Mold Testing in Houston, TX

Start with the question you want answered

A lab report is only useful if it answers something specific. Before you book, write down what you are trying to learn. Good reasons to test in Houston include:

• A persistent musty smell, often strongest when the AC kicks on, with nothing visible on walls or ceilings.
• A leak or storm intrusion you dried late, where you suspect growth inside a wall cavity or under flooring.
• Comparing indoor air to outdoor air so you know whether indoor spore levels look unusual.
• Documenting conditions before a remediation project, so the clearance check later has something to compare against.

If there is a dark patch spreading across the drywall under a bathroom window, you don't need a lab to confirm it. You need the water source found and the material dealt with.

What the sampling looks like

Expect the assessor to walk the house first, use a moisture meter, and look at the air handler, drain pan and supply registers, since Houston's long cooling season keeps that equipment damp for months. Then come the samples. Air samples pull a measured volume of air through a cassette, usually with one taken outdoors for comparison. Swab or tape samples lift material from a surface to identify what is growing there. Some assessors add a sample at the HVAC system. Ask how many samples are planned and why each one is needed.

Reading the results honestly

There are no EPA or federal limits for mold or mold spores, so no report can declare a number "safe" or "unsafe." What results can do is show whether indoor counts are well above outdoor counts or whether a particular type is concentrated in one room. The color of a mold says nothing reliable about how risky it is. If anyone in the house has asthma or a weakened immune system, keep them away from moldy areas and talk to a health professional about any health concerns.

Who can test, and what it costs

You may take samples in your own home without a state license. Anyone you hire to test must hold a TDLR mold assessment license, and you can check the name on TDLR's license search. The Houston Health Department does not test homes for mold; it refers those requests to TDLR. One more Texas rule matters: if testing leads to a remediation project, the company that writes the protocol cannot also do the removal on that project.

Price moves with house size, the number of samples, lab turnaround and how hard spaces like the attic are to reach.