advises renters who don’t get a response in a reasonable time to contact their city or county code enforcement agency and ask for an inspection; if the inspector finds a violation, they can require the owner to correct it.⁴

In the City of Los Angeles, the Los Angeles Housing Department (LAHD) investigates complaints about unsafe living conditions and code violations at multifamily rental properties, and you can file a code complaint online or call 1-866-557-7368.⁵ Outside the city limits, contact your own city’s code enforcement office.

Before you withhold rent, deduct repair costs or move out, get advice from a tenant rights organization or an attorney. Those steps carry legal risk if done wrong.

What should a landlord do when a tenant reports mold?

Respond quickly and find the water. CDPH recommends correcting the source of the water, drying or removing damp materials quickly, and cleaning or removing the mold; it warns that bleaching or painting over mold without fixing the dampness usually lets it grow back.⁴

Civil Code §1941.7 allows a landlord to enter the unit to repair mold, provided they follow the notice rules for entry in Civil Code §1954.³ CDPH’s renter booklet also states that since January 1, 2022, landlords must give that booklet to prospective tenants before signing a lease.⁴

Practically, it helps to know whether you’re dealing with a plumbing leak, a roof problem, condensation or a fan that vents nowhere. Each one has a different fix and a different person who should fix it. Our guide on why LA homes get mold covers the usual sources.

Does anyone need a mold inspection?

Not always. CDPH does not recommend testing to identify types or amounts of mold, such as air spore counts, because those results don’t tell you about health risk.⁴ What matters is where the moisture is coming from and how far the damage goes.

An independent inspection is worth it when the source isn’t obvious, when the two sides disagree about what’s there, or when a landlord wants to confirm a repair worked. Our report records moisture readings, photos and locations in plain language that tenants, owners and managers can all read. We serve tenants and landlords alike, and because we never do remediation, nobody is being sold a cleanup.

A mold inspection is $495 for one unit up to 2,000 sq ft. Multi-unit buildings are quoted through our commercial service, and after a cleanup, post-remediation clearance gives both sides an independent check.