The Mechanics of Mold


By Jacob Passy, Ashley Rodriguez, and Emilie Ross

May 13, 2014
New York, NY

Abigail Javier is always cleaning her bathtub. The mother of four lives with her husband and two sons in the Jefferson Houses in East Harlem. She called the New York City Housing Authority about the mold and mildew in her bathroom more times than she can count over the past ten years. When the workers come, Javier hides her dogs and birds to keep them from the “poisonous” bleach she smells wafting through her apartment.

Three or four months later the mildew is always back. And Javier ends up scrubbing the walls with Tilex.

“It keeps on coming back,” said Javier. “All year 'round. When I see the wall start to turn colors, I scrub. I can’t let it takeover.”

Javier, president of the Jefferson Houses Tenant Association, suspects poor ventilation is to blame for the growth in her bathroom. But she says her apartment doesn’t compare to others in the 1,487-unit housing complex that have mold in their bedrooms and kitchens.

Older structures like the Jefferson Houses, built in 1959, are increasingly susceptible to mold growth, because they often have poor ventilation, outdated plumbing and structural damage. Residents may live for days, weeks, or years among unsafe mold, while they a wait for the costly and time consuming repairs.

So how do you know if you have mold in your apartment? And more importantly, how do you get rid of it, for good?

The Spread of Mold

Before you can treat mold, you need to know where to find it.

Mold grows best in the warm, damp conditions created by steamy showers, dripping pipes, and leaky ceilings. Public housing residents are especially vulnerable to these conditions because they don't have control over their heating and plumbing. In this environment, mold spores reproduce quickly, spreading throughout an apartment or building.

Video Courtesy of Cornell University Plant Pathology

The fungi growing on this bagel is similar to the mold that is commonly found in homes and apartments. However, it is not the black mold that can cause serious health effects.

“Under the right conditions even tiny mold colonies can be visible to the naked eye,” said industrial hygienist Bill Sothern from Microecologies. “These can develop in as little as 72 hours.”

However, mold often lingers behind the walls in an apartment, so residents may not even know they have a mold problem.

“Mold can be difficult to locate and identify,” said Sothern. “Wet conditions inside a wall can create the ideal conditions to support mold growth.”

Discoloration, cracked or peeling paint, and bulging walls, floorboards and ceilings are signs that mold could be hiding out of sight, according to a 2006 report by the Public Advocate for the City of New York.

Mold may start in a damp basement, traveling up the building’s structure; or work its way down from the ceiling where there's a leaky roof or pipe. Spores love wood and dry wall, which is usually where you'll find them. Tiles, furniture and carpets are other common surfaces where mold and mildew grow, according to the U.S. Department of Housing and Urban Development. Air ducts and heating systems can also help spread mold by carrying the spores from one room to the next.

Once you find mold, it's important to act as quickly as possible. The more the mold spreads, the harder it becomes to truly eliminate it.

“Acting quickly can mean the difference between a quick repair and an extensive remediation project,” said Sothern.

Peeling paint
By Gabriella Iannetta

“It's not fixed, they don't come and fix it,” said handyman Frankie Negron, 31, in his uncle's Jacob Riis apartment. “Look, they came two months ago and the paint's already peeling.”

Negron broke off the yellow-stained paint from the walls to show a bumpy, moist residue underneath: mold. The paint chip, about a foot long, snapped off the wall easily. Negron shook his head.

“Don't break off all my paint!” Negron's mother, Annette Negron, 52, yelled.

“It makes no difference,” Negron said. “It's just going to get worse again.”

Annette Negron first complained about their mold-infested walls in the spring of 2013. Since then, she said, NYCHA inspectors have come to the apartment three times; the second time maintenance simply wiped the walls with a bleach mixture. Maintenance returned in February to paint over the mold—and not surprisingly, it came back. By late April, paint was cracking on the walls of the hallway and bathroom.

“I feel how musty it is,” Negrone's mother said. “It never left.”

Getting Rid of Mold

Mold is not generally something people know much about or think about until they are forced to deal with it.

On the surface, it looks awful, dirty. Mold is even more insidious because it often grows unseen behind walls, and spreads spores that are invisible to the naked eye.

In the desperate attempt to rid their home of mold, people often end up acting on faulty information or misconceptions. Many simply wipe up the mold with bleach or paint over it — and figure the problem is gone.

But it isn't.

If the source of the mold isn't dealt with, it invariably rears its head again, as resident after resident has discovered.

“It's a classic landlord-tenant situation: bleaching and repainting the ceiling of the bathroom. It will come back because the underlying moisture source wasn't fixed. In a bathroom, that's usually humidity and condensation,” says James Mallory, the owner of Environix, a Lynnwood, Washington-based indoor environmental company. “Mold remediation is totally worthless unless you fix the underlying moisture problem.”

