Stucco Construction Problems Have Led to a Spate of Lawsuits

Tuesday July 20, 2004

Stucco construction lawsuits have become a major growth industry in recent years, with water damage and mold being the two chief complaints. 

According to the website of the city of Woodbury, Minn., problems have greatly increased in structures built since the late 1980s. 

In an October, 2002, report to the Center for Real Estate Education and Research, Ohio State University finance and business law scholar Elliot Klayman said the “number of lawsuits associated with toxic mold is growing exponentially and threatens to continue. Million dollar awards and settlements are now a reality” and mold has become a legal specialty. 

In March, 2003, the Associated General Contractors of America issued a 35-page publication on “Managing the Risk of Mold in the Construction of Buildings,” and the insurance industry has issued countless bulletins on the subject. 

Some insurance companies won’t write policies for structures with a past history of stucco problems, and, according to the television newsmagazine 60 Minutes, in some states, even a call from a homeowner inquiring about mold protection can lead to a carrier dropping a policy. 

Berkeley contractor Richard Schwartz said stucco is prone to leakage both from its inherent qualities and from construction shortcuts that leave the concrete-like finish susceptible to water intrusion—leaks, in lay terms. 

While declining to comment on any particular structure, Schwartz ticked off a list of common causes for stucco failures. 

• Inferior quality sand in the mix, “the number one cause of stucco failure;” 

• Use of too much or too little water in creating the stucco mix; 

• Installation of stucco in expanses of greater than 100 square feet without expansion joints to accommodate climatically caused expansion and contraction; 

• Installation of stucco in unbroken areas where the length to width ratio is greater than 2.5 to 1, rendering the material prone to cracks from expansion and contraction; 

• Failure to back the stucco with a double layer of Class B construction paper. 

Once water penetrates the stucco and construction and reaches the plywood or manufactured oriented strand board [made from wood scraps, usually from the creation of plywood], the danger of mold increases exponentially, Schwartz said. 

“Wood expands more perpendicular to the grain than parallel,” he said, and once water reaches the wood the plywood will expand. “If the contractor doesn’t separate each sheet of wood by an eight of an inch, expansion can cause the wood to buckle—which, in my opinion, is the single greatest cause of stucco cracks.” 

Improper installation of construction paper that creates a three-layer sandwich at boundary areas creates an environment where capillary action will draw water up and onto the wood. 

Schwartz said installation of so-called weep screeds—metal railings with evenly-spaced drain holes at the base of walls and overhangs—prevents water buildup behind the walls. Without them, “water will accumulate and the pressure will eventually force cracks in the stucco.” 

The critical factor for the growth of mold is humidity of greater than 20 percent inside the walls, he said. 

“Mold doesn’t colonize when the humidity is 19 percent or less,” Schwartz said. “Three factors critical for mold growth are humidity, a temperate climate—which we have here—and parenchyma, the carbohydrate in wood on which the mold feeds. The only thing that can prevent mold here is to deny it the moisture.” 

Another critical factor is the treatment of horizontal surfaces, where water can pool. Window ledges and roof surfaces offer points of critical vulnerability, and correct installation of waterproof seals is essential in preventing lengths. 

The use of low grade caulking compounds at window and roof joints is a common cause of leaks. High quality flexible sealants are one solution, but Schwartz said the preferred alternatives are mechanical seals such as overlapping or interlocking metal seals. 

But even with the metal seals, the adjoining construction paper should be covered by additional metal flashing to prevent water condensation. 

Recent testing on the Gaia Building using high-pressure water sprays at the windows and the exposure of construction paper at the corner of a window joint on the eastern wall indicates that windows have been a particular problem with the controversial structure. 

One clue that windows may have played a central role in the Gaia Building’s mold problems is found in the use permit the city issued authorizing Kennedy to build the Fine Arts Building on Shattuck Avenue, which imposed a special condition barring the use of stucco in that structure’s window sills.  

Current building codes don’t incorporate all the stucco construction safeguards, Schwartz said. “That’s because codes are political documents.” 

In June, 2002, the California Apartment Association’s Mold Task Force published a 33-page set of guidelines for assessing and correcting fungal contamination. The report identifies five molds most commonly associated with water intrusion: Cladosporidium, Penicillium, Aspergilis, Fusarium and Staphybotros chartarum—the most toxic of the lot. 

The Apartment Owners’ publication identifies the following symptoms of mold exposure: 

• Respiratory problems 

• Nasal and sinus congestion 

• Nose and throat irritation 

• Eye and skin irritation 

• Central nervous system disorders, including constant headaches, memory problems and mood changes 

• Aches and pains, and 

• Fever 

The greatest number of stucco-related lawsuits have been filed in Texas, where in 1997 then-Gov. George W. Bush ordered extensive repairs to the Governor’s Mansion following discovery of an extensive mold infestation. 

The next most mold-litigious state is California, according to a report by the National Roofing Contractors Association.?