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TRUSTED BY WALNUT, CA HOMEOWNERS

  • Average homeowner rating star icon4.9
    Average homeowner rating
  • Verified reviews icon19
    Verified mold testing and remediation services reviews

Top-Rated Mold testing and remediation specialists in Walnut - Updated Nov 2026

Avatar for Mold Solutionz 24/7
Mold Solutionz 24/7
4.2(
35
)
Mold & Toxic Material TestMold & Toxic Material Test - For Business

Serving Walnut, CA and surrounding areas

Approved

In business since 1995

Free estimates

Emergency services offered

"I appreciated Nick for his obvious knowledge and experience with remediation. He was the only one to really talk through options of the 5 companies that came. Everyone else said "this is what we need to do". His pricing seemed fair as well (ALL the quotes I got were expensive). I think he was the 2nd lowest quote. If it's an emergency, I'd say Nick is a fine choice. If you have time, I recommend getting a quote from 5 different companies (or more). An extra bonus with Nick is he has recommended contractors who can do the repairs or plumbing (if needed). But he does not push you to use them or make it seem like you have to use them. It is important to note that Nick only does the remediation. So if they need to cut into a wall or tear something out, it will be an additional cost to then repair it. But I could not find a company that did both remediation AND repair that I was comfortable with."
demo
pic 2
Response time11 hrs
Response rate89%
Recommended by89%of homeowners
Avatar for 911 Certified Mold Testing LLC
911 Certified Mold Testing LLC
5.0(
8
)
Mold & Toxic Material TestIndoor Air Quality TestingMold & Toxic Material Test - For Business

Serving Walnut, CA and surrounding areas

Approved

In business since 1995

Free estimates

Emergency services offered

"A few months ago I used 911 certified mold testing for my home they were referred to me by my plumber. I had a great experience dealing with this company they were very professional and knowledgeable about mold testing. They were also reasonable in their pricing! I highly recommend using this company for mold testing."
Response time4 hrs
Response rate93%
1 neighbors recently requested a quote
Avatar for Night And Day Restoration LLC
Night And Day Restoration LLC
5.0(
5
)
Mold & Toxic Material TestIndoor Air Quality TestingMold & Toxic Material Test - For Business

Serving Walnut, CA and surrounding areas

Approved

In business since 2023

Free estimates

Emergency services offered

Night & Day Restoration LLC specializes in water damage restoration and professional mold testing. Whether you're dealing with a leak, flooding, moisture concerns, or suspected mold, our team will assess the situation, explain what we find, and recommend the right next step.\nWe provide water extraction, structural drying, moisture detection, HEPA air filtration, mold air and surface testing, odor treatment, and structural cleaning. Our team is IICRC Water Restoration Technician (WRT) certified, and we pride ourselves on fast communication, detailed documentation, honest recommendations, and treating your home like it’s our own.\n

48 neighbors recently requested a quote
Avatar for First Source Restoration, Inc.
First Source Restoration, Inc.
4.0(
41
)
Mold & Toxic Material TestToxicity and Mold - RemovalIndoor Air Quality Testing+2 more

Serving Walnut, CA and surrounding areas

Approved

In business since 2006

Free estimates

Emergency services offered

"First Source did a great job with mold remediation after flood. Edi and his assistant went above and beyond what I was expecting. Price was in line with other bids. I hope I don’t have to but I would hire them again."
Infrared light
got mold?
Equipment
mold removal
Plastic Containment

+9

Response time3 days
72 neighbors recently requested a quote
Recommended by88%of homeowners
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Mold Testing and Remediation FAQs, answered by experts

Several factors contribute to the persistent growth of mold in vents, with excess moisture being the most common culprit. Consistent mold formation in vents indicates an ongoing moisture problem within the HVAC system or its surroundings, likely caused by condensation on cool surfaces in areas with high humidity. Moisture accumulation can also result from leaks in ductwork, inadequate ventilation, or insufficient insulation, creating an environment favorable for mold growth. Regular inspections, addressing potential sources of moisture, maintaining proper ventilation, and routine HVAC maintenance can help prevent the recurrence of mold in vents. If the issue persists, seek professional assistance to identify and rectify the underlying problems.

Mushrooms do not harm your yard. In fact, they can actually help improve your lawn health by decomposing woody organic matter in your soil, and breaking it down into nutrients that feed your grass and plants.

Yes, a one-time water leak can cause mold. Depending on the conditions, mold can begin to grow within 12 to 48 hours. The risk increases with the severity of the leak, high humidity, and when water soaks into absorbent materials like drywall. To prevent mold growth, stop the leak immediately and ensure the area is dried completely; running a blower fan for 24 hours is recommended. If you do notice mold, it's best to call a mold removal specialist to address the situation.

The symptoms of mold exposure for sensitive parties include a skin rash, runny nose, coughing, sore throat, burning eyes, and even more severe allergic reactions. If you notice signs of mold exposure, contact a medical professional right away.

Mold in a basement is harmful as it can trigger allergy symptoms, especially for those with asthma and other breathing conditions. Symptoms of mold exposure include itching, sneezing, running nose, and congestion.

The Walnut, CA homeowners’ guide to mold testing and remediation services

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