This Mold House redux: Discussing mold never gets old

NolaVie editor Renee Peck wrote This Mold House for The Times-Picayune for four years after Hurricane Katrina. She is reposting a number of her favorite columns in conjunction with the 10th anniversary of the storm. This article originally was published in The Times-Picayune InsideOut section on Jan. 14, 2006.

“But we only got 8 inches of water,” Stewart kept saying as we surveyed molds in a panoply of varieties, hues and textures crawling across the walls and ceilings and into the air ducts of our East Lakeshore home.

“Eight inches, 8 feet, with mold it doesn’t matter,” replied the first of a series of workmen who come and go through our family like stray pets. We try to adopt them, but life on some other street invariably calls.

After a career that has involved covering food, TV, parenting issues, local entertainment, the Internet and interior decor, I never saw myself as The Times-Picayune’s mold writer.

Now I’ve spent four months in at-home and on-the-job training.

I’ve talked to professional industrial hygienists on both coasts and states in between. I’ve interviewed government mold experts and licensed mold remediaters and attended mold workshops. The Google home page on my computer goes automatically to “mold,” without prompting.

And I’ve discovered that mold is pretty gross stuff. It may, in fact, give the cockroach a run for its money.

A live mold spore can live behind your walls for more than a decade, waiting for a stray drop of water to help it pop to life.

A dead mold spore contains the same toxic properties as a live one, meaning that it can sit in your carpet or behind your air vent waiting to start a sneeze or coughing fit.

Until they grow into that billion-member colony that looks like cotton candy on your Sheetrock, mold spores are invisible — typical size is 2 to 20 microns. To get a sense of how tiny that is, consider that you could fit 20 million 5-micron spores on a postage stamp.

Like us, molds need water and food for sustenance. They love to eat leather, starch adhesives and anything that contains paper (like your cellulose-filled drywall or insulation).

But for my family, the worst thing about mold is the smell. Slightly sweet and cloying, it lingers not only in the nostrils, but in the brain.

“There’s something moldy in this car,” Stewart will say as we drive to the Palace for a movie.

“You brought something moldy in here, I can smell it,” he said in our Uptown apartment after a recent trip to our driveway POD storage unit.

“I am not,” I retort, “that stupid.”

Mold, you see, has become our Katrina icon: It is death and loss and destruction.

And it will be around for long months to come.

BRUSH-UP ON MOLD

This is remedial reading for those of you who, like me, have become pros at gutting drywall and spraying bleach and water on plaster. But for those just starting the process, here are some things about mold worth knowing, all gleaned from interviews I’ve reported.

• Mold, which is a fungus, is a naturally N’Awlins kind of thing: We have thousands of varieties in the local environment. What you don’t want is to have more spores inside your house than outside.
• In Louisiana, professional mold remediators must be licensed. For a list, see www.lslbc.state.la.us/search/cresults.asp. Mold remediators cannot, in this state, conduct post-clearance tests on their own remediation efforts to document spore counts.
• Mold can be cleaned from nonporous surfaces, such as granite or glass, but not from porous ones, such as drywall or carpets. Semi-porous substances, such as wood, often can be cleaned.
• The recipe for mold remediation is “clean, then disinfect.” Clean any visible mold with detergent, then disinfect with a solution of a half cup of bleach to a gallon of water.
• Mold infestation requires drastic measures: Moldy drywall and any wet insulation behind it must be removed. Studs must be cleaned, disinfected and, if necessary, shaved or wire-brushed to remove mold. Plaster walls can be saved, unless there is wet insulation behind them.
• Drywall should be removed at a height of at least 2 feet above the water line. A “flood cut” at 4 feet is common, since drywall comes in 4-foot sheets that can then fit into the opening. But remember that the mold you see on the outer walls is probably half of what’s behind them. Water “wicks” up to higher levels inside the cavities, and mold colonies follow.
• Drying is paramount to success. Studs should contain less than 20 percent moisture (some experts recommend under 16 percent) before walls are closed. Invest in a pronged hygrometer, or moisture meter, that you stick into the wood to test it yourself.
• Cleaning mold without the proper attire is like skydiving without a backup chute. My N-95 twin cartridge respirator has replaced the muddy soccer cleats and stray homework pages in the passenger seat well of my car.

DOING IT MY WAY

I probably went overboard on mold cleanup, but everyone in my family has an allergy or three. Anyone who sneezes at the sight of a dust ball or has a suppressed immune system can be particularly sensitive to potential mycotoxins in mold. Basic drywall gutting runs $2 or $3 a square foot; professional mold remediators cost three or four times that. We felt the peace of mind was worth the cost.

Here’s what licensed local company Aire-Scrubbers did at my house over the course of eight work days, with a crew of four:

• Around-the-clock operation of commercial negative air pressure differential machines (“air scrubbers”) to remove airborne spore particles.
• Around-the-clock use of industrial dehumidifiers to dry the environment.
• Removal of all drywall — and ceilings — downstairs and one mold-infested room upstairs.
• Cleaning and wire-brushing of each exposed wooden stud.
• High efficiency particulate air (also know as HEPA) vacuuming with a commercial vacuum that goes over floors, wall cavities and studs.
• Application of an Environmental Protection Agency-approved latex-based bio-growth inhibitor to all exposed wood. This keeps any embedded or overlooked spores from reproducing.

The professional air quality inspector who measured spore counts afterward found the indoor mold count to be 259 per cubic meter, well under the 1,300 that designates a building “moldy,” according to the National Allergy Bureau. Better yet, the indoor air-spore count was 93 percent lower than the outdoor count. While there are no national numerical standards that decree what spore levels are “safe,” the indoor air count should be a third or less of the corresponding outdoor count.

For more information on mold see www.epa.gov/mold/index.html or www.buildingscience.com.