Show houses are a great way for builders and manufacturers to showcase the latest and greatest in products, materials, construction techniques, and design. This month, the first-ever show house for mold prevention opened its doors in Chesterfield, N.H.
The house was developed by Partnership for Advancing Technology in Housing (PATH) Partners, a group of manufacturers, builders, organizations, and individuals that support the work of PATH, a research group under the U.S. Department of Housing and Urban Development that identifies and tests innovative processes, materials, and technology for the housing industry. The 3,000-square-foot, two-story lakefront home will serve as a living laboratory to study a new mold-prevention protocol that includes the use of mold-resistant building materials, such as paperless drywall and non-organic insulation, and an inspection process that runs from design through occupancy.
The first event at the Mold-Safe Model Home will be a meeting on Sept. 14 of the New Hampshire chapter of the American Institute of Architects.
Like the National Homebuilder Mainstream GreenHome in Raleigh, N.C., a demonstration home for green building on which PATH is an advisor, the Mold-Safe Model Home is an actual residence to be occupied by a family. Both houses will have monitoring systems to permit on-going study of the performance of the systems and materials.
The house is owned by Charlie Perry, president of Environmental Assurance Group in West Hartford, Conn., an environmental insurance agency that covers such issues as underground storage tanks, asbestos, lead paint, and mold.
"Mold is not a problem you want to deal with and fix later on," Perry says. "Try as you may, once you get it there, you'll probably be very unlikely to get rid of it. ... The goal [with the mold-safe model home] is to be able to build a home that is mold- and moisture-free."
If that can be done, insurance companies will be willing to offer mold coverage on the property and lenders might offer a slightly better financing rate, Perry says. "If that is the case and we can make it cost-neutral to the homeowner, that would be a wonderful thing," he adds.
The two primary issues the house addresses are keeping water away from the house and removing mold's potential food sources. On the first objective, the design of the house called for two layers of drains, one at the footings and another halfway up the foundation wall. Additionally, it was built with 2 1/2-foot overhangs, as opposed to the standard of 8 to 12 inches. With the larger overhangs, water comes off the roof much further away from the foundation.
Plus, the house and roof were wrapped with Fiberweb Typar. On the roof, the Typar was topped with Grace Ice & Water Shield. "Then on top of that, we had a roof made of slate," Perry says. "Snow and ice literally rolls off."
To make the house as natural as possible in keeping with its rural, lakefront setting, Perry selected natural cedar siding. Because water permeates wood, the housewrap was covered with Benjamin Obdyke's Home Slicker, a ventilating, self-draining rain screen. It allows for about 3/8 of an inch of airflow and allows water to easily drain down the side of the house. The cedar siding is treated with a specialized coating by Cabot.
Inside, the process focuses on eliminating mold's food source by using Georgia-Pacific's paperless wall board, DensArmor Plus, and CertainTeed's Optima insulation in the walls and its DryRight insulation in the ceiling cavities. The drywall was installed with inorganic glues and tapes. Plus, the insulation is covered with CertainTeed's MemBrain, a permeable vapor barrier that allows for air exchange in cold, dry weather, but prevents humid air exchange on hot, muggy days, Perry says.
In addition to the drywall, all the wooden structures of the house were coated in a permanent anti-microbial spray developed by American Mold Guard.
A major issue for building a mold-free house, Perry says, is convincing builders to use a different process or material than the ones they've used for years - or one that costs a little more. "The difference in cost in my house to use paperless drywall was probably less than a faucet and two lights over the vanity in the bathroom," he says. "People will say it's double the cost of regular drywall, but the overall cost of drywall in a house is half a percent of the total cost. In a $250,000 house, that's $1,250. I spent $3,000 on a vanity top. Would you rather have a mold-free house or a different vanity top? It's a silly argument."
For more information on the Mold-Safe Model Home, visit PATH at www.pathnet.org/sp.asp?id=24139
For information on PATH Partners, visit www.pathnet.org/sp.asp?id=1315
Western Red Cedar Lumber Association
Learn more about markets featured in this article: Hartford, CT.