Water-stained drywall and baseboard in a Houston home after flooding, the kind of damp material that can develop mold within two days.

Mold After Water Damage in Houston, TX: What to Know

FEMA says wet materials can develop mold within 24 to 48 hours, and Texas law requires a license for most mold remediation work over 25 square feet, with exceptions for homeowners.

How Fast Mold Can Start After Water Damage in Houston

FEMA says wet carpeting, furniture, bedding, and other items that hold moisture can develop mold within 24 to 48 hours. Houston's warm, humid air slows how fast wet materials dry out, which is one more reason to get water out of a home as soon as it is safe to do so.

Why Houston's Heat and Humidity Raise the Stakes

Houston's Gulf Coast climate keeps outdoor humidity high most of the year. Warm, humid air holds more moisture and slows evaporation, so materials that got wet in a Houston home can take longer to dry out than they would in a cooler, drier climate. That does not change the 24-to-48-hour figures FEMA and EPA describe below; it is simply a reason drying speed matters here.

A musty odor in the room that was not there before the water event
Discoloration, streaking, or fuzzy patches on drywall, baseboards, or fabric
Paint or wallpaper that is bubbling, peeling, or feels soft

FEMA (Ready.gov): "Wet carpeting, furniture, bedding and any other items holding moisture can develop mold within 24 to 48 hours." See the FEMA flood fact sheet.
EPA: "In most cases, mold will not grow if wet or damp items are dried within 24-48 hours." See the EPA mold course.
CDC recommends drying wet materials fully and quickly within 24 to 48 hours after a flood. See CDC mold guidance.

For the broader picture of what to do right after water gets into a Houston home, not just the mold risk, see the Houston water damage overview.

Who Is Allowed to Remove Mold in Texas

Texas requires a TDLR license to perform mold assessment or mold remediation on most projects, under Occupations Code Chapter 1958. A company hired to do the work needs a mold remediation license once the project's mold covers 25 contiguous square feet or more; that area-based exemption applies to remediation, not assessment. Separately, an owner may assess or remediate their own residential property with fewer than 10 dwelling units, with no area limit. The table below lists the specific rules.

Texas Rule	What It Requires	Statute Section	Verified
License required for mold work	A TDLR license holder must do mold assessment or mold remediation work.	Occ. Code Section 1958.101	Checked: September 2026
Small-area exception (remediation only)	No license is required to perform mold remediation when the contamination on a project covers less than 25 contiguous square feet. This exemption does not cover mold assessment.	Section 1958.102(c)	Checked: September 2026
Owner-occupied exception	An owner may assess or remediate their own residential property with fewer than 10 dwelling units; this exemption has no area limit.	Section 1958.102(e)	Checked: September 2026
One role per project	The same license holder cannot act as both the mold assessor and the mold remediator on one project.	Section 1958.155(a)	Checked: September 2026
Certificate of mold remediation	The remediator gives the owner a certificate of mold remediation no later than the 10th day after the work ends. A seller must give a buyer certificates issued in the previous five years.	Section 1958.154	Checked: September 2026
Emergency notice to TDLR	In an emergency, the license holder notifies TDLR no later than the next business day.	Section 1958.153(b)	Checked: September 2026

You can read the full text in Texas Occupations Code Chapter 1958 on the state's official statutes site, and check a mold assessor's or remediator's license number directly with the Texas Department of Licensing and Regulation.

This is general information about Texas law, not legal advice. If you are not sure whether a project needs a license, ask TDLR or a license holder before work starts.

Houston, TX water damage restoration — Who Is Allowed to Remove Mold in Texas

What You Can Safely Do Yourself vs When to Call a License Holder

Texas law lets a homeowner work on their own home without a license, no matter the project's size, under the owner exemption. Whether that is wise for a large or heavily contaminated area is a separate, practical question. A company you hire needs a TDLR mold remediation license once the project's mold covers 25 contiguous square feet or more.

FEMA says to keep floodwater-contaminated materials separate and use protective clothing while you work.
EPA says unsalvageable moldy materials should be double-bagged in 6-mil-or-thicker plastic before you carry them out.
FEMA says people with asthma, lung disease, or immune suppression should not enter buildings with visible or suspected mold.

A company you hire needs a TDLR mold remediation license once the project's mold covers 25 contiguous square feet or more, regardless of whether the water came from a pipe, a flood, or a sewage backup. Floodwater and sewage carry their own contamination risks, which is a separate reason to be careful, not what triggers the license requirement. If the water came from a specific source, start with the cleanup steps for that cause: flood damage restoration steps for Houston homes or what to do after a burst pipe in Houston.

