Building Science Could Succeed Where Traditional Construction Has Failed in Preventing Home Scourge

by Julie Bonnin

For years, experts in building science—the technologists of construction—have predicted that changes in materials and improper and outdated installation techniques, among other factors, would eventually cause widespread mold problems for homeowners. However, word rarely filtered down from the researchers with doctorates to the guys in the pickups doing the work, said Doug Garrett, president of Central Texas-based Building Performance & Comfort.

But as concerns about mold have grown, builders have turned to building science for answers. Preventing this costly problem likely will require a new approach to house building.

Garrett is a frequent speaker on the topics of moisture management and air quality and a member of the Texas Department of Health’s mold policy committee. Audiences such as the air-conditioning contractors he spoke to recently are hungry for such information.

“I finished speaking at 12:15 and they were still asking questions at 1:30,” he said.

Garrett is among those getting the word out on how to stem the swelling tide of mold problems in homes and other buildings. He and Terry Brennan, a New York-based air-quality expert who also has advised the Texas Department of Health, were among those who spoke at the International Green Building Conference Nov. 13-15, 2002 in Austin.

With Joseph Lstiburek (pronounced stee-brook), a forensic engineer who is one of the world’s foremost experts on energy-efficient construction, Garrett and Brennan are busy advising contractors, architects and others on how to do things right when it comes to designing and constructing buildings.

What’s gone wrong is a combination of factors, they say.

Some building materials in widespread use—paper-covered gypsum board, cellulose ceiling tile, particle board and others—happen to be great food for mold, which can grow wherever moisture accumulates.

Other materials that are in widespread use—fiberglass and cellulose cavity insulation, polyethylene vapor retarders, vinyl wallpaper—make it harder for walls to dry out.

Add tight windows and other features designed to boost energy efficiency, and the lack of air flow creates moisture problems.

Houses have always leaked, Lstiburek said, “but that incidental water didn’t mean much because the building dried so quickly. Now we have to choose different techniques to install windows and doors.”

Another factor, he said, is “cold climate chauvinism” in nationwide building codes: Many good building practices for northern climates have been enforced in places such as Texas, even when they didn’t make sense for the state’s hot and humid climate.

Thousands of homes built in Austin in the 1970s and ’80s, for example, were built with a “vapor barrier” consisting of a sheet of plastic stapled underneath the drywall. Vapor-proofing was designed to keep moisture out of walls in the North, but in the South, it works in reverse.

Water vapor moves from warm to cold and from wet to dry. In the North, that warm, moist air is on the inside of the house, and the vapor barrier serves to keep it from infiltrating the walls. In the South, the warm, wet air is on the outside, trying to move inside, and the vapor barrier effectively traps the moisture within the walls.

The vapor barrier was the perfect place for mold to grow, fed by condensation caused by humidity in the air, Garrett said. The building code requiring the vapor barrier in most parts of Texas was changed last year, he said.

Although some have accused builders of cutting corners and not allowing materials to dry properly as they hurried to meet the housing boom, Garrett said that is less of a contributing factor to problems with mold than the trend toward building complicated structures.

“A lot of the houses having the worst problems are the large custom-built homes,” Garrett said. “The bigger the house, and the more roof angles you put into a house, the more difficult it becomes to do a decent job. When you have lots of complicated details—curved walls, huge walls that are mostly windows—it’s no wonder you have problems.”

All of the discussion about mold has been tracked closely by the Texas Association of Builders, which will propose legislation this year that would put a tighter rein on the state’s building standards.

The group has also been working on a building guide with tips for preventing mold in homes, video training guides for construction workers, and recommendations for going beyond building-code standards when necessary, said Kristi Sutterfield, executive vice president of the organization.

The association also is working on a homeowner responsibility checklist that would be distributed to new homeowners when they close on their home.

“This (mold prevention effort) is the biggest undertaking we’ve taken on,” Sutterfield said. “We’re recognizing that we need to get in and roll our sleeves up and provide homeowner education, builder education and have more input into the government regulation agencies that play a part in all of this.”

Ryland Homes is one of several area home builders that try to use some of the new building techniques.

Ryland builds houses using a program it calls HouseWorks, which uses many of the building science techniques recommended by the nation’s top construction experts to prevent mold.

Key to the program is making sure that the plumbing system, the heating and air-conditioning system, insulation and thermal envelope of the house—the windows, doors and siding—all work together, said Randy Erwin, energy program director for Ryland Homes.

