Top Mold Testing Companies in Houston: Complete Guide

Top Mold Testing Companies in Houston: Complete Guide

Key Highlights

• Hurricane Harvey's flooding in 2017 hit over 150,000 homes in Houston; 76% showed visible mold within weeks, according to a CDC study.

• Houston's average level of moisture is 75% for the whole year. That is higher than most big cities in the U.S.

• When Addicks and Barker let out extra water, homes that were dry during the hurricane still got flooded. This water came days after the rain had stopped.

• A CDC study followed people with weak immune systems living in homes after Harvey. It found that almost 3 out of 4 homes had mold.

Houston's water problem is not just caused by rain. The trouble is also where the water flows when it rains. It stays in some places when bayous fill up. It also causes problems when water needs to be let out to help downtown. Brays Bayou, Buffalo Bayou, and White Oak are not places people come to see. These are the paths that water takes right into people’s homes.

The real risk comes a few weeks after you clean. A house may feel dry on top. You put drywall back up. But in 2018 and 2019, people who check homes found mold growing behind new drywall. The floors stayed wet and never dried. That wetness sat there out of sight for months. When the air is always at 75% humidity, mold does not need much to grow. It just has to be wet enough and warm long enough.

Picking the right person for the job means getting someone who knows these risks. This guide talks about five firms with a TDLR license that work in Houston now.

How Houston Mold Testing Actually Works

An inspection starts with a moisture meter. A person walks around the house. They look for any wet spots in places like crawl space rim joists, attic decking, HVAC pans, and inside walls. The meters show the numbers. If the reading is over 20%, there is a problem that is happening now.

That's the first step. The next step uses samples. The air from your home gets sent to a lab. There, it is compared with air samples taken from outside. If the spore count inside your home is higher than outside, it means there is growth. People also use surface swabs and tape lifts to find out what types are active.

The report you get back should show moisture levels marked on your floor plan. It should also have photos of every area that was checked. You will see lab results that say the exact type of mold they found. A cleanup plan has to be signed by a licensed MAC (Mold Assessor and Consultant). If you do not have this plan, the cleanup team can not do any work because they do not have the legal right to touch anything.

In Houston, a good home checkup begins with the crawlspaces. Homes close to Brays Bayou get looked at for wet spots. Homes built again after Harvey get the walls looked at, because that's the place where water stuck inside causes most trouble. If they just follow a set list in Houston, you don’t get what's worth your money.

Top Rated Mold Testing Companies in Houston

1. FastMoldTesting.com

Website: fastmoldtesting.com/houston

Turnaround Time: ✅ You will get results in 1 or 2 business days.

Value for Money: 5/5 ⭐⭐⭐⭐⭐ (Really good for what you pay.)

Testing only. No cleanup is provided. This is the way they run all of their business. So, the report they give is not shaped by cleanup services that they could sell you later. You get moisture mapping that comes with photos, air samples sent to the lab, and a MAC-signed cleanup plan. You can book for the same day or next day in Houston.

Inspectors in this place know what stuck moisture looks like in new homes. They see what areas are still at risk because water got out and not just because of storms. That kind of local know-how is important.

✅ Benefits:

• Lab results and reports in 1 to 2 business days, this is one of the fastest times in Texas.

• Testing only, no cleanup services offered, so there is no conflict of interest.

• You can book for same-day or next-day testing in Houston.

• A full moisture map with photos and a cleanup plan signed by MAC is included.

• We know a lot about Houston’s bayou flooding and how reservoir water is released.

❌ Disadvantages:

• Does not do mold cleanup. This is an intentional policy to keep reports fair.

🟢 Best for: People who own a home after a water problem, buyers looking at a house during inspection, people renting who need to show the state of the place, and sellers who want to share information about their home.

2. Turnstone EH&S Inc.

https://www.turnstoneehs.net/turnstoneehs.net

Turnaround Time: Call for estimate 

Overall Rating: ⭐⭐⭐⭐⭐

Turnstone is known for its strong background in industrial health and safety. The team often works on air quality in big buildings, buildings with many units, and places where HVAC cross-contamination is a big issue. Their staff has AIHA-approved licenses for asbestos lab work. They focus on testing only. Turnstone serves Houston and Southeast Texas with several offices. One of their offices is in Corpus Christi.

Mold in a building with 40 apartments is not the same as mold in one house. HVAC systems can spread things all over the place. When the air handler is dirty, the whole building will feel it. Turnstone is the company people call for these jobs.

✅ Benefits:

• The staff has over 80 years of work in looking after the environment and looking at health risks on jobs.

• The team holds AIHA-accredited credentials for advanced lab tests.

• They only do testing. They do not clean up, so there is no conflict.

