Masonry and Mold
The concerns stemming from mold growth impact all sectors of the construction industry, but the understanding of the mold issue is only in its infancy.
The environments in which mold can grow and flourish involve food, moisture, moderate temperatures and oxygen. Moisture within buildings can come from numerous sources ? rain penetration, condensation, improperly sized air conditioners, showers and baths, and zoned HVAC systems.
The increased demand for builders to erect structures faster increases the possibility of construction errors that may result in leaks in both the structure and plumbing. Continuing efforts to reduce the cost of initial construction has also resulted in greater use of lighter-weight materials that provide more food on which mold can grow.
A drive toward energy efficiency requires that air leakage in structures be reduced. The deleterious side effect of this practice is that wall systems are prevented from "breathing," which historically allowed moisture to escape rather than remain trapped to support the formation of mold. Further, there is no feasible method of completely eliminating mold from the environment.
Impact of Mold
Nationwide, the number of mold court cases has increased dramatically, resulting in a staggering cost to the construction industry. Hundreds of millions of dollars are spent each year on mold litigation, claims and remediation. Inhabitants of building where mold growth is prevalent have experienced a wide range of physical reactions, varying from none to severe depending upon the individual, and the concentration and type of mold. There are thousands of different types of mold and the health effects from exposure to these molds are the subject of scientific debate.
While the mechanisms that can lead to mold growth are well understood, the reasons for observing and hearing about more prevalent problems in recent years are not. It is likely that the increased frequency of the presence of mold in buildings is a byproduct of the evolution in how structures are designed and built. Unlike other deleterious substances, there is not an established permissible exposure level for mold. Many have adopted a zero tolerance level, which is impossible to comply within an environment where mold is omnipresent.
Unlike with asbestos and other materials, which have been the focus of "toxic" tort litigation and construction defect claims, mold is naturally occurring. The three elements necessary for mold growth ? food, oxygen and water ? are found in every building. Mold is everywhere. Because mold is always present, everyone has been exposed to mold in some form and to varying degrees.
Although toxicity is plotted on a continuum and depends on levels of exposure or inhalation, the widely accepted perception of mold is that it is "toxic." Anyone suffering adverse health effects or property damage attributed to mold growth is a potential claimant. Such claims may be brought against anyone involved in the design or construction of a building that is found to facilitate the growth of mold. Since mold is omnipresent at one level or another, all buildings are included.
Because nearly anyone in the construction industry can be the target of such litigation, architects and engineers need to consider the potential for mold growth during the design phase.
Design professionals should take a proactive approach to the mold problem. They should work to prevent water infiltration, excessive humidity and condensation, which are the key factors in the development of mold. Specifically, architects and engineers need to counsel and advise clients regarding potential risks and benefits associated with specific designs and material selections and seek to design buildings to control mold growth by limiting water infiltration and high humidity levels. To this end, design firms need to educate themselves about how, why and where mold grows and what measures can be taken to reduce the threat of mold developing. Increased awareness of the potential problem coupled with an understanding for how detailing, material selection, and HVAC considerations will affect ideal mold growth environments will reduce mold occurrences and thus limit legal risks and liabilities.
Attributes of Masonry
The challenge is to reduce the potential for future mold growth in finished structures. Selecting masonry as a building material will not, by itself, guarantee that mold will not become a problem in a building. However, masonry does have inherent characteristics that reduce the potential of mold formation not found with organic materials: It does not provide a food source for mold, it does not rot, and it can be cleaned. While masonry is not the only answer ? it is an excellent part of the answer.
The masonry industry is dedicated to providing technical information on the proper design and construction of masonry structures to keep moisture out of the building where it can result in damaging effects.
About the Author
Masonry, the official publication of the Mason Contractors Association of America, covers every aspect of the mason contractor profession - equipment and techniques, building codes and standards, business planning, promoting your business, legal issues and more. Read or subscribe to Masonry magazine at www.masonrymagazine.com.