Before Alabama’s AGC even selected its design-build team for its new headquarters, it decided it was going to take every possible precaution to build a mold-free building. As a result, avoiding problems with mold –– both short- and- long-term –– were major considerations in the early design phase of the project.
The AGC’s construction team –– owner and general contractor, Rives Construction Co. and architect KPS –– all were aware of the problems with mold and were constantly on the lookout for ways to avoid its problems. KPS hired a building envelope specialist to consult on the mold issue before designing the building. Rives Construction sent the project manager to a mold seminar held at the Alabama AGC office and all specialty contractors were informed of the emphasis on mold in the project.
“We started working with mold considerations at the earliest stages,” said Henry T. Hagood Jr., Alabama AGC executive vice president. “As an owner, we let everyone on the construction team know that avoiding mold problems was a top priority. At the same time, we knew we had to use common sense because we had budget and design considerations.”
“The design of the building incorporated elements to protect against a mold problem,” said Ken Rubsamen, an architect with KPS. “We were looking at not building up costs, yet still providing as good a shell as we could. We have basic details that we use that we worked up with Hixson-Smith [now Hixson Consultants, Inc.]. We also had several meetings with Hixson-Smith because they are building envelope specialists and we wanted to have the proper details for this project.”
“We were in some meetings with KPS in the planning stages going through the details,” said Ben Hixson, president of Hixson Consultants. “You can be 100 percent successful with some planning during construction. The owner should identify a goal of zero moisture tolerance with the architect and the rest of the construction community at the beginning of the project.
“A lot of owners aren’t sophisticated enough to know that the problem exists,” Hixon said. “Thankfully, most contractors are aware of what we’re talking about. At first you have to educate the owner, work with the design and then it’s a discipline at developing a concern and an understanding and a follow-through to see that [the planned anti-mold measures] happen on a regular basis.”
The Alabama AGC became aware of the mold problem in the usual way –– through media outlets and a growing number of educational opportunities at association meetings.
“Newspaper headlines and television news programs such as 60 Minutes have brought national attention to the issue of mold,” said Jack G. Kowalski, an attorney with Burr & Forman LLP, “…and as a result, have created somewhat of a fear among consumers. Mold litigation may surpass asbestos as a litigation problem.”
Kowalski said that at the end of 2003 there were 10,000 mold cases pending across the United States. There were 32 lawsuits nationwide where claims or jury awards exceeded $1 million, he said. Claims jumped to $8 billion by the end of the year.
Unlike asbestos, where there is a huge manufacturer to target, defendants in mold lawsuits are wide ranging and include developers, general contractors, specialty contractors, building product manufacturers, architects and engineers, Kowalski added.
“While it is too early to determine whether mold-related claims will replace asbestos lawsuits at the top of the hierarchy of mass toxic tort cases, it cannot be disputed that mold-related claims have shaken the construction industry,” he said. “Consequently, virtually every player in the construction process, from owner to contractor to design professional, must view the risks associated with mold seriously and take a proactive approach to adequately guard against such risks.”
From the parking lot, to the carpet adhesive, to the roof, the Alabama AGC State Headquarters building was designed to shed water and resist mold.
The AGC began the design process before the team of Rives Construction and KPS was hired. Uday Bhate, of Bhate Engineering, walked the property to identify drainage issues while the AGC staff was still working out the details to buy the land.
“I walked it and did a preliminary and then some supplementary work once the building location was defined,” Bhate said. “You had issues with rock and you had a creek on the left hand side and there was an issue related to disturbing the creek. A lot of things had to come together to make it work.”
Alabama’s AGC State Headquarters sits near the bottom of a steep hill with rock just below the surface. the organization knew that keeping moisture out of the building would be crucial to eliminating mold.
“We were concerned that as the water percolates it is going to hit that rock and come toward the building,” Bhate said. “We put French drains on each parking tier and a foundation drain in the lower level of the building so that water is picked up and taken out. We went through a thoughtful process. We wanted to catch all of that along the parking lot before it got to the building and get it out in a controlled manner.”
Water on the ground presents one set of problems. Water on the building presents another.
“The design of the building incorporated elements to protect against a mold problem,” said Rubsamen.
One of the first considerations for cost was the glass that covers most of the outside of the State Headquarters building.
“Originally the concept was to use a storefront glazing system,” Rubsamen said. “But a storefront really is for a single-floor application and we have a two-story building. What occurs in a two-story building is you have more volume of water to deal with and that would have been overtaxing the storefront. We changed to a curtain wall system. In a storefront system all infiltrated water is channeled to the bottom before being weeped, whereas in a curtain wall application water is drained at each horizontal framing member.”
“Curtain wall was more expensive and added $30,000 to the cost of the building,” said Jim Rives, Alabama AGC director of special projects. “But we considered the cost worth it. We were able to save money on other design items such as eliminating the sprinkler system.”
