Water Leak or Flood? When to Test for Mold Afterward
A leaking water heater, a burst pipe, an overflowing tub or a roof leak during the winter rains: water damage is one of the most common causes of mold in Los Angeles homes. Here’s what to do right away, and when to test for mold after water damage.
The 24–48 hour window
According to the EPA, if wet materials are dried within 24–48 hours after a leak or spill, mold usually won’t grow. After that, the risk rises quickly, especially inside walls, under flooring and beneath cabinets where water is hidden and slow to dry.
What to do immediately
Stop the water source and turn off power to wet areas if it’s safe to do so.
Take photos and video for insurance and your records.
Remove standing water and wet items such as rugs, boxes and cushions.
Dry the area with fans and a dehumidifier. Open cabinets and closets.
Call your insurance company and, for major damage, a water damage restoration company.
Signs mold may be growing after a leak
A musty smell that appears or gets stronger days or weeks later
Stains, discoloration or bubbling paint near the leak area
Warped baseboards or flooring
Allergy-type symptoms that improve when you leave home
When to test for mold after water damage
The area wasn’t fully dried within 48 hours, or you’re not sure how long it stayed wet.
The water was hidden, for example a slow leak behind a wall or under a sink that went unnoticed.
You notice a musty smell but don’t see mold.
After repairs or remediation, to confirm the air is back to normal before closing walls or moving back in.
For an insurance claim or a landlord/tenant dispute, when you need lab documentation.
Swab or air test?
If there’s visible growth, a surface swab identifies it. If the concern is hidden growth or overall air quality, an indoor air quality test compared with an outdoor sample shows whether spore levels inside are elevated. Many water-damage visits combine one of each.
Fast, flat-rate testing in Los Angeles
$399 for the first sample, $179 for each additional sample in the same visit. Results are typically ready within 2–5 business days after the samples reach the lab. Call (310) 999-8772 or book online. We serve all of Los Angeles County.