Mold's mission:

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Posted on Sat, Apr. 29, 2006

Mold's mission: To eat, decompose your house

Check for places where moisture accumulates

http://www.charlotte.com/mld/observer/living/home/14458006.htm

MARY BETH BRECKENRIDGE

Knight Ridder

AKRON, Ohio - What you don't see can hurt you.

Mold in buildings can compromise structures and make people sick.

Sometimes that mold lurks in hidden places -- behind the walls, in

the air conditioning system, on the underside of Grandma's old chest

of drawers.

Yet people often ignore those sources, simply because they're not

visible, said May, a mold-investigation specialist and

author of " The Mold Survival Guide " (s Hopkins University Press,

$18.95).

" People react most strongly to what they can see, " said May, who

owns May Indoor Air Investigations in Cambridge, Mass. So the slimy

gunk in the shower or the black stuff in the attic may worry them,

when those probably aren't nearly as threatening as what's under the

basement carpet or behind the paneling.

Before you panic and start tearing out drywall, however, you should

know that serious mold infestations aren't rampant.

In fact, most houses don't have a significant mold problem, said

Sill, owner of Cierra Environmental, an Ohio company that

specializes in mold inspection, testing and remediation.

In those that do, there's some sort of underlying cause, such as

improper ventilation, a leak in a water pipe or a bathtub overflow,

Sill said. " The mold follows the water, " he said, " and the water

doesn't just appear in the house. "

Even if your house does have mold, the problem may not be

significant if no one in the house is sensitive to it, said Thad

Godish, a professor of natural resources and environmental

management at Ball State University, who has researched mold

contamination of buildings. But for people who are sensitive to it,

mold can trigger asthma, chronic coughs and more serious respiratory

ailments.

Mold is in the air all the time, Sill and May said, so it's

impossible to achieve a level of sterility that would make a house

mold-free. Nevertheless, May believes mold shouldn't be growing

unchecked in any home.

So what is mold, anyway?

Mold is fungus -- actually, any of many types of fungi. Mold plays a

useful role in nature, because it secretes enzymes that break down

matter.

Mold becomes a problem, however, when it starts feeding on things we

don't want it to, such as the wood frames of our houses or the paper

that covers drywall. Mold can weaken and ultimately destroy parts of

a house. It can send spores and other particles into the air we

breathe.

" Mold is out there doing its job, " Godish said. " It's trying to eat

your house down. If you give it a chance, it will. "

The most common types of fungi in a home -- what we typically refer

to as mold or mildew -- belong to the genera " Cladosporium,

Penicillium, Aspergillus, Alternaria, Stachybotrys and Chaetomium. "

Different types of mold feed on different substances, such as wood,

cellulose, dust and soap scum. All need food and water to grow.

How big a problem these molds pose depends partly on how much is

present. A trace of mold around the edges of windows isn't likely to

release enough spores to cause health problems, Sill said, while a

moldy section of basement wall could be a breeding ground of misery.

One of the most common hidden sources of mold in modern buildings is

the air-conditioning system, May said. In summer, water pools in the

unit and provides the perfect breeding ground for mold. In winter,

when the mold is dry, particles are easily picked up and blown

through the air.

Thriving in darkness

Basements and crawl spaces are other places where mold tends to

grow. The relative humidity typically is higher there than in the

rest of the house, and Sill said the darkness allows mold to grow

faster.Mold is also common in attics and bathrooms -- particularly

bathrooms that don't have a fan or that stay steamy for a long time,

Sill said. Houses that are left unheated can experience mold growth,

too, because moisture from the air condenses on the cold walls.

Mold-fighting Tips

Here are some answers to questions about mold, gathered from mold

authorities Thad Godish, May and Sill:

Q. How can I prevent mold? The best prevention is careful home

maintenance. Never ignore a leak, because it takes only days for

mold to grow. Fix openings in the house's outer shell where water

can seep in, and make sure your attic is properly ventilated.

In the bathroom, open a window or use a ventilating fan when you

take showers. Make sure the fan is vented to the outside of the

house, not into the attic. If you don't have a window or ventilating

fan, set a small oscillating fan on the vanity to help dry the room.

You might even dry your towels outside the bathroom if the moisture

is significant.

In the basement, use a dehumidifier if the relative humidity there

is higher than 50 percent, and keep the temperature at 60 degrees or

above. Carpet in basements frequently harbors mold, since moisture

condenses on the cold floor. Consider a hard floor with an area rug

instead.

Even something as simple as regular cleaning helps prevent mold

growth, since mold grows on dust, dirt and soap residue.

Q. How do I know I have a mold problem? Mold can be hard to detect,

because it often hides where we can't see it.

A moldy smell is a tip-off, although you can have mold without the

odor. Unexplained respiratory symptoms are another clue,

particularly if they go away when the affected person leaves the

house for an extended period.

Suspect mold in any house that's had a leak or flood, particularly

if the problem wasn't remedied and the area dried out promptly.

An older home is more likely than a newer one to have mold, simply

because the probability of leaks and other problems increases with

age, Godish said.

Q. What should I do if I suspect I have a mold problem? Have an

inspection done and the air in your house tested to find out whether

a problem exists. Expect to pay $100 to $250 for an inspection, Sill

said.

An inspection may not be necessary if the source of the mold is

obvious, he said.

If the inspection shows you do have a problem, multiple samples will

often be required to determine the source. Those samples need to be

analyzed by a laboratory, so they aren't cheap -- about $75 each,

Sill said.

Sill suggested getting two or three estimates from mold remediation

specialists. Avoid anyone who offers ozone-type products or promises

to get rid of all the mold in the house, he said.

Q. Can I remove the mold myself? Maybe, if you have only a small

amount of visible mold -- less than 10 square feet -- and you know

what you're doing, May said.

Nonporous surfaces can be cleaned with a solution of chlorine bleach

and water. But don't just spray the bleach solution on, Sill said;

apply it with a towel, so you don't leave excess moisture on the

surface to start the whole mold-growth process again. Wear proper

gear to protect your skin and eyes.

After you've removed the mold, you can prevent a recurrence by

applying special bathroom paint formulated to prevent mildew growth.

Porous surfaces, such as insulation and drywall, need to be replaced.