Wisconsin Builder | Residential Construction | Technology rising to battle spores

Technology rising to battle spores

But victory requires commitment, tools and talent

By Sean Ryan
Daily Reporter Staff

Home builders count on anything from insulation to bathroom fans to prevent mold from sprouting, but these products are only as reliable as the people who install and use them.

"A lot of the stuff I've seen has been out there for years, and it's just being used now," said Ed Carroll, Wisconsin ENERGY STAR Homes program director. "A lot of the things we focus on are really good building practices. Oftentimes, some builders are meticulous about it, but you don't see that across the board."

There are a host of products designed to fight mold growth, including basement sealants, ultraviolet and germicidal lights, various ventilation and air exchange systems, air-filtration systems and an entire line of insulation.

But in general, outside weather barriers and inside moisture controls are the best products contractors can use to prevent mold, Carroll said. However, contractors can only successfully implement these products when they build a home as tight as possible.

"It's really not the insulation product; it's the framing detail," Carroll said. "The tightest homes in (the ENERGY STAR) program don't have expensive insulation. We know that all types of insulation work if it's installed well."

After constructing an air-tight home, contractors must use some sort of weather barrier to block cavities in the exterior walls where water could seep in, especially around windows and doors, he said. These barriers could include waterproof house wraps, felt papers or flashing tape.

"When you are installing a window, how are you detailing it with a sealant?" Carroll asked. "If you are using a type of tape, is it installed in shingle fashion with overlapping layers? This reduces the ability of water to seep in through cracks."

Indoor prevention

After sealing the outside with a tight frame and solid weather barrier, contractors also must use ventilation systems and dehumidifiers to allow moisture to escape the house, Carroll said. There is no golden rule about what system works best, he said, and contractors must decide based on each home's individual circumstances.

"It depends on (the home owner's) lifestyle and how tight the home was built," Carroll said. "It's a house-to-house deal. But you need some kind of mechanical fans and you need some kind of way to control them."

Contractors can provide ventilation with anything from bathroom fans or kitchen hoods to air-to-air exchangers that circulate outside air into the house and expel inside air. Carroll said many contractors are controlling moisture with dehumidistats, which control household humidity the same way a thermostat controls heat.

Residential contractors face growing mold problem

"If the humidity in the air goes above 40 percent, the dehumidistat signals the fans in the house to kick in and lower it," Carroll said. "Those can provide better assurance of ventilation. We don't find the need for air-to-air exchangers in every home, they may overventilate the house."

Even if contractors put proper ventilation into a home, it won't do any good unless they teach the home buyer to use the system properly, said Joe Nagan, technical director for ENERGY STAR and consultant with Kaukauna-based Homebuilding Technology Services.

"The well-educated customer is a good ally to the builder because without them you are just screwed," Nagan said. "Minimal amounts of ventilation will work as long as they run long enough. Until the builder shows the consumer how all these systems work, they can sell them all this stuff but the customer will still beat them up."