FAIRBANKS - The weatherproofing of homes in Fairbanks is leading to a different problem - mold - and a lack of disclosure may leave renters susceptible to health risks.
Building experts in the cold-weather city tell the Fairbanks Daily News-Miner that more residents are facing mold problems because they seal their homes without ventilating properly.
Homes in cold climates are susceptible to mold because of the extreme temperature differential between inside and outside. Mold needs water to grow and moisture develops in homes when water vapor inside hits cold surfaces such as windows and outdoor walls and condenses into liquid.
"People are still too often addressing one side of the energy equation ... making walls thicker, increasing R-values and tightening homes. They are not addressing ventilation," said Steve Shuttleworth, building official for the city of Fairbanks.
Bill Reynolds, who has inspected more than a thousand homes through his business, said renters often do not know about mold when they move in. He sees mold residue that has been painted over without resolving the cause.
A big or exposed mold colony can cause structural damage and health problems, such as hay fever or respiratory difficulty.
The problem dates back several decades, said Mike Musick, a retired energy auditor.
Many homes built before the 1970s had single-pane windows and no vapor barrier. In winter, thick layers of ice would form on windows.
"In the '70s, when energy conservation became a real serious issue, we started tightening our houses," he said.
High fuel prices and the availability of home-energy rebates have caused a rush to retrofit homes. The state has provided $360 million for weatherization and home-energy efficiency since 2008, allowing homeowners to get an energy audit, add insulation and seal natural leaks. Not enough of those dollars have gone toward ventilation, said Rich Seifert, energy and housing expert at the University of Alaska Fairbanks.
"The state did a wonderful thing to put $360 million on the table," he said. "But the justification for what changes are made to improve the house are all based on payback. The things you need to do that are the most crucial to maintaining health offer the least payback, like changing the windows and putting in adequate ventilation."
People produce moisture when they cook, shower and breathe. Mechanical ventilating provides an escape for moisture, even if it's just a bathroom and range hood fan, Musick said.
"If you remove moisture and pollution where it's most generated, like the bathroom or over the range, immediately, then it doesn't have a chance to get in and have a deleterious impact on indoor air quality," he said.
Renters, Seifert said, may not know they're moving into a home with problems.
"Lower-income renters are subjected to living in the worst housing with the worst oversight," Seifert said. "So you have people who can least afford health problems being subjected to poor living conditions and all the problems mold can lead to."
There is no mold policy for rental properties, only a line in the Alaska landlord-tenant act requiring landlords to keep all areas "in a fit and habitable ... clean and safe condition" and maintain any existing ventilation system. The law does not require an inspection but says if a tenant requests it, "one should be prepared."
"The landlord is not required to make a mold disclosure, and a lot of these people don't have the money to move," Reynolds said.