Mold buster

DRESSED IN JEANS and a black polo on a mild summer day in Monbulk, Australia, Tim Law carried his blue tool bag past rose bushes and rolled-up strips of carpet on the front lawn of a single-­level house. He walked inside and deposited his bag full of moisture-testing devices, a tape measure, and a flashlight in a corner of the dining room where the high-end wool carpet once was.

“There used to be 10 dehumidifiers in here,” homeowner Faye Ridley said over the roar of five machines still running, their drainage hoses snaking through window screens. Weeks earlier, a rainstorm left several inches of water and silt throughout most of the home she and her husband built 54 years ago.

Law took out a device with a thick metal antenna. He stooped and pressed it to remaining carpet in the living room to take multiple readings of the floor’s moisture level. He used a different electronic device to read the moisture in the walls. Some of the drywall was still damp. That could contribute to mold growth in the wall space.

Officials estimate at least half of Australian homes harbor mold. Estimates for the United States are even higher. In both places, the science is the same: Mold thrives in moist, poorly ventilated environments. In Australia, unintended consequences of building codes, weather-related flooding, and a hasty response to the housing crisis create a perfect storm of circumstances that leave millions of people living with mold—and suffering from it.

As an architectural scientist specializing in mold, Law assesses water damage to report to the insurer or restorer. In his spare time, he speaks and organizes forums that address the complex overlap of architecture, microbiology, and health.

“You can go to a doctor, and the doctor may not know very much about environmental mold, nor the effects of mold on your health. You could go to a microbiologist, and they know very little about buildings,” said Law.

Australia’s residential building codes between 2003 and 2019 emphasized energy efficiency but lacked appropriate provisions for condensation management. That enabled the perfect growing conditions for mold. With every new home wrapped in vapor-proof paper to reduce the need for heating and cooling, moisture stayed out. It also stayed in, taking up residence with plant-based building materials like wood and paper-faced plasterboard. They provided what Law calls “mold food.”

A worker tears out portions of a home heavily damaged by mold. Alex Brandon/AP

After the 2009 Black Saturday bush fires, the Australian government required all new residential buildings in fire-prone areas to prevent embers from entering the roof space. Many builders responded by adopting the most cost-effective solution—making the attic airtight instead of venting it. Moist bathrooms and kitchens were then ventilated into that enclosed attic space. Architects, inspectors, and builders could all do their jobs to code yet create the ideal environment for mold.

That left many residents suffering mold exposure. Law calls on building surveyors and certifiers to comply with more than just the letter of the National Construction Code, and he also pushes for changes to the code. He said some builders are unaware of the defects they’re including in their builds, and too many people don’t recognize the effect mold has on their health.

Mold growth can have allergenic, toxicological, pathogenic, and inflammatory effects. Some people are more susceptible than others, and low-income renters are more likely to have mold in their homes and suffer from asthma and respiratory illness. But Australia’s housing vacancy rate is just 1 percent. Renters line up by the dozens to view overpriced rental homes smelling strongly of bleach.

Institutional buildings, too, suffer mold infestations. In late February, administrators moved fourth grade students at Balnarring Primary School in Victoria into the library and gym for class. Teachers had banned pounding on the carpet for drumrolls because of the spores that billowed out. Parents said children complained of breathing troubles, eye irritation, and fatigue.

Dr. Sandeep Gupta was a conventional medical doctor before his house flooded and his wife became ill. Now he practices an alternative approach called integrative general medicine. Gupta says that besides mold-linked respiratory diseases, up to 13 percent of Australians may experience chronic inflammatory response syndrome brought on by biotoxins like mold.

The Ridleys wisely pulled their flooded carpet out as soon as possible, since mold can begin growing within two days. The couple, who are in their 80s, will live in a small bungalow next door while the home where they raised their four children gets renovated.

Law pointed to the book of Leviticus, where the priests isolated molds and burned persistent ones: “I think God in His mercy told the children of Israel how to deal with mold. Four thousand years ago, these people already knew you shouldn’t be living in a moldy building.”

Australians, he said, have some catching up to do.