Building mold-safe home isn't common, but is possible

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Building mold-safe home isn't common, but is possible

By Alan J. Heavens

Seattle Times*

The Philadelphia Inquirer

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PHILADELPHIA — There are better ways to build a house, especially if

you want to keep mold under control, believes.

" Mold is a huge issue for my clients, especially lenders, since they

have 80 percent exposure to the problem through [the] mortgage,

compared with the homeowner's 20 percent equity, " said ,

principal of Environmental Assurance Group, a lending and real-

estate consulting firm, in West Hartford, Conn.

So he agreed when clients suggested he make the year-round house he

planned to build on the site of a lakeside summer cottage in

Chesterfield, N.H., a showcase for mold-resistant construction

techniques and products.

" I said I'd be happy to do it, but that because this was my house,

I'd establish the ground rules, " said.

The result is a " mold-safe model home. " Completed in September, it

was built in conjunction with the Partnership for Advancing

Technology in Housing (PATH), which will monitor how the house

performs over time.

Products and techniques used were chosen based on 's research

and PATH's input. With his approval, PATH brought some manufacturers

into the project.

A lot of builders consider mold-prevention strategies too expensive.

disagrees, though he declined to put a price tag on the 3,000-

square-foot, two-story structure.

" In a house costing a quarter of a million dollars, paperless

drywall represents one-half of 1 percent, or $1,250, " he said.

" I spent $2,500 on a commode and two light fixtures for one of the

bathrooms. Is $1,250 too much to invest in an effort to get mold

coverage put back into homeowners' insurance policies? "

Mold thrives most often in moist conditions, which — combined with a

nutrient source such as soil, dust and products that, like

conventional drywall, contain cellulose or other dead organic

matter — provide the ideal environment.

Indoor-mold problems were aggravated by changes in home construction

wrought by the energy crisis of the 1970s.

Creation of energy-efficient houses in which the air inside is not

regularly exchanged has been linked by the American Lung Association

to a dramatic increase in asthma.

Correcting moisture problems is often the best way to stop mold

growth. Depending on the extent of damage, though, cleanup can run

into tens of thousands of dollars.

After several high-profile lawsuits involving homeowners and

insurance companies, many insurers dropped mold coverage from

standard policies or began requiring special and expensive riders

with higher deductibles.

Building products have been developed that resist mold or create

barriers to the moisture it needs to thrive. Many of them were used

in 's mold-safe house:

Georgia-Pacific's DensArmor Plus paperless wallboard, listed for

microbial resistance by the Greenguard Environmental Institute, was

installed with inorganic glues and tapes (information at www.gp.com).

The wallboard and all the wood in the house were coated with an

antimicrobial spray developed by American Mold Guard

(www.americanmoldguard.com).

The house and roof were wrapped in DuPont's Fiberweb Typar

(www.typar.com), which acts as an air and moisture barrier while

allowing moisture vapor to escape.

It was installed before the exterior siding, which was natural cedar

in keeping with the rural, lakefront view.

The Western red cedar siding was sprayed with a specialized coating

made by Cabot (www.cabotstain.com).

The Typar housewrap was covered with Home Slicker, a ventilating,

self-draining rain screen made by Obdyke Inc.

Home Slicker drains moisture from behind the siding and down the

house, reducing the chances of premature peeling or blistering of

finishes. It allows about three-eighths inch for airflow

(www.benjaminobdyke.com).

CertainTeed provided its Optima insulation for the walls and its

DryRight insulation for the ceiling cavities, both of which are

designed to deny mold a food source. The insulation is covered with

CertainTeed's Membrane, a permeable vapor barrier

(www.certainteed.com).

Builders haven't capitalized on the products, said, " since

[they] are afraid of being first and don't want to be known as

higher-cost producers. "

" They are not going there, they don't want to be cutting-edge, they

want to do it the way they have always done it because that's the

way they always have done it. "

Taking the opposite view is Schaal, director of sales and

marketing for Paparone Homes of New Jersey.

" Builders are concerned about health and litigation issues, so the

construction techniques and materials we use are designed to deter

mold growth, " Schaal said.

" Some builders put dehumidifiers in houses if they know the buyers

will be finishing the basement at some point, " he said. " They coat

the exterior basement walls with waterproofing systems such as

Tuff 'n' Dri, and, in most cases, the residential industry has

shifted from porous concrete block to less porous poured concrete,

to prevent moisture intrusion. "

In townhouse construction, Schaal said, " if the builder uses

Sheetrock between the units instead of block walls, the procedure is

to spray the sheets with a bleach product to kill anything that

could have grown if they were exposed to moisture. "

In existing homes, said Jim Mellon, president of Mellon Certified

Restorations in Yeadon, Pa., " the sources of the mold have to be

located, the areas have to be contained, material removed under

controlled circumstances, then vacuumed, washed and vacuumed again. "

Drywall is porous, and if there's mold it will spread, Mellon said.

Residential mold doesn't get quite the same attention it got a few

years ago, but that doesn't mean the issue has gone away, and

others said.

" If the house smells, it is a problem that must be dealt with, " said

McCann, an associate broker at Prudential Fox & Roach's

Center City Philadelphia office.

" Even if testing doesn't find mold, sellers have to disclose any and

all moisture problems, because if they don't disclose, there's

always the chance of a lawsuit by the buyers, " he said.

Still, McCann said, buyers haven't requested mold testing in any of

the houses he's sold in the last six months to a year.

" If there is no odor involved, but the home inspector notices it,

he'll tell the buyer to have someone check it out. "