• They cover the Houston and Southeast Texas area. They also have several offices, like in Corpus Christi.

❌ Disadvantages:

• The turnaround time is not shared openly. You have to call them to get an estimate.

• They focus on commercial work, so it might not feel as right for single-family home jobs.

🟢 Best for: Property managers who look after several units, owners of business spaces, and building checks where the one to do air quality tests should have the right skills.

3. Mold Testing Houston

Website: moldtesting-houston.com
Turnaround Time: Standard time is 48 hours, and you can get a 24-hour rush if needed
Overall Rating:5/5 ⭐⭐⭐⭐⭐

Flat rate: up to 2,500 square feet for $550. You get two samples, moisture mapping, and a full report. If you need extra samples, it's $85 each. There is no mystery in the price. There is no need to call for a quote. You will know what you pay up front.

1,091 five-star Google reviews. That's more than any other mold testing group in Houston. This is not because they are perfect, but because people know what they will get and they always give it. Lab work goes to an AIHA-accredited lab. Only testing is offered, with no cleanup jobs and no problems with honesty.

✅ Benefits:

• Flat-rate pricing is $550 for homes up to 2,500 sq ft. There are no hidden fees.

• 1,091 people have left five-star Google reviews. This is more than any other Houston mold testing firm.

• AIHA-accredited lab checks all samples. This makes sure you get trusted results.

• A 24-hour rush is there if you need things done fast.

• We do only testing. There is no conflict with cleanup jobs.

❌ Disadvantages:

• Standard turnaround is 48 hours. Rush service will cost more.

• You can get more samples at $85 each, which can make the total price go up for bigger or harder-to-check homes.

🟢 Best for: Homeowners who want to see the total price right at the start, people who buy homes in Houston, and anyone who is tired of not knowing the real cost in money talks.

4. HoustonMoldFix

Website: houstonmoldfix.com

Turnaround Time: 3 to 5 business days 

Overall Rating: 4/5 ⭐⭐⭐⭐

Pricing is between $300 and $600. It depends on how big the job is. The range is good if you want to check one room you think is bad and not the whole house. They have over 500 five-star reviews. They do testing only. They will give you the name of another cleanup company, and there is no issue between them.

Lab results come in 3 to 5 days. This is not as fast as some other companies. But if you do not need it right away, the low cost is good for a check that you want.

✅ Benefits:

• Entry prices are lower. They start from $300 and go up to $600 for the single or focused room checks.

• There are more than 500 top reviews from real people.

• The checks are for testing only. There is no overlap with clean-up work.

• They point you to other clean-up companies to stay fully independent.

❌ Disadvantages:

• 3 to 5 day turnaround, which is slower than most other companies.

• Price range is less clear than flat-rate firms.

🟢 Best for: People who want to save money, want to check just one room, or have small homes where doing a full check of the home would be too much.

5. Certified Mold Testing and Consulting

Website: certifiedmoldtest.com 

Turnaround Time: Call for estimate

Overall Rating: 4/5 ⭐⭐⭐⭐

This team works in the neighborhoods that are hit the hardest. These areas are Addicks, Barker flood zone, Energy Corridor, Meyerland, Bear Creek, and Katy. If you live in one of these places, the inspectors here will know your water issues much better than someone who works in lots of areas. They focus on testing only. When cleanup is finished, they give you a Texas Certificate of Mold Damage Remediation. You will need this paper for real estate closings or for insurance claims.

The testing-only model makes sure there is no trouble with cleanup. A focus on geography lets them spot issues you might miss.

✅ Benefits:

• The team knows a lot about the flood areas in Addicks, Barker, Meyerland, and the Energy Corridor.

• They do testing only. There is no problem with cleanup.

• They give the Texas Certificate of Mold Damage Remediation, which you need for closings and making insurance claims.

• The team knows when water is released and sees the patterns about bayou floods in the area.

❌ Disadvantages:

• Turnaround time is not shown. You need to call to get a guess.

• They focus on certain areas. It may not help that much if you do not live in their main flood-zone neighborhoods.

🟢 Best for: People living in the Addicks or Barker flood zones, anyone in Energy Corridor or Meyerland, sellers who need papers to close a real estate deal.

What Matters When You're Hiring

Check the license.

 tdlr.texas.gov/mld shows the TDLR licenses that are active, their end dates, and what is happening with them now. If there is no active TDLR license, they can't charge you the right way.

Testing only. If they also do cleanup work, they have a reason to find mold to make more money. Texas law does not let the same firm check for mold and clean it up on the same job. Do not hire a firm that does not follow this rule.

