Mold After a Water Leak? When to Call a Pro

Mold needs moisture. The EPA's brief guide to mold and moisture says the key to mold control is moisture control, and that if wet or damp materials are dried within 24 to 48 hours after a leak or spill, mold usually will not grow. That clock starts when the water arrives, not when you first notice a musty smell.

So the first job is to stop more water. Shut off the fixture or the main water valve for a burst pipe or water heater leak, empty a clogged sump pit once it is safe, or get a roof leak tarped. Our toilet overflowing, roof leaking during rain and ice dam guides cover those emergencies. Then remove standing water, open windows if outdoor air is drier, and start drying with fans and a dehumidifier aimed at the wet zone.

Do not run the furnace or central air to dry the house if you think the ductwork or air handler got wet or already has mold. The EPA warns that running a contaminated HVAC system can spread mold through the building.

CDC describes mold as spots of many different colors with a musty smell, and says mold grows where there is moisture around leaks in roofs, windows or pipes, or after a flood. It grows on paper, cardboard, ceiling tiles, wood, drywall, carpet, fabric, insulation and dust. You may first notice black, green, white or gray patches on baseboards, behind vinyl wallpaper, on the back of a closet, or a musty smell in a basement that never quite dried after a spring thaw.

Older homes in Indiana, Blairsville, Homer City, Greensburg, Latrobe, Jeannette, Mt Pleasant and Murrysville often have unfinished basements, plaster or drywall on exterior walls, and carpet or paneling over concrete. Those finishes hold water after a sump failure, sewer backup, ice dam drip or burst pipe, and mold can start in the wall cavity days before it shows on the face of the drywall.

You do not need a lab test to decide what to do. CDC does not recommend routine mold testing in homes, because cleanup is the same for common indoor molds and there are no federal standards for how much mold is acceptable indoors.

For a small area of mold on a hard, non-porous surface after clean water, EPA and CDC both say you can often clean it yourself. Wash the mold off with detergent and water, then dry the surface completely. CDC also describes a bleach solution of no more than 1 cup of household laundry bleach in 1 gallon of water for hard surfaces, with windows open, rubber gloves, boots and goggles, and a clear warning never to mix bleach with ammonia or other cleaners.

Throw out ceiling tiles, soaked carpet pad, cellulose or fiberglass insulation and other materials that stay moldy or cannot be dried. EPA notes that absorbent materials such as ceiling tiles and carpet that become moldy may have to be replaced. Wallboard may dry in place if there is no swelling and the seams are intact; otherwise it should come out so the cavity can dry.

Keep children, pregnant people and anyone with asthma or a weakened immune system out of the work area. EPA's flood cleanup guidance says people with breathing problems or weakened immune systems should stay away from moldy sites and should not take part in heavy cleanup.

EPA says to bring in experienced help when mold covers more than about 10 square feet, when the water was sewage or otherwise contaminated, when you suspect the HVAC system is involved, or when you have health concerns. A finished basement that stayed wet for days, a whole wall of stained drywall, or a musty smell that returns after you wipe the surface are common Western Pennsylvania cases that need more than a sponge.

Sewage backups and muddy flood water from creeks and storm drains around Indiana, Blairsville and Latrobe are not DIY jobs. Contaminated water needs personal protective equipment, containment and disposal methods a restoration crew is set up for. The same is true when water wicked high into wall cavities, soaked attic insulation after a roof leak, or sat under a floating floor.

A water damage restoration provider can measure moisture in walls and floors, set up commercial air movers and dehumidifiers, remove what cannot be saved and document the work for your insurer. Ask them to separate the drying and mold cleanup scope from any rebuilding so each part of the claim is clear.

Before you tear out wet materials, take dated photos and short videos of the leak source, the wet materials and any visible mold. Call your homeowners insurer, ask what documentation they need, and ask whether mold cleanup is limited by a sublimit on your policy. Keep every receipt for emergency drying, temporary repairs and equipment rental.

Pennsylvania home improvement contractors who do more than $5,000 of work a year must register with the Attorney General. Ask for the contractor's HIC number, verify it on the Attorney General's online search, and get a written contract that lists the moisture source, the materials to remove, the drying targets and the price. Be wary of anyone who promises a free mold inspection that leads straight into a high-pressure sale, or who wants a large cash deposit before work starts.

If the original leak was a roof, plumbing or HVAC failure, fix that cause as part of the plan. Cleaning mold without stopping the leak is temporary at best.

CDC notes that mold can cause a stuffy nose, sore throat, coughing or wheezing, burning eyes or a skin rash, and that people with asthma or mold allergies may have more severe reactions. Immune-compromised people and people with chronic lung disease can get lung infections from mold. If anyone in the home has those conditions, talk with a health professional before starting cleanup and lean toward hiring a crew.

During cleanup, wear an N95 respirator if you have one that fits, gloves and eye protection, and ventilate the area. Do not use ozone generators or fogging products as a substitute for removing moldy materials; EPA focuses on fixing moisture and physically removing the growth.

After the work, watch for a returning musty smell, new stains or condensation on cold basement walls. Keep indoor humidity as low as you reasonably can, ideally no higher than about 50 percent, with a dehumidifier in damp basements common across Indiana County and Westmoreland County.