Preventing Mold and Mildew Growth In New Homes

Are you building a new home? If so, you've got many important things to think about ... from the design of your new home to mortgage decisions and insurance arrangements. Another important item that should be on your list is health concerns from moisture, mold and mildew growth.

Tighter construction methods?and the materials used to build new homes?can easily contribute to indoor air quality issues and serious moisture problems if builders and homeowners overlook the underlying factors that cause them.

As an example, polyethylene has long been used as a vapor barrier to keep moisture out of homes because it's inexpensive and completely impervious to water. Unfortunately, a house wrapped in polyethylene can also prevent moisture that's already inside the home from escaping. This results in higher humidity levels, which in turn can result in the rapid growth of mildew and mold.

Newer polyamide films installed over insulation material may be a better choice, according to Glenn Singer, managere of building science for CertainTeed's Insulation Group. CertainTeed's MemBrain vapor retarder, for example, is designed to allow excess moisture to evaporate and exit the home through tiny pores that change size as relative humidity changes.

Construction products used in bathrooms are another area for discussion with your builder. Recent changes to the International Residential Code (IRC) no longer recognize green board?a commonly used, paper faced drywall product?as a suitable tile-backing material in wet areas like tub and shower surrounds. Instead, an approved, cement-based backer board like Durock? from USG Corporation should be used.

Durock panels are composed of aggregated portland cement sandwiched between layers of reinforcing glass-fiber mesh, providing a much greater resistance to moisture and a lower risk of mold growth. Green board products are still suitable for use in bathroom, laundry room and basement walls.

Air treatment systems are another important consideration for consumers planning to build a new home, and well worth discussing with your builder. Whole home systems, like those available from Aprilaire, might include an air cleaner, a humidifier, and a dehumidifier?all of which are installed in conjunction with your new home's heating and cooling systems.

A purpose-built dehumidifier is more effective at controlling indoor humidity than an air conditioner, and whole-home units are typically more efficient to operate than portable models. Humidifier units help provide proper humidity balance throughout the year, but are particularly helpful during the dry winter months.

Make a checklist of your concerns and ask your builder about how your new home will be constructed, what construction products will be used, and what steps they'll be taking to mitigate the likelihood of a moisture retention problem and indoor air quality issues. Indoor air pollution, humidity buildup, mold and mildew are all problems that are avoidable, and they're all things you definitely don?t want in your brand new home.

The Home Improvement News and Information Center provides information and resources for home construction, remodeling and home energy management. For more information about home building materials, point your web browser to http://www.HomeImprovementTime.com/consumer/search.asp?search=remodel&mode=search.