It might sound like common sense to have everything working as a system, but traditionally, construction of many homes is done piecemeal, with separate contractors installing such things as plumbing, heating, air conditioning and roofing with little regard to how they all work together.

Ryland brought in experts who trained subcontractors and superintendents, and developed an inspection team. Sales people also had to be educated about how to sell the new homes.

Although there are added costs to running the program, Erwin said: “It’s not so much the cost that deters (other) builders, it’s that it makes it much more complicated.”

But it’s worth the trouble, Erwin said.

“Our warranty claims have dropped substantially,” he said. “We know we’re having less problems with homes. It’s a lot easier to do it right the first time than to retrofit something.”

Close to 2,000 architects, engineers and other building professionals attended the Green Building Conference in Austin last November. This was the first in a series of such conferences.

Reprinted from the October 19, 2002 Austin American-Statesman. Julie Bonnin is a freelance writer and editor in Austin, Texas.

By Penny Silberhorn, Canadian General Standards Board

In recent years, the face of many professions has changed dramatically. Globalization, altered demographics and the explosion of innovations in information technology have created new opportunities and challenges, and new occupations have arisen to meet the demand. More and more, governments, businesses and an increasingly savvy public are seeking proof of competence through the certification of new and existing professions.

In response to this need for certification, the International Organization for Standardization, Conformity Assessment Subcommittee (ISO/CASCO) initiated the development of ISO/IEC 17024, General requirements for bodies operating certification of persons. This new standard provides a benchmark for certification bodies offering certification of persons in any occupation and facilitates accreditation by national bodies.

Since 1999, the CGSB has supported the development of this standard by sponsoring me as the Canadian delegate to CASCO Working Group (WG) 17, the committee responsible for the standard’s development. The committee comprised members from the Americas, the United Kingdom, Europe and the Pacific Rim. While attending the meetings, I represented the Standards Council of Canada (SCC), Canada’s ISO member body, and brought the Canadian position to the table.

The last meeting of WG 17 was held in June 2002. Publication of the standard is expected by Jan. 2003, after a final round of public consultation. Once completed, many certification bodies will be adopting the standard as a basis of operations, and the SCC will implement the standard by offering accreditation to certification bodies operating certification programs for persons.

This comprehensive standard lays out the general operating requirements for the certification body, including provisions for a management system. It describes conditions for application, examinations, surveillance and recertification. And, it specifies the requisites for independence of training from certification, confidentiality of information, competence of staff and subcontractors, and the need for stakeholder input into certification schemes.

ISO/IEC 17024 is intended as a framework for certification bodies operating a certification program for persons and as the standard against which an accreditation body can accredit the certification body. The standard itself is not enough to certify a person. It is designed to be used in conjunction with a “scheme standard,” which lays out the education, knowledge, skills and experience requirements that a certified person in each occupation would be expected to meet.

As interest in the standard grows, I have had many opportunities to introduce the standard and the concepts for developing a resulting certification program to various groups in the last year. I’ve given presentations to diverse interests, ranging from organizations representing small groups of public sector employees exploring the kind of recognition and status certification would give them, to Treasury Board-sponsored committees considering certification as part of modern comptrollership. Perhaps the largest and most diverse audience attended the presentation at the National Standards System Conference hosted by the SCC last March. This audience comprised public and private standards and certification organization representatives and other related professionals.

There has been great interest in the standard by many professions and occupations and the bodies that currently certify them or will in the near future, and with good reason. By harmonizing the certification process, the standard will provide a basis for international recognition agreements and will promote the global exchange of personnel. It will enable people to expand their career horizons and have their credentials recognized outside of their own country or jurisdiction. A valuable tool indeed!

For more information about CGSB Certification & Qualification Programs or standards, contact the CGSB Sales Centre at: Place du Portage III, 6B1, 11 Laurier Street, Hull, Quebec K1A 1G6 CANADA. Tele: (819) 956-0425 or 800-665-CGSB fax: (819) 956-5644

Reprinted with permission from Calibre, Winter 2002 issue.

