Mold Prevention: Limiting Your Exposure

Abstract

Mold growth within buildings is not a new problem, but mold is attracting increased attention from media, litigators, and owners. Because of susceptible building materials and increasing dependence on artificial ventilation, we can expect risk of mold infestation on building interiors to increase. Mold requires four elements: warmth, moisture, nutrients, and spores. Problems can start with moisture trapped in wall or floor assemblies during building construction or by improperly installed or placed vapor retarders. Other sources include moisture allowed through ineffective wall cladding systems, improperly designed or constructed ventilation and humidification systems, and mold-susceptible materials. The prevention of mold growth during the design and construction phases does not involve new or unproven methods. Current means for mold prevention are remarkably similar to recommended construction practices of the past. Today, however, the effects of aberrations from good design and construction practices can be extraordinary in terms of money and schedule. Introduction of a small quantity of moisture can create large amounts of mold growth in modern construction. Designers can reduce the risk of mold growth by specifying suitable materials, proper wall and roof configurations, and the construction sequence when appropriate. Designers should also encourage monitoring of construction and interior humidity. Building owners and developers can help by encouraging a single contractor for construction of the building envelope and by allowing a schedule to permit good construction practices. General contractors must coordinate trades and construction sequences to protect the building at all times. All parties can reduce the likelihood of mold growth by understanding the conditions necessary for mold growth and avoiding situations that encourage that growth. This paper will review mold problems based on experience with a building that developed mold growth during the construction phase. Mold growth resulted from mishaps with contractor solvency, mold-susceptible materials, and improper temporary protection. Each problem that contributed to the mold growth was preventable. The paper will address the specific pitfalls that plagued this construction project and will outline steps designers, owners and contractors can undertake to prevent similar conditions.