Water is the basis of life. Unfortunately, it can also cause untold devastation when not properly channeled. This is especially true in commercial construction, where water damage can compromise the longevity, safety, and energy efficiency of the entire structure. With this in mind, keep reading as we explore the importance of protecting commercial structures with robust water-resistive systems.
The Importance of Continuous Water Barriers
Water and moisture-carrying air leaks occur due to pressure differences between the interior and exterior of the structure. Some common culprits include strong winds, extreme interior/exterior temperature differences, stack effect, imbalances between supply/exhaust air systems, and hydrostatic forces. This can compromise the structural integrity of a building, destroy its energy efficiency, and compromise the health and safety of building occupants. As such, it is vital to fortify the building envelope by establishing a continuous air barrier. This involves installing a complete infrastructure of interconnected materials, assemblies, and sealed joints to prevent leakage from ever occurring.
Components of Complete Commercial Water Resistive Systems
From the foundation to the roof, every aspect of the commercial building’s design must be fully integrated to complete a water-resistive infrastructure.
Foundation
Water damage to the foundation of a commercial building is potentially catastrophic. Compromised foundations imperil the safety of the structure and can be expensive–or even impossible–to rectify. With this in mind, commercial buildings exposed to a high volume of groundwater must take measures to prevent water ingress at the foundation. Liquid flashing around the foundation is a preliminary measure that can keep concrete foundations from absorbing water. However, areas with greater hydrostatic pressure in the soil would be well-served to consider more comprehensive foundation waterproofing. This involves applying a series of water-permeable membranes to the foundation walls. When water flows through these membranes, it is directed to a series of drainage mats that send water into a subterranean pipe system and away from the building, providing the ultimate in foundational waterproofing.
Framing
Similarly to foundational water damage, water intrusion to the framing has potentially devastating consequences to the building. This is why oriented-strand board (OSB) framing is not recommended for commercial structures. A building using OSB framing will typically involve a series of small imperfections at joints that can expand after extensive exposure to air and moisture transfer when not properly sealed. In addition, as the wood framing absorbs moisture, it will face increased risk of rot, mold, mildew, and other moisture-related problems. Therefore, commercial buildings are better served to consider steel beams and insulated concrete forms (ICF) for creating a more airtight, water-resistive frame.
Doors and Windows
As the main apertures in commercial buildings, doors and windows are a natural location for water intrusion/extrusion. This is exacerbated when the frames are in poor condition. To ensure ongoing airtightness, many commercial buildings are installing hurricane-grade storm windows. Consisting of a structural steel frame and reinforced glass panels, these heavy duty windows offer the highest wind and impact resistance on the market, guaranteeing the ongoing integrity of the window system. For smaller, rapidly-emerging problems, water leak sealers can immediately bond to any door or window type, offering instant waterproofing of active leaks during inclement weather conditions.
Siding
Many types of wood and masonry siding products require extensive maintenance for water resistance. Wood siding must be painted or stained every other year, while masonry should be regularly sealed to prevent moisture absorption. Commercial buildings seeking the inviting curb appeal of these natural siding materials should explore innovative rainscreen cladding systems for greater water resistance. Rainscreen cladding uses a bearing wall, insulation layer, and cladding material fixed to the building via a support structure. This creates an air cavity between the load-bearing wall and cladding material for continuous ventilation. As the cladding material can be engineered in a wide selection of designs that closely mimic wood or masonry, the commercial building achieves stunning curb appeal with none of the threat of water damage.
Roofing
As a commercial building’s first line of defense against the elements, a quality roof is one of the most important components of a water-resistive infrastructure. Because commercial roofs will be much “busier” than typical residential roofs, the quality of the roof is tied to much more than the type of surface material it employs. Many commercial roofs are flat roofs and must be able to accommodate a heavy volume of rooftop traffic. In order to avoid water leaks caused by compressive forces, it is essential to have reinforced beams, girders, and structural b-decking to help mitigate heavy compressive forces. In addition, commercial roofs will typically feature a panoply of HVAC exhausts, skylights, vents, access hatches, and solar panels. Therefore, it is critical to choose the correct rooftop unit curb detail to ensure that the roof can support this additional equipment without compromising its water-resistive and insulative properties.
Protect Any Commercial Structure with a Comprehensive Water Resistive System
In order to guarantee the ongoing health, safety, and energy efficiency of a commercial building, it is vital to implement a comprehensive water-resistive system. By adhering to the professional tips listed above and other resources at Construction Daily, structural engineers can make any commercial building impervious.
