Is Mold Testing Worth It? When to Test (and When Not To)

If there's mold on your bathroom ceiling or behind the washing machine, you already know the most important fact: mold is growing there because something is wet. Both federal agencies that cover mold say the same thing:

• The EPA: In most cases, if visible mold growth is present, sampling is unnecessary.
• The CDC: CDC does not recommend mold testing, and suggests removing the mold and preventing future growth instead.
• Texas regulators agree. TDLR says it's generally not necessary to identify the species of mold growing in a residence, and that it's more important to find and eliminate the moisture source.

Why so firm? Because a test result rarely changes what you do. Visible mold gets removed regardless of its species, porous materials with growth get thrown out, and the leak gets fixed. TDLR also says testing to identify mold type is not required before remediation.

There's a second reason: there's no pass/fail number for a home. The EPA says there are no EPA regulations or standards for airborne mold contaminants, and the CDC says there are no set standards for what is and what is not an acceptable quantity of different kinds of mold. Mold spores are always present at some level, indoors and out. A report that says "mold detected" tells you almost nothing on its own.

When to test for mold, and when to skip it

Hidden mold you can smell but can't see

If your home smells musty but you can't find the source, an inspection is often worth it. A licensed assessor's real value is finding where the moisture is coming from. TDLR describes mold assessment as an inspection to evaluate whether mold growth is present and to what extent. Sometimes that means opening a wall: Fixr lists drywall removal for testing at $16 to $20 per square foot. See our guide to mold smell in the house.

Buying a home

A purchase is a one-time decision with a lot of money behind it, and you don't know the home's water history. An inspection can flag past leaks and active growth before you close. In Texas, sellers must give buyers a copy of each mold remediation certificate issued in the five years before the sale, so ask for those too.

Insurance, landlord and legal situations

When someone else may have to pay, documentation matters. A licensed assessor's report records what was found and where. If you rent, TDLR notes that current Texas law does not require landlords or property owners to inspect for or clean mold, so written evidence and written requests to your landlord matter. See mold in an apartment in Texas and does insurance cover mold.

Clearance after remediation

This is the one use of testing that both federal guidance and Texas rules support. The EPA says surface sampling may be useful to determine if an area has been adequately cleaned or remediated. In Texas, a licensed consultant checks that the area is free of all visible mold and wood rot and meets the criteria in the protocol. Passing leads to a Certificate of Mold Damage Remediation, which can protect you with insurers: an insurer may not make an underwriting decision based on previous mold damage or claims when the certificate shows the cause was fixed. See mold clearance testing.

This is where people spend the most on testing and get the least from it.

Mold can affect health. The CDC says damp and moldy environments may cause a variety of health effects, or none at all, including stuffy nose, sore throat, coughing or wheezing, burning eyes or skin rash. People with asthma or mold allergies may have severe reactions, and immune-compromised people and people with chronic lung disease may get lung infections.

But a mold test can't tell you whether mold is behind your symptoms. The CDC says you cannot rely on sampling and culturing to know whether someone might become sick. A doctor diagnoses illness, not a mold test. TDLR also recommends that people consult a health care provider if they are concerned about the effects of mold on their health.

If someone in your home has asthma, allergies or a weakened immune system, the practical answer is the same: find and fix the moisture, and get the mold removed promptly, with professional help for larger areas.

Kits are cheap, about $40 or less, and that's both their appeal and their limit. Most will show "mold" because spores are everywhere. TDLR says sample results cannot be interpreted without physical inspection of the contaminated area or without considering the building and what led to the problem. The EPA says sampling should be conducted by professionals experienced in designing sampling, collecting samples and interpreting results.

A kit can be a low-cost curiosity check. It can't find the leak, write a remediation plan, or produce a document an insurer or buyer will rely on. Our mold test kits guide compares kit types, and how to test for mold covers what you can check yourself with a flashlight and a moisture meter.

You may also see ERMI dust tests marketed online. The EPA calls ERMI a research tool that has not been validated for non-research purposes.

Typical mold testing prices

Insurance rarely helps: the Texas Department of Insurance says most home policies don't include mold cleanup and testing after a damaged item is removed. If you can see the mold, that money is often better spent on fixing the leak and the cleanup itself. Our mold testing cost guide breaks down every line item, and mold remediation cost covers the removal side.

1. Hire a licensed assessor. Texas law says no one may do mold assessment unless the person holds a mold assessment license. Check with our license check tool.
2. Keep testing and removal separate. Texas law says a license holder may not perform both mold assessment and mold remediation on the same project. A free test from a removal company is a sales tool, not an independent opinion.
3. Agree on what the results mean before sampling. TDLR says the consultant should establish criteria for interpreting the test results before remediation starts.
4. Ask what decision the test will change. If the answer is "nothing," skip it.

Find licensed mold testing companies in Houston, Dallas, Austin, San Antonio, Fort Worth, El Paso, Corpus Christi or Lubbock, or start at our Texas page. Every listing is checked against TDLR records; see how we verify.