Issue link: https://hi.iaq.net/i/248503
www.epa.gov/iaq/moisture Chapter 3: Constructing to Prevent Moisture Problems If a commissioning agent is involved in the design and construction of a building, many of the quality assurance procedures for moisture control and associated measures could easily fall within the commissioning agent's scope. Introduction This chapter is for the people who turn design documents into buildings. More attention is being paid to moisture control during construction now than ever before because of increased concern about mold growth in buildings. In this chapter moisture control issues are divided into two major topics: During the initial meetings, the contractor can develop a plan to: • Protect the building from, and respond to, moisture problems during construction. 1. Control of water during the construction of the building. • Implement the moisture control elements, verification activities and commissioning activities detailed in the drawings and specifications. 2. Effective implementation of the moisture control requirements specified by the designers in the construction documents and associated contracts. Moisture control policies to protect the building during construction and to ensure the design has been effectively implemented should be in place before construction begins. After agreement on moisture control issues has been reached, the contractor must implement and verify the moisture controls required during construction and those required for the successful operation of the building. Erecting a building often involves several companies providing services from multiple trades. The general contractor has the primary responsibility and contractual obligation for the building's construction. The physical work often is carried out by specialized subcontractors such as landscapers, roofers, glazers, concrete and masonry contractors, steel fabricators, electrical contractors, insulation and waterproofing contractors and mechanical contractors. Providing moisture control during construction is largely the responsibility of the general contractor and the subcontractors. However, firms specializing in construction management or building commissioning may have responsibilities for moisture control. Control of Moisture During Building Construction Construction companies have always had to deal with moisture problems at the construction site. Materials and equipment get wet from: • Rain. The concept of commissioning traditionally has been applied to heating, ventilation, and air conditioning (HVAC) systems. Commissioning has been very effective in reducing problems and increasing energy efficiency and comfort. Over the past decade, this process has been extended to entire electrical systems; potable water, sanitary, drainage and irrigation systems; power production and cogeneration systems; the building enclosure; sustainable aspects of the project; and the entire building design process (ASHRAE Guideline 0: The Building Commissioning Process, GSA The Building Commissioning Guide, and the National Institute of Building Science [NIBS] Total Building Commissioning Program). • Water used in materials that are installed wet. • Leaks in temporarily or permanently installed plumbing. • Condensation in the building before it is enclosed. • Poor humidity control after the building is enclosed, but before the HVAC system is operational. As the site work begins and before the building is enclosed, contractors may use temporary site drainage, pumps, and dunnage and tarps to keep the site and materials relatively dry. Many of the materials used in the early phases of a project will not be damaged if they get wet, although some will have 67