Prevention Helps Minimize Risk of Indoor Mold

 

Mold has recently turned into the newest four-letter word in the minds of homeowners. Dreaded by insurance companies, realtors, homeowners, and builders, the question everyone is asking is how to prevent mold from growing in a home. Although experts don’t always agree on the long-term effects of mold on humans, almost all agree that good building standards and proper home maintenance can prevent or inhibit its growth indoors.

One of the factors affecting the growth of indoor mold is related to modern changes in building materials and techniques. Much more than simply bricks and sticks, every home is actually a complex system made up of interacting components, materials, and subsystems. Change one, and others may change in unanticipated ways. In some of today's houses, this has resulted in conditions that favor the growth of mold.

Although there are many theories on why we seem to hear so many reports of mold in modern houses, experts in the construction industry believe there are several factors that contribute to these increased reports. Perhaps most important, houses are now builder “tighter” than in years past. Tighter homes tend to dry more slowly, so they may accumulate higher amounts of moisture than in the past.

Increased levels of insulation are also believed to play a role in increased indoor mold. The under- or non-insulated homes of previous generations allowed for heat to flow through walls and ceilings, enabling building materials to dry out before mold could begin growing. In today’s highly insulated homes, even a minor leak can sometimes lead to persistent moisture, allowing mold to set in.

Experts also believe that today’s choice of building materials often allow for the increased development of mold. In general, today’s homes use less brick, stone, and concrete – materials mold can’t process. When wood is used, juvenile lumber containing a higher proportion of mold-prone sapwood is often selected. Sawn lumber has been replaced by particleboard and traditional plaster has given way to paper-faced gypsum – materials that water can easily penetrate and turn into fodder for mold. Add to this list items like air conditioners which reduce humidification, exhaust-only ventilation systems, leaky air ducts, and vinyl wallpaper, and a home quickly becomes a mold-friendly environment.

Before hitting the panic button, however, experts are also pointing to several things builders can do to minimize the growth of mold. A good builder knows that mold prevention begins with the basic principle of keeping the home dry. By paying attention to the details of a construction plan and understanding the interrelated system the plan creates, a good builder will begin with dry materials, design a home to remain dry, and plan for ways for the house to dry out should it get wet. Some of these techniques are as simple as ensuring that drains work properly and that pipes are fitted together well to avoid leaks. Other techniques require more skill, addressing water shed patterns on exterior surfaces, air and vapor barriers, insulation details, and HVAC system design.

Inhibiting the growth of mold begins with the building envelope and foundation. Experienced builders know there is virtually no surface in the home that is waterproof. Windows, doors, walls, and joints leak. Because of this, water protection is not about waterproofing, it’s about drainage. Planning for proper ventilation within the infrastructure of the home increases the chances of the inevitable damp surface drying out before mold sets in. In addition to proper ventilation, gutters, downspouts, and good foundation drainage also protects the foundation from water and mold.

Inside the home, bathrooms are notorious for mold development. Contrary to popular belief, “moisture-resistant” drywall is not always mold-resistant. Some experts now recommend that tile be laid on specially-designed backer board instead. Some even suggest foregoing tile altogether and opting for a nonporous sheet material like solid surfacing. Fewer cracks and gaps mean better odds of keeping the system dry. In addition, good homebuilders will include a high-quality ventilation fan, even if the bathroom has windows. These fans are vented to the outside, not the attic, to avoid the introduction of humid air into interior spaces.

Although it’s an obvious fix, builders are paying closer attention to plumbing. Pans under water heaters and washing machines provide additional safeguards while easy access to drains under sinks allow for quick detection and repair of leaks.

For homeowners, the best defense against mold is a good offense. Treat even the smallest amount of water intrusion like a major leak. The problem only gets worse the longer it is allowed to continue. And if water does penetrate building materials, the key is getting them dry as quickly as possible. Stopping the water flow at its source, removing wet materials such as carpets and pads, and even placing fans in front of damp drywall can stop mold before it begins.

Experts recommend rethinking common cleaning routines as a means of removing mold. People often think they should use bleach on mold, but industry standards now recommend against it. According to these experts, bleach does not kill mold spores, and the bleach itself is an irritant and can be harmful to those within the home. Experts remind us that mold is an allergen whether it's dead or alive. If the surfaces and materials within a home remain clean and dry, mold will not grow. If surfaces are continually wet, mold will grow back even if you wash with bleach. Instead, new recommendations suggest using a general-purpose cleaning detergent to clean, making sure that surfaces are left dry.

Choose a builder who will treat your new custom home as the complex system it is, paying careful attention to items such as ventilation and water drainage. The result will be a more efficient, healthier living environment for you and your family.

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