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Dr. Steven Spivak commented on the probable effect of ISO/IEC 17024 in the ISO Bulletin, September 2002: “Recently I attended the first ANSI (USA) training seminar on accreditation for personnel certification organizations, using ISO/IEC 17024. Two outcomes were most evident. First, the range and diverse nature of certification organizations attending was impressive. They ran the gamut from certifications representing professional cleaners and restorers, to glass installers and vibration measurement; from speech and hearing specialists, to health professionals in acupunture and oriental medicine. Also present were organizations now providing third party accreditation (prior to ISO/IEC 17024) for certification schemes and organizations. They all represent personnel in vital day-to-day services we often take for granted, or “overlook” in importance. Second, many certifying organizations and service industries already operate at the regional and international level, notwithstanding where their headquarters are located. In ISO and IEC tradition, it is future mutual recognition agreements (MRAs) among certifications for persons, acting to facilitate the seamless, international trade in service, that will become a lasting benefit of ISO/IEC 17024.”

Last year, Rep. John Conyers of Michigan filed the United States Toxic Mold Act (the “Melina Bill”) and picked up 29 co-sponsors. Highlights of the bill include the creation of mandatory disclosures and inspections for rental properties and for-sale housing, licensing for mold assessors and remediators, tax credits for victims, and a federal insurance guaranty program. The bill did not make it out of committee, but was resubmitted in the House of Representatives this session. For the latest updates on the Melina Bill, contact Rep. Conyers’ office at (202) 225-5126.

Increased media coverage of toxic mold contamination issues has resulted in heightened public awareness. Several states have introduced legislation in response to the outcry. California’s landmark Toxic Mold Act of 2001 became a model for many of these bills. A Maryland bill was adopted which established the Task Force on Indoor Air Quality. Bills also passed in Pennsylvania (Senate Resolution 171 and House Resolution 434) and in New Jersey (Senate Resolution 77). In New York the Toxic Mold Protection Act was recently passed, directing the department of health to create an advisory task force to develop exposure limits for indoor environments. Similar bills in Indiana, Michigan and Illinois are pending in committee.

A pending bill in Massachusetts, Senate Bill 2406, is particularly significant because, in addition to inclusion of the major goals of the California Act, it would also render government liable for defective inspections on buildings that become toxic mold-contaminated.

Bills introduced in Texas include HB 329 (passed in the House) and SB 129 (in committee at press time) relate to the licensing and regulation of mold remediators.

A bill in Connecticut, which would have addressed mold in schools, was defeated last year and Arizona SB 1432 would have created a study group to consider the effects of both commercial and residential indoor mold contamination failed to pass this session.

In Florida the commissioner of insurance held forums to address public and industry concerns about the increase of mold claims. New legislation has since been introduced including HB 1659 to deal with licensing issues and SB 2746 to set up a registration system for all mold professionals.

Strong lobbying in all states by the insurance industry to exclude mold coverage from standard homeowner policies continues. In Texas, hit with several large judgements in 2001, several major insurers left the state after failing to achieve protection from mold claims.

Reprinted with permission, from www.healthy-kids.info

On March 18, 1937, in New London, Texas, a gas explosion killed nearly three hundred students, teachers and visitors while in the supposed safe haven of a public school.

An official inquiry into the disaster revealed a litany of false economies, expediency and negligence in the design, installation and maintenance of the heating system, weakness in provisions for ventilation, and totally inadequate venting … in the richest school district in the nation.

Surprisingly, no one was ever held responsible. Instead, the New London Disaster was attributed to “the collective faults of average individuals, ignorant or indifferent to the need for precautionary measures, where they cannot, in their lack of knowledge, visualize a danger or a hazard.”

On March 25, 1937, a nine-year-old survivor addressed the state legislators, urging them to make more protective laws. “Our daddies and mothers as well as the teachers want to know that when we leave our homes in the morning to go to school we will come home safely when our lessons are over.”

Legislation was finally passed to add an odorant to natural gas. Other expert recommendations included “technically trained administrators for modern school systems,” “more rigid inspections and more widespread public education…,” and “a comprehensive, rational safety code.”

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Today, 66 years later, we are still waiting to see schools follow those recommendations. Millions of children go to schools, old and new, that have inadequate ventilation systems and extensive safety code violations. These children are victims of the same false economies and jurisdictional evasions that failed to make safety a priority and that led to the loss of so many young lives in New London, Texas.

[Every few years, however, we hear of parents, teachers and school nurses who organize to clean up their moldy school, despite the opposition of school officials.

[Paul Ruther's news story below illustrates the nature and magnitude of those obstacles, and the incredible persistence it took for parents and teachers to accomplish reforms. -Ed.]