Rainscreens 101: Essential Moisture Management for Modern Building Envelopes
In the evolving world of construction, effective moisture management is more crucial than ever. With advances in building codes, increased climate variability, and greater expectations for building longevity, construction teams are increasingly focusing on building envelope solutions to protect structures from the damaging effects of water infiltration. One of the most reliable ways to achieve this is through a well-designed rainscreen system. Rainscreens, which offer drainage and ventilation pathways, prevent moisture buildup and protect structural integrity over time.
Why Moisture Management Matters In every climate, moisture is a persistent challenge for buildings. Whether it comes from rain, snow, or humidity, moisture can penetrate cladding and damage the underlying structure. Without effective moisture management, buildings risk mold growth and material deterioration, which lead to increased maintenance costs and can even impact occupants’ health.
To address this, building codes have evolved to require or encourage moisture control measures that extend beyond traditional water-resistant barriers (WRBs). Rainscreen systems, which are designed to create a gap for drainage and ventilation between the cladding and building structure, are one of the most effective solutions for controlling moisture. By helping to prevent water from reaching the interior walls, a rainscreen system safeguards the entire structure, enhancing building resilience and occupant comfort.
What Is a Rainscreen? Put simply, a rainscreen is a system designed to manage moisture by creating an intentional gap between the exterior cladding and the primary structure of a building. This air gap allows for two primary functions:
This design approach allows builders to manage water in a way that both protects structural components and contributes to the energy efficiency of the building.
Rainscreen Design Options: Exterior Framing vs. Exterior Cladding When it comes to rainscreen systems, there isn’t a one-size-fits-all approach. Builders and architects can choose from various design methods to create a building envelope that efficiently manages moisture, enhances durability, and meets aesthetic and performance needs of their project.
One of the key differentiating factors for rainscreen systems is where the system is positioned relative to the insulation and cladding. This decision impacts the wall’s thermal performance, moisture management, and ease of installation.
Exterior Framing Applications
In this method, the rainscreen is part of the external framing layer. This design is effective when aiming to minimize thermal bridging, as it allows for continuous insulation across the exterior of the frame.
ClarkDietrich’s ProChannel® Ci Cladding Support with Grip-Deck TubeSeal® technology is a great example of this type of approach to rainscreen design. Designed to work with continuous insulation, ProChannel Ci provides a stable attachment point for cladding while establishing a 7/8” vented rainscreen air cavity. The self-sealing Grip-Deck TubeSeal fasteners minimize penetrations through the insulation layer, which reduces thermal breaks, enhances energy efficiency, and contributes to a high-performance envelope.
Z-Girt Systems are another alternative for exterior framing rainscreen applications. These metal channels support cladding and maintain a clear space for insulation, providing effective rainscreen capability by allowing air and moisture to move freely. Z-Girt systems are particularly beneficial for in-line framing with insulation, offering simplicity and durability in installation. ClarkDietrich Z-Girt is available in various depths from 1-1/2" to 4" to match common exterior insulation thicknesses, includes slotted holes in the web for moisture weeping, and can be installed in either a horizontal or vertical orientation.
Exterior Cladding Applications
For projects where the rainscreen is positioned behind the final cladding layer, builders might prioritize creating a drainage and ventilation layer directly behind the external finish, such as stucco, stone veneer, or brick. In fact, a large portion of the U.S. is now required by code to provide a capillary break behind these “absorptive claddings” to facilitate both drainage and drying.
ClarkDietrich’s E-Screen system is designed for precisely these types of exterior finishing applications. E-Screen is a polypropylene entangled mesh rainscreen that has a 95% open design, providing a continuous capillary break for intruding moisture to drain away from the wall system while accelerating drying time.
Responding to customer demand for a complete, easy-to-use system, ClarkDietrich recently added two new components to the E-Screen system—Top Vent Track (TVT) and Drip Flashing for Rainscreen (DFLRS). TVT provides a secure connection at the top of the wall for ventilation, while the DFLRS provides a secure connection at the bottom of the wall to facilitate proper drainage and ventilation.
Choosing the Right Rainscreen Solution for Your Project Selecting the best rainscreen system depends on a variety of factors, including climate conditions, building height, wall assembly type, and the cladding materials used. For instance, in regions with high humidity or frequent rainfall, an exterior cladding application like E-Screen may be optimal for managing moisture behind absorptive materials like stucco or stone veneer. Conversely, for projects focused on maximizing thermal efficiency with continuous insulation, exterior framing options such as ProChannel Ci can provide robust moisture management while minimizing thermal bridging. Each ClarkDietrich rainscreen solution offers unique advantages, so builders can find a system that best fits their specific performance and design requirements.
For more information on ClarkDietrich rainscreen solutions, visit www.clarkdietrich.com/products/rainscreen-solutions or contact our team to discuss how to select the ideal rainscreen products for your next project.
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