Project risks take many forms in the design and construction of large facilities. Precast concrete is sometimes viewed as a riskier form of construction by design professionals because it requires an early commitment during the design phase and many architects are unfamiliar with how precast buildings are designed and constructed. In reality, precast concrete construction is an inherently less risky form of construction for both owners and architects:
Budget and Schedule Compliance
For the owner and design professional, budget risk is one of the most significant factors they face in meeting the building’s program and aesthetic needs. Because precast is a plant-built project, precast producers can make schedule and cost assessments in the late schematic and preliminary design phases to help design professionals assess budget compliance. Total precast (where precast concrete components are used for both the structure and enclosure of the facility) can represent the dominant portion of the construction budget. When the intricacy of the exterior wall panels can be tied down early in the project, precasters can estimate fabrication and erection costs with a high degree of accuracy.
Detailing Risk Reduction
Building façades are often composed of multiple products with varying degrees of expansion and contraction. A façade composed of a stone or concrete masonry, brick, or other elements will require slip joints to accommodate differential movement, and regular expansion joints depending on the size and nature of the product. Even the best architectural documents can suffer from poor coordination and improper installation in the field, causing the design professional lost time in coordination and problem resolution, as well as potential liability if the products are installed improperly. Precast concrete allows the creation of multi-part façades without these detailing risks. Precast can affordably mimic most stone products in concrete, and thin-brick or veneer stone can be embedded in the face of the panel for an almost limitless variety of appearances.
Elimination of Cavity Wall
Few aspects of construction pose as much risk for design professionals as the cavity wall. Brick veneer cavity wall construction relies on the skill of the mason to install the systems so that the cavity is clear, the backer membrane is continuous, dew point issues are managed, and cavity moisture is weeped effectively to the base of the wall and out of the cavity. Even when properly designed and installed, mortar joints, waterproofing, and weeping systems deteriorate over time and allow more moisture to become trapped in the cavity. Precast concrete construction eliminates cavity wall risk. High performance precast walls consist of interior and exterior wythes of concrete sandwiched around a core of continuous EPS or XPS insulation. High-strength concrete allows little moisture penetration, so dew-point and cavity moisture problems are eliminated.
Precast concrete is plant-produced and trucked to the jobsite when needed. Unlike poured-in-place concrete, masonry, or exterior insulation systems, the product can be installed in cold (or even freezing) weather, eliminating the cold-weather procedure delays, general conditions claims, and potential change orders associated with other products.