“A lot of times we recommend not putting in sprinkler systems,” said Rubsamen. “We design the building to not require sprinklers because they can cause water intrusion. The concrete columns are basically fire resistant and the areas between the tenants and the corridor are one-hour fire rated. We considered a lot of different design elements to keep from having to put a sprinkler system in.”
Code required the design to include a 10-inch water line outside the building instead of a six-inch line, but that cost still was $20,000 below the cost of installing a sprinkler system.
Other design considerations:
• A standing seamed metal roof rather than flat roof. The roof also has an extended eve to keep water from sheeting down the glass. Bitumen underlayment was used under the roof because it is stronger and repels water better than felt.
• The building is slab on grade with a foundation wall facing a sloping site.
• Stucco was used instead of EIFS.
• The AGC cancelled a planned 1,000-square-foot storage area below the building and instead built a separate storage facility on site.
• A special paint was used on the drywall that runs from the floor to the bottom of the windows on the exterior of the building.
• Acton Flooring installed the carpet using “adhesives, patching compounds and flooring materials that are not a food source for mold,” said Dawn Cox.
Hixson said Acton’s approach is the best because proper sequencing and precautions during construction are crucial to avoiding later problems with mold.
“One of the things that we stress is that during construction you are protecting the walls from moisture,” Hixson said. “We see a lot of situations where drywall is being put in before caulking and even roofing is finished. Any opportunity where you are allowing organic materials to receive water that may not quickly dry out is a risk for mold growth.”
And then there is HVAC. Air conditioning automatically dries out air and without humidity control there is no mold control.
“The actual worst moisture problems that we have seen apart from the real obvious hole in the wall has been due to unbalanced HVAC systems in the South,” Hixson said. “I’ve seen far more damaging problems with condensation with that than with rain water leaks.”
Since the Alabama AGC Statewide Headquarters building has empty space, the organization had to be careful to properly balance its HVAC system and properly heat and cool even the unoccupied space.
Of course, the design-build team also was constantly aware of quality control, inspecting during construction and remediating any problems.
“It is now incumbent upon the contractor to be more proactive and force the designer to do their job. The contractor should speak up, say ’This isn’t done right,’ and put that in a letter and keep it in a file. Architects won’t draw flashing; press them on that. Keep materials dry and document the effort.”
Kowalski pointed out that all molds are not considered toxic and only toxic molds, such as stachybotrys and aspergillus, are drawing the attention of plaintiff’s attorneys who contend these molds are causing serious health problems.
He said most claims that affect our industry contend that a construction defect permitted moisture to collect in the building, allowing the spread of mold. Of course, there has been moisture and mold in buildings since there have been buildings. So, why are mold-related claims becoming so prevalent? Kowalski believes there are some main reasons:
• Advanced construction techniques that encourage enhanced energy conservation, but drastically hinder the escape of water and moisture from within the building.
• Proliferation of building materials containing organic sources that serve as a prime “feeding ground” for, and encourage the spread of, mold.
• Inadequate, insufficient or improper design details, especially in areas where water intrusion is likely to occur, such as roof angles, eaves and windows and doors.
• Inadequate, insufficient, or improper protection of construction materials –– particularly interior finish materials such as drywall –– from the elements.
• Recent large jury awards and the ensuing media attention.
While toxic mold litigation is relatively new, the basis of practically every mold-related claim is a construction defect, and construction defects have been litigated for years, Kowalski said.
“In essence, the plaintiff in a mold-related claim typically contends that a construction defect, whether in the actual construction or design, created a condition that allowed moisture to collect within the building, which promoted the growth of mold,” he said. “As more and more general contractors tend to subcontract most of the actual construction work, the subcontractor often becomes the focus of the attention.
“Mold-related claims, like other construction defect claims, often involve a host of litigants on both the plaintiffs’ and defendants’ respective sides. Plaintiffs in mold-related cases include property owners, developers, tenants, employees and other individuals whose workplace may be located within a building claimed to be infested with mold. While it is estimated that homeowner claims make up approximately 50 percent of all mold-related claims, the trend is definitely moving into larger scale markets, including both public and private commercial projects.”
Kowalski said that a lack of guidelines is at the heart of the toxic mold litigation problem.
“Despite the rapid increase in the number of mold-related claims and lawsuits, there are no federal guidelines concerning mold remediation or mold exposure limits,” he said. “In fact only a few states have adopted guidelines concerning mold exposure.” (Alabama has no such legislation on the books and as of early 2004 was not considering any.)
That could be changing, however. Kowalski said the federal government is considering establishing guidelines relating to mold and the removal of mold from public buildings.
He added that with the ever-increasing threat of litigation, it is crucial that owners and contractors take steps to avoid mold-related risk during construction.
For more information, visit www. alabamaagc.org.
(Bill Caton is of the Alabama AGC and is a frequent contributor to CEG.)
Today's top stories