The New York City Housing Authority seems to understand that, judging from its website's tips andsuggestionson mold prevent and cleanup.

“Removing the source of moisture — by repairs and by providing sufficient ventilation — is critical to preventing mold growth,” NYCHA tells its residents on the site.

How do you remove the source? NYCHA offers up the “Fresh Air Cure”: Open up your windows and keep the apartment well ventilated.

NYCHA also urges residents who find mold to act quickly. NYCHA's recommended methods: Use appropriate household cleaners, preferably those labeled “antimicrobial,” and make sure that whoever does the cleaning does not have a cold or is not prone to allergies or asthma.

Finally, NYCHA adds, if the problem persists, call its customer contact center.

Are NYCHA's recommendations enough? Our reporters asked three mold remediation experts.

Like NYCHA, the experts urge residents, most of all, to take preventive measures to keep mold from surfacing. “I can't stress enough maintenance,” says Jeffrey Sindone, vice president of Moldbusters, a New York-city-based mold remediation company. “Any air leakage in the building, any moisture intrusions — being aware of that, that's the best advice I can give. Catching it before it happens is the key thing.”

How to spot mold

Poor ventilation and leaks within the walls can lead to a mold infestation that could turn an eyesore into a serious health problem. “If these conditions exist then there is a high likelihood for mold growth to occur,” said Bill Sothern of Microecologies, a mold-removal service. In these cases, it's important to know where to spot mold in your apartment and how to treat it. Use this floor plan to find problem areas where your apartment may develop mold. To see photos and descriptions of mold growths, click on the colored buttons.

Apartment diagram image courtesy The Home Sitter via Google Images Creative Commons

But once mold has started to spread, here's how the experts tackle the problem:

Before remediation, conduct a thorough inspection

A professional should first establish the level of mold spores in the air and the exact locations where mold is growing. This can be done through spore trap analysis, (using a device that captures particles in the air on a sticky surface which is then sent to a laboratory for analysis), and use of an infrared camera that detects heat, cold, and relative humidity in order to inspect behind walls.

The following questions should also be answered:

  • Is there moisture or high relative humidity? Where and why?
  • Is there specific water damage that happened? Where and why?

Wipe the mold away

Physical removal of mold is the next step. A nonporous surface, like the sheet metal in an air duct, can be cleaned with a water-and-detergent solution and a rag.

If mold is growing on anything porous, then that material needs to be discarded, because it is extremely likely that mold is growing on the inside of the substance. These materials include sheetrock, wood, cardboard, drapes, upholstered furniture — essentially anything that can absorb moisture.

Semi-porous surfaces — like wood products — generally need to be roughed up with sandpaper, a wire brush, or media blasting.

Standard mold cleanup protocol involves the following steps:

  • HEPA (High-Efficiency Particulate Air) vacuuming.
  • Antimicrobial treatment, such as wet wiping or fogging, (use of a device that distributes a fine mist of anti-microbial chemicals that coat the space).
  • Encapsulation of wood with antimicrobial paint spray to seal it to prevent future mold growth.
  • Containment of the area where the remediation work is being done by setting up plastic barriers. Otherwise, cross-contamination will occur in other parts of the residence. When workers open up a wall, moldy material goes airborne.
  • Air scrubbers and commercial dehumidifiers should be running the whole time that work is being done.

Credit: Nancy Torres 2013

Fixing what lies beneath

But cleanup won't stem the underlying moisture problem that caused the mold to grow in the first place. If water is entering the home through a leaky roof or pipe, then that must be fixed. If humidity is too high, better ventilation and exhaust systems must be installed to keep humidity under 50 to 55 percent. This can be measured with a wall-mounted relative humidity gauge, which costs about $30.

Follow up

Air testing should be repeated after the remediation process is complete, again using spore trap analysis.

Ensuring a lack of moisture is key in preventing a return mold. Low humidity levels and good air movement are essential. Air conditioning can help prevent mold growth.

Any plumbing or a roof leaks should be fixed within 72 hours. The drying out of wet surfaces should begin within 72 hours to prevent mold growth, according to the industry standard.

What can go wrong?

There seems to be some disagreement in the mold remediation community over the use of bleach. Bleach works well on non-porous surfaces, like tile, granite, or stone. But if you apply bleach to sheetrock or wood, it can actually make the problem worse because it is water-based. Experts are at odds on how serious this introduction of water is to mold-tainted porous material.

