Mold After Flooding in Houston

Move Immediately

Mold growth generally begins within 24 to 48 hours of material becoming wet. In a Houston summer, with a house full of standing water and no power, it can be faster.

Extraction and drying in the first two days prevents problems that otherwise take months and tens of thousands of dollars to resolve. This is the highest-leverage period you will have.

Document Before You Touch Anything

Photograph and video everything before removing a single item — the water line on the walls, every affected room, damaged contents with model numbers visible.

Once demolition starts the evidence is gone permanently, and insurance and FEMA claims both depend on it. Five minutes with a phone camera is worth thousands.

What Has To Go

Floodwater Is Not Clean Water

This is the distinction that changes the response. Floodwater from outside is category three — it carries sewage, chemicals, and biological contaminants regardless of how clear it looks.

Porous materials touched by floodwater generally cannot be cleaned and returned to service. That is a different standard than a burst supply line, where more material can often be dried and saved.

Drying That Actually Works

Removing standing water is the beginning, not the end. Framing, subfloor, and remaining assemblies must be dried to verified moisture content, which takes days of air movement and dehumidification.

Closing walls before framing is dry builds the next mold problem into the repair. This is the most common failure in post-flood work, and Katy is full of homes where it happened in 2017.

Insurance Reality

Standard homeowners policies do not cover flood. Rising surface water requires separate flood insurance through the NFIP or a private carrier.

If you have flood coverage, mold resulting from the flood may be addressed under it, subject to its terms. If you do not, the homeowners carrier will almost certainly deny a flood-caused mold claim.