4.9 
19 *The Angi rating for Mold Testing And Remediation companies in Walnut, CA is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Mold Testing And Remediation needs.
*The HomeAdvisor rating for Mold Testing And Remediation companies in Walnut, CA is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Mold Testing And Remediation needs.
Last update on August 24, 2026
Serving Walnut, CA and surrounding areas
Approved
In business since 2001
Free estimates
Emergency services offered
"Customer service was excellent and service was on time/efficient. Pricing was competitive as well."
+96
Serving Walnut, CA and surrounding areas
Approved
In business since 1995
Free estimates
Emergency services offered
"All work was completed on time with exceptionally high-quality work. All workers were introduced to me, making me comfortable with strangers in my home. All workers wore masks and used all health recommendations. I was brought into every step of the process and the process was explained. The total cost was as estimated. The price was about half of the estimate of other contractors. I was very satisfied. I recommend this 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."
Serving Walnut, CA and surrounding areas
Approved
Super Service Award Winner
In business since 2011
Free estimates
Warranties offered
"Not only did Matt and his crew do an excellent job but they went above and beyond their excellent service."
+6
Serving Walnut, CA and surrounding areas
Approved
In business since 2018
Emergency services offered
Small jobs welcome
"very throughout the house checking for mold and taking all the samples air and space"
+71
Serving Walnut, CA and surrounding areas
Approved
In business since 2019
Free estimates
Emergency services offered
"Very approachable and the work performed was top notch."
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
Serving Walnut, CA and surrounding areas
Approved
Super Service Award Winner
In business since 2021
Emergency services offered
Small jobs welcome
"Excellent verbal and written communication. Timely LAB Report for three AIRBORNE tests for mold. A professional approach in offering additional services to help the customer with mold remediation."
Serving Walnut, CA and surrounding areas
Approved
In business since 2006
Free estimates
Emergency services offered
"Original estimate, management and office staff, arrival and completion time, care of customer's property, clean-up and price were all excellent.
"
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."
+9
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