They need to know how water moves in Houston. Bayou flows are all about that part of town. When water is released from the big tanks, it’s also about that area. Putting new drywall over floors that are still wet is a problem we see here after Harvey, not everywhere. Someone checking homes who is new to Houston will not know where to check.

There has to be a written cleanup plan before anyone starts work. A licensed MAC needs to sign this plan before the crew begins fixing things. If the company cannot promise they will give you this paper, it is a warning sign.

Ask the price ahead of time. There should be no "starting at" talk. You need to know if it is $300 or $600 before they come.

The Dual-License Trap

Texas law stops this. The same firm can not check mold and fix it in the same job. If they say there is a big mold problem, they get paid. If they say there is not a problem, they do not get paid. The system is wrong by how it works.

Some firms try to get around it by using two different licenses. But if it is the same company, same phone number, and same address, that is not a real split. It just looks like they are doing things right, but they are not. They will still tell you to use their own cleanup group.

If a company says it has two licenses, ask for both license numbers. You should also ask for proof that they are two different companies. Most of the time, they cannot give this proof.

What an Inspection Costs and How Long It Takes

On-site work takes about 60 to 90 minutes. Lab results are usually ready in 1 to 5 days. How long you wait can depend on the lab and if you pay more for faster work. Some places give results in just 24 hours. Most take about 2 to 3 days.

Your report needs to have: moisture readings placed on your floor plan. Photos showing each spot tested. Lab results that name the mold found. Spore counts matched with outdoor air. A written cleanup plan signed by a MAC. If these are not in your report, then it does not follow Texas legal standards.

Homeyou tracked 1,977 inspections in Houston. Most cost between $313 and $389. Air samples add $150 to $300 each. A surface swab adds $75 to $150. A full inspection with more samples is about $500 to $900. Testing after cleanup costs $200 to $550.

One company charges a flat fee of $550 for homes up to 2,500 square feet. This price includes two samples. If you are looking for the cheapest choice, keep in mind that reports that are not finished and inspectors without a license can end up costing you more in the long run.

Reputation and Track Record

Google and Yelp reviews show if people got their reports when they should. They also say if the person came ready to start work. Pay attention to what people say over and over. If one hundred people talk about things being fast and clear, that is likely what you will get too.

For homes in Brays Bayou flood zones or in the Energy Corridor, including the Addicks/Barker release areas, ask the inspector: "Have you worked on homes here after Harvey?" The response is important. A person who has looked at Meyerland basements after water from the reservoirs will look at different places than someone who just follows a list used everywhere.

Moving Forward in Houston

The city will flood again. When this happens, call an inspector that same week. Do not wait until next month. Do not wait until you feel like you have time. Mold grows very fast. If you do early testing, you will have a smaller cleanup to do. It will cost less money and be safer for your health. After Harvey, the people who tested in the first week got ahead of all the others.

Get a TDLR-licensed assessor before you have a health issue or want to sell. It is less than other options.

Book a Houston inspection for same-day or next-day testing. We test only. No cleanup conflict.

Frequently Asked Questions

How soon after a flood should I call for testing?

You need to call for testing this week. The Houston heat can make things worse. Mold can start to grow in just 24 to 48 hours. By day 5 or 6, it can move deep into walls and under floors. Early testing helps you plan cleanup before it spreads all over. If you wait, you may end up paying more and have a harder job.

If I'm selling, do I have to tell you about mold? Yes. The Texas Property Code Section 5.008 says you have to tell about problems you know. Mold is one of those things. If you don't say anything and the buyer finds out after, you could face trouble with the law when the deal is done. A pre-listing inspection with a good report can help protect you.

What's the difference between a MAC and a cleanup contractor? MAC means Mold Assessor and Consultant. This person does tests and gives plans for cleanup. MRC means Mold Remediation Contractor. This person does hands-on work. In Texas law, one firm can't play both roles on the same job. If someone says they do both, ask them for two license numbers.

Why does post-Harvey Houston still have mold problems?
Many homes were rebuilt quickly. Drywall was put up before the floors had dried out. Because of this, water was trapped under the walls for months. The new drywall may look good and clean on the outside, but inside it is still wet. When humidity is at 75%, mold can grow very well.

What if I can't see any mold? Do I still need testing?

Yes, you do. Mold can grow in spots where people cannot see it. It can be in wall spaces, under the floors, or inside the HVAC pans. A moisture meter and air samples help to find mold before you see any stains. In Houston, the most common mold is the kind that is hidden from sight.

 

Key References

• Texas Occupations Code Chapter 1958 governs mold assessors and remediators

• TDLR Mold Assessors and Remediators Program maintains the license verification database

• CDC MMWR: Hurricane-Associated Mold Exposures After Harvey Houston, 2017

Houston Mold Inspection Cost Data from Homeyou 2026 project database