“There's debate about whether chemicals need to be used for remediation projects or not. Some say there’s no need, some say every project, and everywhere in between. You're dealing with an air quality issue, and anti-microbials must be registered as a pesticide. The concern is that the resulting air quality becomes worse,” says Ian Cull, owner of Indoor Sciences, a training and consulting firm in Chicago. “It's a complex, very contentious topic.”

Applying chemical treatments to surfaces is evidently not foolproof, according to the experts. Yes, the treatments will prevent mold growth on the material itself. But mold can grow on the layer of dust that gets deposited over time on the material. In a bathroom, for example, dust, skin cells and soap scum will accumulate over time on the walls, creating a layer of grime that the mold can use as food. So keeping surfaces clean is very important.


What the tenant or resident can do

The complexity of fixing a mold problem begs the question: Can residents “do it themselves?” Cleaning surface mold might be okay, but experts draw the line at the physical removal of contaminated materials. A speckling of mold can be cleaned with a paper towel and detergent solution, but cutting out sheetrock requires professional expertise to prevent cross-contamination and exposure to the tenant.

What next?

Under the terms of a settlement announced in December 2013, NYCHA has pledged to respond to so-called “simple” repairs, such as cleaning up the mold, fixing dripping water faucets or repairing a window that does not operate properly within seven days. NYCHA must address work that requires a skilled trade worker, such as a plumber or a roofer, within an average of 15 days.

NYCHA said in email responses to questions that it is providing residents and staff with material about mold in its publications and on its website. The agency also said that it has recently intensified its efforts to train staff to better identify the sources of moisture responsible for mold.

In addition, the agency also has given tenants a short handout about controlling, preventing and cleaning mold, and says it is “working to inform residents and staff about the need for ventilation, whether it is ensuring that roof fans and ventilation systems are working properly, or windows are open to allow fresh air needed to keep the units mold-free.”

But experts point out that several of the common-sense recommendations NYCHA offers may prove impossible for some tenants to follow. The suggestion that they open bathroom windows, for example, is impossible if there is no bathroom window. Keeping the apartment dry is not necessarily up to the tenant if a leak is coming from above them.

NYCHA's recommendations end in a suggestion to call its customer contact center if nothing else works. In an email, NYCHA wrote that the calls are “our best way of knowing when there are problems. If mold returns, residents are told to call back. Reoccurring mold may be due to the underlying condition being incorrectly identified or it may be due to a different issue. Staff will return and reassess.”

Once work is done, NYCHA reports, the agency plans to begin assessing apartments and following up on work orders.

NYCHA tenants are skeptical. A team of reporters visited the Jacob Riis houses on the Lower East Side and the Jefferson houses in East Harlem in late April and interviewed more than 30 residents who said repeatedly they do not receive timely or adequate help after reaching out to NYCHA for assistance. At least a third of those interviewed reported that NYCHA workers came to remove mold in their apartments by simply wiping it up or painting over it.

Inspect the Mold Yourself

Mouse over image to zoom in.

“They come, wipe it down and paint over it, but that's not how it's fixed,” said handyman Frankie Negron, who helps his disabled uncle, a Jacob Riis houses resident.

Over and over again, the mold just keeps coming back, tenants say.

In its email response, NYCHA said its policy is to remove mold and repaint the surface, though what happens next can vary.

“Unfortunately, even when the mold is removed, it usually leaves a stain that people sometimes assume is mold,” the agency wrote. “Generally when mold returns in these situations, it is because the underlying cause has not been identified and addressed.”

Never ending battle
By Emilie Ross

Francesca Santiago, 40, has lived in her fourth floor apartment at the Jefferson Houses in Harlem for 18 years. Walking into her apartment, you are struck by the cheeriness of it. There are toys everywhere for her grandson Merrik, 2, to play with, and colorful walls—warm coral pink in the living room and a cool aqua in the kitchen. It smells like laundry.

“I try to make it smell clean, to hide the odor,” Santiago said.

She's talking about the mold that keeps growing in her bathroom, under her sink, and in her living room. At the base of the walls near her front door, the paint is starting to blister and crack from dampness.

“It's horrible. It's horrendous. If you don’t do something you start to feel sick,” Santiago said. “I don’t bring company at all. It's embarrassing.”

By Santiago's estimation, she overhauls her apartment twice per year. With the help of a reliable friend, she cleans off the mold, and re-plasters and repaints her walls.

Santiago is a former NYCHA employee who worked at the call center that took incoming repair tickets, so she has seen first hand how futile it can be for tenants to turn those tickets into results.

“Plastering. It's like telling you to take a seat for two or three years at least,” she said.

So she's stopped waiting for the NYCHA process.

“I don't waste my time anymore,” Santiago said. “I'm always on top of it.”