Why the EPA says to dry wet areas within 24 to 48 hours, when a mold job is small enough to handle yourself, and what changes after a flood.
By the WaterDamageRated team · Facts checked against the sources listed below on November 1, 2026. General information, not professional advice.
The US Environmental Protection Agency (EPA) says it is important to dry water-damaged areas and items within 24 to 48 hours to prevent mold growth, and that if wet materials are dried within that time, in most cases mold will not grow.
EPA says that if the moldy area is less than about 10 square feet (roughly a 3 ft by 3 ft patch), in most cases you can handle the job yourself. Where there is a lot of water damage, or mold covers more than 10 square feet, EPA says to consult its guide Mold Remediation in Schools and Commercial Buildings, and that you may choose to hire a contractor.
EPA's disaster guide says that if you could not dry your home and belongings within 24 to 48 hours, you should assume you have mold growth. It warns against using fans once mold has started to grow, because they may spread it, and says painting or caulking over mold will not stop it.
The IICRC S500 Standard for Professional Water Damage Restoration describes the procedures and precautions for water damage restoration; the current edition is ANSI/IICRC S500-2021. On this site, “IICRC certification stated” means a company says so on its own website; ask for the certificate if it matters to you.
No. It is EPA's guidance on when a job is usually small enough to do yourself. Licensing rules are separate: Texas, for example, exempts mold projects of less than 25 square feet from its mold licensing rules.
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