Residential contractors face growing mold problem
But industry officials are seeking solutions

By Sean Ryan
Daily Reporter Staff

Mold grows freely in the attic following a residential construction job. All mold needs
to survive is the right temperature, a food source and a little moisture.

"Behold, if the plague be in the walls of the house with hollow streaks, greenish or
reddish, and the appearance thereof be lower than the wall; then the priest shall go
out of the house to the door of the house, and shut up the house seven days. And the
priest shall come again the seventh day...if the plague be spread in the walls of the
house; then the priest shall command that they take out the stones in which the plague
is, and cast them into an unclean place without the city."
--Leviticus 14:37-40

If the Book of Leviticus is any indication, mold could have been growing in houses since
the Old Testament was written, making it older than the contracting industry, older than
Wisconsin and about the same age as dirt.

So why has it taken so long to become a pressing issue in the home-building industry?

"Homeowners have put up with a lot of stuff for years, and now they're becoming more
aware of it," said Mark Chamberlain, environmental health specialist with the Wisconsin
Department of Health and Family Services' Division of Public Health. "It is something that
people are paying more attention to. People are more aware of it since there have been
a few high-profile cases."

The problem of domestic mold didn't change as the issue became more high profile,
Chamberlain said, and the same types of mold are growing in houses the same way they
always have. The difference is homeowners today know the symptoms of a moldy house
and are quicker to take action if they discover it.

"It's more awareness, and it's more education," he said. "I think you're just going to have
more informed customers who are going to have their eyes out and keep contractors on
their toes because contractors aren't keeping up with the times."

Three easy ingredients

The bad news about mold is the spores that spawn it are everywhere, Chamberlain said.

"You're not going to get away from it," he said, "You can't make sterile houses. You can't
make sterile building materials."

The good news is spores need three things in order to grow mold: a temperature between
40 degrees and 100 degrees Fahrenheit, a food source and moisture, said David Crump,
staff council for the National Association of Home Builders. Since all homes provide the
correct temperature, and mold can feed on wood products, insulation, ceiling tile or fabric,
the only factor a contractor can control is moisture.

"If you add moisture to this mix, mold can develop in 24 to 48 hours," Crump said.

James Lyons, director of energy and environmental programs for the NAHB Research Center
in Virginia, has been inspecting homes for mold in order to gather clues that could lead to
preventative measures. He said there isn't one predominant cause of moisture because it
can come from roof leaks, condensation, wet basements or residents' home maintenance.

"Attention to moisture problems, to the extent that you can react to it in a timely manner,
will control your ability to prevent some widespread problems," Lyons said. "The answer at
that point is to control the humidity inside through dehumidifiers and bringing in outside air."

Bringing in outside air is increasingly difficult because energy-efficiency standards for homes
are forcing contractors to build tighter houses with less ventilation, said Mary Anne Moore
-Church, Wisconsin Builders Association president and co-owner of Sweetwood Builders Inc.,
Appleton. Contractors must install more ventilation systems and tell their clients to use them
so moisture can escape the home.

"In solving one problem, we've created another," Moore-Church said. "As we try to make the
houses tighter to prevent heat loss that's what's going to happen. We're caulking every hole."

Bill Hart, project manager with Windsor Homes in Madison, said he installs mechanical air
exchangers to drive out moisture from residents' breathing, cooking, plants or showers.

"You need to put an air exchanger in new houses because they're too tight because of all the
new building codes," Hart said. "When we build a new home, we put an air exchanger in it.
We haven't had any complaints (about mold)."

Keeping dry

There are a number of good building practices that can protect a house from mold growth.
Even Leviticus lists a number of protective procedures, including sacrificing a bird and
"cleansing" the house with its blood, but these don't seem practical in the modern world
of home building.

Chamberlain said many contractors have problems because they don't protect their building
materials from the weather on the work site. Most manufacturers spray their materials with
chemicals that prevent mold growth, but these chemicals will only protect damp material for
a limited amount of time.

"If you have construction materials out in the open elements, you are just inviting problems,"
Chamberlain said. "You are inviting problems if you are not getting the moisture out of the
building as soon as possible. Once you start putting sheet rock or plaster into a house, you
should have it sealed up."

Other reoccurring mistakes include contractors leaving parts of the roof unprotected or not
draining water from the basement excavation before installing the foundation, he said.

"We tend to see certain contractors exacerbate the mold problem by doing things like leaving
the roof unprotected," Chamberlain said. "Contractors who have water in unpoured basements
and are not pumping it out and just leave the water there when they're building are just inviting
problems."

Even the most careful home builder is not immune to mold trouble, Crump said, because
mold sometimes grows because homeowners don't properly maintain their houses. Residents
who don't clean up spills or don't run the bathroom fan during showers can cause moisture
problems in the most well-constructed house.

"They are the people living in their home, and they have a responsibility to maintain it," he said.
"Mold is not necessarily, or even usually, a construction issue. It's more frequently a
housekeeping issue."

Moore-Church said builders could minimize the occurrence of mold caused by residents by
discussing proper home maintenance with them. She said builders should stress the importance
of ventilating new homes in the first two years, when plaster and concrete are still new and moist.

"For the first one to two years, depending on the climate and the time of completion, you may
need to take more precautions," Moore-Church said. "Most builders try to talk to owners about
fans and things. Most people are pretty intelligent and understand the process. Because there
are many things that can happen to a house after a close, (contractors) have to protect
themselves from liability."

Under the gavel

As more and more homeowners across the country sue their contractors for domestic mold,
the threat of litigation is becoming a looming issue, Crump said. Damages awarded and the
plaintiffs' chances for success vary greatly.

The high-water mark, Crump said, was $32 million in damages against construction insurer
Farmers Insurance Group for insufficiently cleaning mold out of an infected home in Dripping
Springs, Texas.

"There are cases in many states, particularly states that have high humidity," Crump said.
"It increases costs because insurance gets more expensive. Insurance companies are
raising their prices and limiting their coverage against mold claims."

Although the cases are springing up more and more, Moore-Church said she hasn't heard
about any in Wisconsin.

Crump said recent mold cases against residential contractors are starting to include
personal-injury claims along with the usual property-damage claims, with prominent cases
filed by legal activist Erin Brockovich and former Tonight Show co-host Ed McMahon.
These cases are all still pending since no research has been able to directly prove that
mold causes health problems.

"The personal-injury attorney has seized on mold as another type of liability recovery,"
Crump said. "Those are not based on hard science. They're based on speculation. The
(Centers for Disease Control) has said there is no data that supports this at this time."

Even without scientific evidence or legal precedent to determine if mold causes health
problems, homeowners are pushing cases hoping for a favorable jury ruling, Crump said.
Until the CDC finishes its studies on the issue, it is up to the courts "to teach when it is
clean, and when it is unclean," as Leviticus put it.

Technology rising to battle spores

"They continue to be filed and asserted, but the hard evidence as to whether mold was
the cause is lacking," Crump said. "It's all up to judge and jury."

However hot and prominent mold has been lately, Crump said it hasn't caused any major
shifts within the home-building industry.

"I don't think it has been driving the home sales down," he said. "We are in a rapid period
of growth in the new-home building industry. I don't know that we have seen anything that
has caused anything, but obviously it is a concern."

Return to the Mold Articles Page