Building more durable homes

[Guest guest]

http://www.startribune.com/

Saturday, November 18, 2000

Building more durable homes

Jim Buchta / Star Tribune

The housing industry is wrestling with a litany of problems, including

incorrect use of materials, untrained workers, a lack of job site

supervision, overworked inspectors and buildings that are becoming too

complex.

That's the view of Steve Easley, keynote speaker at a conference last week

in Madison, Wis., where more than 200 building scientists, product

manufacturers, researchers, policymakers and builders discussed how to build

more durable and disaster-resistant houses.

The second annual Durability and Disaster Mitigation in Wood-Frame Housing

Conference was cosponsored by the Forest Products Society and the

Partnership for Advancing Technology in Housing (PATH).

Established by the Clinton administration in 1998, PATH is a federal program

that helps develop public-private partnerships and facilitates the

development of technologies that improve the quality, affordability,

durability, energy efficiency and environmental performance of houses in the

United States.

Easley is an internationally recognized building consultant and a former

professor of building construction and contracting at Purdue University. He

also is co-host of a Discovery Channel program, " Your New House. "

Moisture problems

Builders and subcontractors need to do a better job of understanding simple

building physics, Easley said, notably how moisture moves throughout a

building. He estimated about 90 percent of all major building failures are

caused by leaks that let moisture get to places where it shouldn't.

Such leaks often are caused by poor design, he said.

" The architectural community has to be more aware of these issues, " he said.

For example, more houses have short roof overhangs that don't keep rainwater

and other elements away from the house.

Builders also must employ good water management techniques and should stop

thinking of exteriors such as siding and stucco as watertight weather

barriers. " Most houses have thousands of feet of cracks, " he said. " We

should design buildings as if siding will never be put on. "

Water also gets in through poorly executed flashing details -- usually metal

strips used to weatherproof joints where exterior wall and roof surfaces

meet at an angle -- around chimneys, windows and doors, he said.

" The industry is weak on this, " he said, estimating that 90 percent of all

window leaks are the result of bad installation or damage caused before the

windows arrive on the job site.

Easley also is critical of builders and homeowners who rely too heavily on

caulk to stop leaks. " We can't rely on caulks and sealants to keep water

out, " he said. " It should only be a tertiary measure of control, not a

principal measure. "

And he said he's frustrated by how often he sees building materials exposed

to the elements on job sites. " I see lots of framing packages show up on job

sites with mold on them ... builders have to figure out better ways to

transport and store lumber. "

Unsuitable building sites are another problem, he said. Too many houses are

built where they shouldn't be constructed -- near wetlands, on cliffs and on

unstable ground.

The solution to these problems? More research would help, Easley said.

Research deficit

Less than 2 percent of the $250 billion spent on residential construction

each year is used for research and development of techniques and materials,

he said.

More money needs to be spent to understand the house as a system, he said.

The durability of houses, particularly those built during the past two

decades, has become a growing issue as homeowners across the country

discover costly and annoying durability problems such as rotting walls and

damaged siding, he said.

For years, some builders have denied that the housing industry faces such

problems, but Pat Huelman, a researcher with the University of Minnesota's

Cold Climate Housing Center, said holding the conference was acknowledgment

of the issue. He described the event as a constructive forum that brought

together once-disparate industry groups to discuss the issue.

Durability problems often are caused by warm moist air that gets trapped in

wall cavities and by water that leaks from the outside into the wall system.

Building scientists are learning that many modern materials don't tolerate

frequent moisture and can harbor mold and eventually rot, which can have

grave consequences for homeowners.

Moisture problems can cost thousands of dollars to fix and exposure to molds

can have devastating health effects, said McGregor Pearce of Mold Sampling

and Diagnostic Service of St. , and Daggett, a toxicologist with

the Wisconsin Bureau of Environmental Health.

Some people have blamed moisture problems on Minnesota's stringent energy

code, which sets standards for the way houses should be built by focusing on

the energy efficiency of the house.

Builders increase energy efficiency by tightening the house and reducing air

leaks. Older homes usually had many air leaks, which gave walls a chance to

dry out once water got inside. Many older houses usually were built with

solid wood products that are more tolerant of moisture exposure than many of

the wood composite materials used today.

Experts at the conference said durability problems are complex and can't be

attributed solely to national energy codes.

Role of building codes

Steve Hernick, one of three Minnesota building officials who attended the

conference, said it is clear that problems he's seeing in Minnesota are

widespread and can't be blamed exclusively on the state's new energy code,

considered one of the most stringent in the nation.