Does Homeowners Insurance Cover Mold After Water Damage

Homeowners insurance usually excludes mold except when it results directly from a covered water loss, like a burst pipe. Flood damage and slow, ongoing leaks are typically excluded, and sublimits for mold cleanup vary a lot by policy, so check your declarations page or ask your insurer what your specific mold sublimit is.

A sudden and accidental water release, like a burst pipe, is commonly covered.
Flood, continuous leakage or seepage, and mold beyond the repair needed for a covered loss are typically excluded.
Mold sublimits are not standardized in Texas; TDI-published endorsements have set them at 25%, 50%, or 100% of Coverage A.
If you rent, tell your landlord about the water and any mold in writing; your renters policy covers your belongings, not the building.

These points come from the Texas Department of Insurance's consumer guide to homeowners insurance.

This page is general information, not legal or insurance advice. For a coverage question specific to your policy, contact your insurer or the Texas Department of Insurance.

For the deadlines an insurer must meet once you file a claim, see how water damage insurance claims work in Texas.

Houston, TX water damage restoration — Does Homeowners Insurance Cover Mold After Water Damage

Questions to Ask a Mold Remediation Provider

Before you hire anyone for mold work, ask three things: their mold license number, who will act as the independent assessor, and whether you will receive a certificate of mold remediation when the work is done. A provider who cannot answer clearly is a reason to keep looking.

What is your mold remediation license number? You can verify a license number with the Texas Department of Licensing and Regulation.
Who is the independent mold assessor on this project? Under Texas law, the same license holder cannot do both the assessment and the remediation.
Will I receive a certificate of mold remediation, and by what date?
Ask the provider for proof of insurance and any trade license the job requires.

If a provider cannot name an independent assessor or will not commit to a certificate of mold remediation, that is a reason to keep asking around.

If That Did Not Work

If mold keeps coming back after you dry and clean an area, or a provider's answers do not add up, you have three next steps: recheck the moisture source, get a second, independent opinion, or find out who handles flood risk and water shutoff in your area.

Try again: make sure the moisture source itself is fixed. A slow leak behind a wall or under a slab will keep feeding mold no matter how many times the surface is cleaned.
Try another route: get an independent mold assessment before hiring a remediation company. Under Section 1958.155(a), the same license holder cannot perform both mold assessment and mold remediation on one project.
Who to contact: for flood risk, water shutoff locations, and reporting options in the Houston area, see Houston flood zones and how to shut off your water.

Houston, TX water damage restoration — If That Did Not Work

What Changed on This Page

September 2026: page published; phone numbers and legal deadlines checked against the official sources linked above.

Frequently Asked Questions

How fast can mold start after water damage in a Houston home? ▾

FEMA says wet carpeting, furniture, bedding, and similar items can develop mold within 24 to 48 hours. The EPA says mold generally will not grow if wet or damp items are dried within that same 24-to-48-hour period. Houston's warm, humid air slows how fast wet materials dry out compared with a cooler, drier climate.

Do I need a license to remove mold in my own house? ▾

Usually not. Under Texas Occupations Code Section 1958.102(e), an owner can perform mold assessment or remediation on their own residential property if it has fewer than 10 dwelling units, with no square-footage limit on the exemption. This exception covers the owner doing the work themselves, not a business performing the same work for the public.

How small does a mold job have to be to skip the license requirement? ▾

Under Section 1958.102(c), mold remediation does not require a license when the contamination on a project covers less than 25 contiguous square feet; this exemption does not cover mold assessment. At or above that size, Section 1958.101 generally requires a license for both mold assessment and mold remediation.

Can the same company both assess and remove mold on my project? ▾

No. Section 1958.155(a) of the Texas Occupations Code says a license holder may not perform both mold assessment and mold remediation on the same project. Ask who the independent assessor is before you hire anyone for the remediation work itself.

What is a certificate of mold remediation, and when do I get one? ▾

It is the document a mold remediation license holder must give the property owner under Section 1958.154, no later than the 10th day after the work is finished. If you later sell the house, you must give the buyer certificates issued in the previous five years.

Does homeowners insurance cover mold after water damage? ▾

Usually only as part of a covered water loss, like a sudden pipe burst. Flood, ongoing leaks, and mold beyond that necessary repair are typically excluded under most standard Texas policies, and sublimits for mold cleanup vary by policy and endorsement. Check your declarations page or ask your insurer what your specific mold sublimit is.

Do I have to give a home buyer my mold remediation records? ▾

Yes. Under Section 1958.154(b), when you sell the property you must give the buyer copies of any certificates of mold remediation issued during the five years before the sale. The remediator gives that certificate to the owner no later than the 10th day after the work is finished, under Section 1958.154(a).

Water in your home right now?

See who to call first in Houston, how to reach your water provider, and how to check your flood zone.

Who to Call First in Houston