Mold Complaints: When It’s Not a Leak—It’s a Lifestyle

In Berkeley’s cool, coastal climate, it’s not uncommon for landlords to receive complaints about mold. But not all mold growth stems from leaks or structural issues. In many cases—especially in older buildings without central ventilation—mold can result from everyday living habits.

Why You Still Need to Investigate

Every mold report should be taken seriously. Landlords have a legal obligation to respond to habitability concerns. But before you call in a mold testing company (which the California Department of Public Health does not recommend), it’s worth assessing whether housekeeping and ventilation practices are contributing to the issue.

Common Tenant-Related Causes of Mold

Here are some of the most frequent contributing factors we see:

• Not using fans or opening windows during showers or cooking

• Drying clothes indoors without ventilation

• Furniture pushed directly against exterior walls

• Windows left closed at all times, even in mild weather

• Infrequent cleaning of window tracks, carpets, or bathrooms

What Landlords Can Do

• Include BPOA’s Mold Disclosure as part of your lease package. It outlines both tenant responsibilities and when to report moisture problems.

• Conduct a pre-winter walkthrough to look for condensation issues, blocked vents, or signs of inadequate airflow.

• Offer tenants practical tips (via email or a posted flyer) on how to prevent mold in Berkeley’s mild, damp climate.

A Word on Clean-Up

If mold covers less than 10 square feet, the U.S. EPA advises that no professional remediation is needed. Tenants can safely remove minor mold using white vinegar or detergent (not bleach), as outlined in your disclosure addendum.

When to Take Further Action

Tenants should notify you immediately if they discover any of the following:

• Mold or mildew-like growth that cannot be removed with household cleaner

• Water leaks, standing water, or excessive indoor moisture

• Malfunctioning or inoperable windows, doors, or exhaust fans that prevent proper airflow

• Failure or breakdown of heating, ventilation, air conditioning, or laundry systems