The design issues regarding the transmission of vapor through wall envelopes continue to plague home builders regardless of the cladding used, and further bolster the argument that there is no alternative to sound construction practices. Builders who fail to grasp this lesson could face the same fate as Zaring Homes of Cincinnati, Ohio.

 

Given that the wall assembly described below utilizes a weather barrier in a conventional configuration behind the brick cladding, should the EIFS industry now question the recent focus on secondary weather barriers and their relevance to EIFS applications?

 

 

Mold & Moisture Bankrupt Big Builder

 

How quickly after a new home is built can the walls develop serious mold problems? In the case of Cincinnati builder Zaring Homes, the answer was ten weeks. Zaring Homes was building over 1,500 homes a year during the mid-1990s, with annual profits of over $6 million, and when dozens of its new homes became moldy in 1999, the company committed itself to fixing the problems. But the remedies soon became so expensive that the liabilities drove the company to bankruptcy.

 

Standing water. The first residents began moving into one of Zaring's new-home developments, Parkside, in Mason, Ohio, in May 1999. "In late July, the homeowners complained of wet carpet," says Gregg Nicholls, chief building official in Mason. "They saw mold on the subfloor. In August, holes were cut in the drywall to inspect the framing, and there was a quarter inch of standing water in the bottom of the stud cavities." Since Ohio was suffering a drought that summer, the amount of water was surprising. "We were able to wring water out of the fiberglass insulation," said Stephen Vamosi, a consulting architect at Intertech Design in Cincinnati.

 

Water accumulated in the exterior walls of dozens of new homes constructed by Cincinnati builder Zaring Homes. The brick veneer on many of the homes was removed as part of the investigation to determine the source of the moisture.

 

It soon became apparent that dozens of homes had similarly wet exterior walls. Consultants hired by the homeowners blamed poor detailing of the brick veneer. "We believe that wind-driven rain is the source of the moisture," says Timothy Sullivan, an attorney at Taft, Stettinius and Hollister, the Cincinnati firm representing many of the homeowners who are suing Zaring. "The brick is either installed flat against the sheathing, or the air space is filled with mortar."

 

But consultants hired by Zaring Homes and its insurance company concluded that the source of the water was exterior vapor, which entered the walls through permeable sheathing and condensed on the back of the polyethylene under the drywall. "Every one of the affected houses had air conditioning," says Vamosi.

 

Expensive repairs. Whatever the source of the moisture, the results were devastating for Zaring Homes. "Zaring did an incredible amount of remediation on a lot of homes," says Nicholls. "They stripped off the brick and the sheathing, so that the studs were open to the exterior. They pulled out all the insulation, put a mold-protective Kilz paint on the inside of the stud cavities, and rebuilt the walls." After the value of Zaring stock plummeted, all of the assets of the company were sold to Drees Company in January 2001, before remediation work was complete. "Zaring Homes went out of business because they have a $20 to 50 million liability here," says Joe Lstiburek, one of the consultants involved. "Hundreds of homes are potentially involved. To fix the problems would probably cost $60,000 to $70,000 per home."

 

The Zaring story shows how small decisions can have enormous consequences for a builder. Early on in the moisture investigation, Vamosi gave some advice to Allen Zaring, the founder of Zaring Homes. "I told him, 'If you add another inch and a half of insulation to the walls, you will avoid the dew-point conditions,'" recalls Vamosi. "Zaring answered, 'I can't do that because it costs too much. No one else is doing that.' But look what happened to Zaring."

 

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