Mold Testing in Los Angeles County
Independent mold swab and indoor air quality testing for homes, apartments, condos, rentals and businesses across Los Angeles County — from the Westside and the Valley to the South Bay, Long Beach and the San Gabriel Valley. Lab-verified results and simple, published pricing.
Los Angeles County mold testing prices
Example: 3 samples in one visit = $757 total. We’ll recommend the fewest samples that answer your question and confirm your exact total before we come out. Read more in our Los Angeles mold testing cost guide.
Why Los Angeles homes get mold
Southern California is dry most of the year, but mold only needs a steady source of moisture. The most common causes we’re asked to check in LA County include:
- Plumbing and slab leaks. Slow leaks under sinks, behind showers, inside walls or under floors can go unnoticed for weeks — especially in older homes and apartment buildings.
- Roof and window leaks after winter storms, when water gets into attics, ceilings and wall cavities.
- Coastal humidity. Homes near the beach — Santa Monica, Venice, Malibu, the South Bay and Long Beach — often see damp marine air and condensation in closets, bathrooms and around windows.
- Apartments and shared walls. A leak in a neighboring unit can spread moisture into yours, which is common in multi-unit buildings across Los Angeles.
- Hillside and older homes. Crawl spaces, basements and houses built into slopes can trap moisture and stay damp.
- HVAC and ventilation issues such as condensation lines, poorly vented bathrooms and closed-up rooms.
What we test
Surface swab testing
Tells you what’s growing on a specific spot — a stain on a ceiling, a dark patch on drywall, a spot under the sink. The lab identifies the mold types present.
Indoor air quality testing
Measures mold spores in the air and compares them with an outdoor sample taken at the same time, to help find hidden mold behind walls, under floors or in the HVAC system. Not sure which you need? See swab vs. air testing.
When Los Angeles County clients call us
- A musty smell with no visible source
- After a leak, flood or water damage (when to test after a leak)
- Before buying or selling a home or condo (testing before you buy)
- Renters and landlords who need independent, documented results (LA tenant guide)
- After mold remediation, to confirm the air is back to normal
We only do testing — we don’t sell mold removal — so there’s no conflict of interest in your results.
Los Angeles County cities and areas we serve
Los Angeles & Westside
- Los Angeles
- West Hollywood
- Beverly Hills
- Hollywood
- Santa Monica
- Culver City
- Venice
- Malibu
- Westwood
- Brentwood
- Silver Lake
- Los Feliz
- Echo Park
- Downtown LA
San Fernando Valley & North County
- Burbank
- Glendale
- Sherman Oaks
- Studio City
- Encino
- Van Nuys
- North Hollywood
- Woodland Hills
- Northridge
- Santa Clarita
South Bay, Long Beach & San Gabriel Valley
- Torrance
- Redondo Beach
- Manhattan Beach
- Hermosa Beach
- Inglewood
- Long Beach
- Pasadena
- Arcadia
- Alhambra
- Whittier
- Downey
- West Covina
Don’t see your city? If it’s in Los Angeles County, we cover it. We also serve all of Orange County.
Los Angeles County mold testing FAQ
How much does mold testing cost in Los Angeles County?
$399 for the first sample and $179 for each additional sample collected during the same visit. Most homes need one to three samples.
Do you serve all of LA County?
Yes. We test homes, apartments, condos and businesses throughout Los Angeles County, including Los Angeles, the Westside, the San Fernando Valley, the South Bay, Long Beach and the San Gabriel Valley.
How long do results take?
Sampling takes about 30–60 minutes on-site. Lab results are typically ready 2–5 business days after the samples reach the lab.
Can a renter order mold testing in Los Angeles?
Yes. Tenants often order independent testing to document a problem for their landlord or property manager. Your report is easy to share.
Do I need testing if I can already see mold?
Not always — the first step is fixing the moisture source. Testing helps when you want to know what type of mold it is, whether it has affected the air, or when you need documentation for a landlord, buyer, seller or insurance claim.
Related: Services & prices · Orange County mold testing · Black mold testing · FAQ