Mold Remediation in Houston, TX

Mold needs moisture, a food source and warmth, and Houston supplies all three. Relative humidity averages about 75% through the summer and sits above 90% in the early mornings (NCEI climate normals). There's no dry season: every month normally brings 3 to 6 inches of rain (NWS). Any water that gets in and isn't dried within 24 to 48 hours is likely to grow mold (EPA), and after Harvey, Beryl and the 2024 derecho, thousands of homes sat wet and without power for days.

Indoors, the usual culprits are a clogged AC condensate line soaking a ceiling, an air handler closet that never dries out, a slab leak nobody noticed, a slow leak under a sink, and attics and exterior walls where pipes burst in the 2021 freeze and the drywall was patched before the framing was dry.

Texas regulates mold assessment and remediation through the Department of Licensing and Regulation (TDLR). Four rules matter to a homeowner:

• A license is required. Nobody may do mold assessment without an assessment license, or mold remediation without a remediation license (Texas Occupations Code 1958.101).
• The small-area exemption. A license isn't needed where the contamination is less than 25 contiguous square feet (1958.102). Above that, it is licensed work.
• No assessing and remediating the same project. A license holder may not do both on the same project, and nobody may own an interest in both companies on the same project (1958.155). The rule exists so nobody can find mold and then sell you the fix.
• You get a certificate. Within 10 days of finishing, the remediator must give you a Certificate of Mold Damage Remediation, including a licensed assessor's statement that the contamination was remediated as the protocol required (1958.154). Keep it: when you sell, buyers are entitled to copies of certificates from the past five years.

Before anyone starts, ask for the license number and check it on the TDLR license search. For patches under 25 square feet on hard surfaces, our guide to cleaning a small patch covers what to do.

1. Find the water. Moisture meters and thermal imaging locate the leak or condensation that fed the mold. Removing mold without fixing the moisture just restarts the clock.
2. Protocol. For licensed jobs in Texas, a licensed assessment consultant writes the remediation protocol: what to remove, where, how, and what "clean" will mean at clearance (16 TAC 78.100).
3. Contain the area. Plastic sheeting and negative air pressure stop spores spreading to the rest of the house, with HEPA air scrubbers running.
4. Remove what can't be cleaned. Moldy drywall, insulation, carpet pad and ceiling tiles are cut out and bagged. EPA guidance is that porous materials with mold growing in them generally have to be discarded (EPA).
5. Clean hard surfaces and dry. Studs, concrete and other hard materials are cleaned and, where appropriate, treated, and the area is dried to match the rest of the house.
6. Clearance. A licensed assessment consultant, not the remediator, inspects while the containment is still up and issues a passed clearance report; the remediator then gives you the certificate and before-and-after photos within 10 days (16 TAC 78.140; 78.150). See mold inspection and testing in Houston.
7. Rebuild. New drywall, paint and trim, often with mold-resistant board in bathrooms and laundry rooms.

Published national ranges run from about $1,200 to $9,000 depending on the source, with averages between $2,300 and $3,500 and per-square-foot figures of roughly $10 to $30 (Fixr, 2025; This Old House, 2026; Bob Vila). The spread is about size and access: a closet wall is at the low end, an attic, a whole air handler system or a post-flood ground floor at the high end. In Texas, licensed jobs also carry the assessor's protocol and clearance fees, which buy you an independent sign-off.

Insurance usually covers mold only when it follows a covered water event (a burst pipe, for example) and often with a cap; mold from humidity or a long-neglected leak is usually excluded. The estimate comes in writing before any work starts.

The CDC's summary: for some people, mold can cause a stuffy nose, sore throat, coughing or wheezing, burning eyes or a skin rash; people with asthma or mold allergies may have severe reactions, and people with weakened immune systems or chronic lung disease can get lung infections from mold (CDC). If anyone in the home is in those groups, don't disturb the mold yourself; have it removed, and keep them out of the area until it's done. You don't need to know the type of mold, and the CDC doesn't recommend testing to decide whether to clean it up.

• Mold covering more than about 10 square feet (the EPA's do-it-yourself limit); above 25 contiguous square feet it's licensed work in Texas
• Mold that came back after cleaning
• A musty smell with no visible source
• Mold after a leak, flood, freeze or AC overflow
• Someone in the home with asthma, allergies or a weakened immune system

Call (346) 699-3911 and we'll connect you with local mold remediation help. If the mold followed water damage that hasn't been dried, start with water damage restoration in Houston.