How fast does mold grow after water damage in Dallas?

Fast. The Texas Department of Insurance's guide to water damage and mold coverage says mold can start growing within a day after a leak and tells homeowners to dry the area as soon as they can. The EPA's Brief Guide to Mold, Moisture and Your Home 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 window, in most cases mold will not grow. The EPA's flood cleanup guidance adds that when things remain wet for more than two days, they usually get moldy.

Those are the numbers to plan around. Days one and two are for stopping the water, removing standing water, pulling up wet carpet and pads, and getting air moving. Our first steps guide lists what to do, in order.

Moisture is the trigger. TDLR's mold consumer guide lists the common sources: pipe leaks, roof leaks, floodwaters, sewage backups and overflowing toilets, sinks and tubs. It recommends keeping indoor humidity no higher than 50 percent and using an air conditioner or dehumidifier during humid months. The EPA gives a similar target: below 60 percent relative humidity, ideally between 30 and 50 percent. A hygrometer to measure it costs about $10 to $50, according to the EPA.

Hidden spaces are the problem. TDLR suggests checking plumbing access areas, crawl spaces, behind mirrors and furniture, attics, closets and cupboards if you can see mold or smell a musty odor.

Both TDLR and the EPA draw the same line between hard and soft materials:

• Mold growth can be cleaned from non-porous surfaces such as concrete, metal, glass, tile and solid wood. The EPA recommends scrubbing with detergent and water, then drying completely.
• Mold is difficult to clean from porous materials such as drywall, carpet, upholstered furnishings and insulation. TDLR says these should be removed and discarded.
• Applying bleach to drywall without removing the source is not a permanent solution, and painting over mold is not effective either.
• Never mix chlorine bleach with cleaners that contain ammonia; the EPA warns this produces toxic fumes.

On size, the EPA says that if the moldy area is less than about 10 square feet, roughly a 3 foot by 3 foot patch, in most cases you can handle the job yourself. For more than that, or after a lot of water damage, it points to its professional remediation guidance.

Texas licenses both mold assessment (inspecting and testing) and mold remediation (removal) through TDLR. The state rules, as summarized in TDLR's consumer guide and mold FAQ:

Two TDLR rules protect you as a customer. The same company may not do both the assessment and the remediation on one project. And licensed assessors and remediators must give you the Consumer Mold Information Sheet before any mold-related work begins. Check any license in the TDLR license search.

Often not. TDLR says it is generally not necessary to identify the species of mold in a home, and that the CDC does not recommend routine sampling. Finding and stopping the moisture source matters more. If you do pay for testing, TDLR says the licensed consultant should set the criteria for interpreting results before sampling starts.

It depends on the cause. The Texas Department of Insurance says that if mold develops on an item damaged by a covered, sudden and accidental water loss, it would be covered, but most home policies do not cover damage from gradual leaks or seepage, including mold, and most do not include mold cleanup and testing after a damaged item is removed. For a mold claim, TDI says to make sure the mold professional has a state license, expect an inspection showing the mold was removed and the cause fixed, and get a certificate that the mold was removed. That document is the Certificate of Mold Damage Remediation (TDI Form MDR-1); on it, the remediation contractor certifies that the certificate was given to the owner within 10 days after completing the work. Only a licensed remediator can issue it. More on claims is in our insurance claim guide.

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