Top-rated mold & toxic material testers.

Get matched with top mold & toxic material testers in Redwood City, CA

Enter your zip and get matched with up to 3 pros

Matching on HomeAdvisor

Share some details icon
Share some details about your home project.
Match with local pros icon
Within moments, match with highly-rated local pros.
Compare quotes icon
Compare quotes and choose the best pro for the job.

Find Mold & toxic material testers in Redwood City

Avatar for Bio 911
Bio 911
5.0(
75
)

Serving Redwood City, CA and surrounding areas

Approved

In business since 2005

Free estimates

Emergency services offered

"Bio 911 was fast and efficient. Explained every detail of the procedure. The air tests preformed at the conclusion of the remediation process were well within the zone for occupancy. Job well done by all participants."
Mold under window
mold on concrete foundation
after treatment
after remediation
Hoarding cleanup

+18

Response time5 hrs
Response rate98%
Recommended by96%of homeowners
Avatar for Golden Team Builders
Golden Team Builders
5.0(
6
)

Serving Redwood City, CA and surrounding areas

Approved

In business since 2025

Free estimates

Emergency services offered

"Ariel from Golden Team Builders did a great job on my bathroom remodel. He was professional, punctual, and kept me informed throughout. The result was exactly what I wanted. I’d recommend him!"
Kitchen remodel
Kitchen remodel
Kitchen remodel
Kitchen remodel
Kitchen remodel

+31

4 neighbors recently requested a quote
Avatar for American Air Testing Inc
American Air Testing Inc
4.8(
12
)

Serving Redwood City, CA and surrounding areas

In business since 2001

Free estimates

Warranties offered

Professional testing for mold (CIE, CMRS CMC certified), bacteria (sewage spills), asbestos (CAC certification), lead-based paint (LRCIA certification) and chemical odors. Credentials and insured. Free telephone quote on your specific job. No products or services other than consulting. Additional Address: PO Box 12479 San Francisco, CA 94112.

Recommended by83%of homeowners
Avatar for Environmental Mold Sampling LLC
Environmental Mold Sampling LLC
5.0(
4
)

Serving Redwood City, CA and surrounding areas

In business since 2000

Free estimates

Warranties offered

We are an indoor environmental testing company with 15 years in the industry, we maintain an A+ rating with the better business bureau at all times, We do not perform mold abatement as it is a conflict of interest to perform both. We are ACAC certified, fully insured and we keep up with industry standards. We recommend only qualified licensed remediation companies to perform abatement. We are also Infra red certified level 1 We can infra red scan your entire home for hidden moisture, heat and air conditioning loss through openings and lack of insulation. We can also detect leaking or disconnected HVAC ducting in walls and ceilings.

Recommended by100%of homeowners
...
Showing 1-10 of 200
FAQs for mold & toxic material test projects in Redwood City, CA

Some companies offer a no‑cost phone or video consultation that screens for red flags. If the discussion points to a real issue, the pro will recommend a paid on‑site inspection. The complimentary call clarifies whether you need full testing, but it isn’t a substitute for samples, lab work, or a written report. Always confirm what the free service covers before you schedule.

A standard inspection, which includes basic air and surface samples, takes an average of two hours. If the pro needs to probe hidden spaces, such as wall cavities or ductwork, plan on up to six hours. Extra time allows the inspector to reach tight areas, collect additional samples, and document findings. Lab analysis is a separate process and often adds several business days to the overall timeframe before you receive the full report.

Mold thrives where moisture lingers and air flow is poor. Common hotspots include bathroom walls, kitchen backsplashes, window sills, HVAC vents, fireplaces, crawl spaces, and enclosed attics. Check these areas regularly—especially after leaks or high‑humidity weather—to catch growth early and avoid costly repairs.

Unchecked mold can knock 20% to 37% off a home’s market value because buyers worry about hidden damage and health risks. Even after remediation, visible staining or a history of major moisture issues can still lower offers and prolong the time on the market. Addressing mold quickly protects both your property’s structural integrity and its resale appeal.

The Redwood City, CA homeowners’ guide to mold & toxic material tests

From average costs to expert advice, get all the answers you need to get your job done.