" The issues I see in Minnesota are not unique, they're national, " Hernick

said. " It's the same set of issues: durability, indoor air quality and

enforceability of the building code. They're the same concerns people are

associating with the energy code, but they're really problems of residential

construction right now. "

During the three-day conference there wasn't much consensus about how to

solve durability problems, but there was broad agreement that the problem is

complex, and approaching the house as a system works best. That theory

considers how all of a home's components -- including all of the aesthetic,

mechanical and structural elements -- work together.

Several goals were set when PATH was initiated, , including increasing

energy efficiency and reducing the environmental impact of building new

houses. The program also seeks to increase housing durability by 50 percent.

" I think durability is a significant problem, " said Burdock,

executive director of PATH. " Houses are built better than before, but I have

concerns about the way the whole house is coming together, the way they're

constructed. It's a science that there needs to be serious attention and

focus on. "

PATH has a couple of cousins under the federal umbrella, including the

Department of Energy's Building America program and the Environmental

Protection Agency's Energy Star program. Both of the programs focus on

increasing energy efficiency and improving construction processes, which

have a net result of greater durability, said Armin Rudd, of the Building

Science Consortium in New York. There are Minnesota builders who participate

in both the Energy Star and Building America programs.

Burdock said much of PATH's $10 million budget for 2000 is dedicated to

facilitating the development of new technologies that increase durability

and disaster resistance.

She said while it's laudable that homeownership rates have hit record

levels -- nearly 70 percent -- many home buyers are people who might not be

able to afford to maintain them. That's why it's so important to build

durable, energy-efficient houses that cost less to maintain and to heat and

cool, she said.

" We're looking at keeping people in their homes, " she said.

PATH works with more than 100 product manufacturers, including Andersen

Windows Corp. of Bayport, to develop technologies to improve durability and

disaster resistance.

, an Andersen Windows materials engineer, said his company is

working with PATH and the American Plywood Association to build a

demonstration house at the Forest Products Lab in Madison to showcase PATH

products and techniques.

" We build a durable product and therefore the durability of a home is

important to us, " said.

Industry fragmentation

Karl Kardel, a window specialist from Piedmont, Calif., said the

homebuilding industry is fragmented and grappling for solutions much like

the auto industry was during the 1970s when it was trying to improve the

quality and fuel efficiency of cars. " We have industries that don't know how

long their products perform in the field, " he said.

Several building scientists at the conference expressed concern that there

are no clear expectations about how long a house and its components should

last, even though many believe some houses won't outlive their 30-year

mortgages.

That's why one of Burdock's challenges this year will be to establish a way

to measure the program's progress toward its durability goal.

But gauging progress will be difficult because there's little consensus

about what durability is, said Quarles, wood durability adviser with

the Forest Products Laboratory at the University of California in Richmond.

He said even without measurable results, the PATH program is a step in the

right direction because it brings the durability issue out into the open.

Quarles has been researching water-damaged apartments and condominiums in

California, where an explosion of lawsuits against builders of leaky

buildings has the industry struggling to find solutions.

He said durability is a function of installation, detailing, products and

maintenance. His research looks at how water causes wood siding products to

degrade and warp.

of the National Association of Home Builders (NAHB) Research

Center said he recently finished a durability assessment project paid for by

the Department of Housing and Urban Development (HUD). The project focused

on 100 houses built from 1970 to 1975 and 100 houses built from 1990 to

1995. It included interviews with the homeowners and visual inspections of

the exteriors. Data will be available in the next several weeks.

Bill Rose, research architect at the University of Illinois at

Urbana-Champaign, is critical of the relationship between NAHB and HUD.

While both are aimed at improving housing affordability, each has its own

agenda, he said. " I don't think the quality of housing is enhanced under

this arrangement, " Rose said.

NAHB is a trade group that wants to increase affordability by avoiding

additional government regulations; HUD aims to provide low-cost housing for

the lowest-income people, few of whom will be buying new houses.

He also said that the study won't provide the kind of comprehensive data

that will give people a clear picture of the true condition of the housing

stock.

" I wish we were more rigorous in our approach to durability and asked

ourselves the hard questions -- we're dancing around the issue, " he said.

" Is this a dirty little secret or do we come out and say the third mortgage

holder takes a bath? "

Jim Buchta can be contacted at jbuchta@...