MoldHelpUSAWhy mold is common in San Jose
The San Jose station averages about 16 inches of precipitation a year under NOAA's 1991–2020 normals, almost all of it from November through March. With summers this dry, a damp wall in July almost always points to plumbing, an air conditioner, or an irrigation line rather than the weather.
When the creeks rise, though, they rise hard. In February 2017, Coyote Creek overflowed, about 14,000 residents were ordered to evacuate, and the Rock Springs neighborhood was the hardest hit; SPUR later estimated about $73 million in property damage. Homes that took creek water had wet drywall, insulation, and flooring for days.
About 60% of San Jose's homes were built before 1980, according to the Census Bureau, many of them single-story tract homes from the 1950s through the 1970s, on slabs or low raised floors. Original supply lines and drains in those houses are a common source of slow leaks. The EPA's advice to dry wet materials within a day or two is what keeps a leak from becoming a remediation job.
Source: NOAA climate normals
Mold services in San Jose
What mold work costs in Santa Clara County
| Service | Typical range |
|---|---|
| Mold inspection, national range | $300–$1,000 |
| Lab sample, per sample (national) | $50–$350 |
| Typical remediation job (national) | $1,100–$3,400 |
These are national numbers from Angi and HomeGuide; we have not found a San Jose survey we rely on. A slab leak usually adds plumbing work to locate and reroute the line, and creek-flood jobs cost more because contaminated materials are removed. See the remediation cost guide.
California mold licensing: what to check
There is no California mold license, so check the CSLB contractor license for any San Jose job of $1,000 or more or any job that needs a city building permit. If a slab leak caused the mold, ask who will repair the plumbing and whether the reroute needs a permit. Get liability insurance and a written scope listing rooms, materials, and how the result will be checked. See the California page.
Will insurance cover it?
Coyote Creek showed San Jose homeowners the gap between policies: creek water that rose into homes was flood damage, covered only by flood insurance. A sudden pipe or water heater failure is more likely to be covered by a homeowners policy, often up to a mold limit, while a slab leak that ran for months is usually called gradual. Document the water before cleanup and report early. If a claim stalls, the California Department of Insurance takes complaints. See does insurance cover mold.
Areas we connect you in
Willow Glen, Rose Garden, Naglee Park, Japantown, Rock Springs, Berryessa, Evergreen, Almaden Valley, Cambrian Park, Blossom Valley, East San Jose, West San Jose, and surrounding neighborhoods of San Jose.