Integrated Rainscreens with Permeable WRBs: Versatility for Siding/Facade Applications

The building industry has come a long way with improving water-intrusion management for different projects, and multifamily buildings are no exception. Many new designs routinely incorporate a combination of rainscreen cladding on the exterior and WRBs to protect the structure. But moisture is still a problem that needs to be taken very seriously to avoid structural damage, shortened life of paints and cladding, and the potential health hazards that stem from rot and mold. As noted earlier, one of the more common reasons that structures suffer from water intrusion is a mismatch between rainscreen materials and WRBs, and the complex task of making sure specified products work together in a project. A few manufacturers have started to address this challenge with integrated systems that allow builders to specify rainscreen and WRB materials that have been designed together as one material.

While integrated systems will vary between manufacturer, the common goal is to provide a moisture management system with building wraps and accessories (e.g., sealant, tapes) and an attached rainscreen system. Essentially, an integrated system provides builders one-stop shopping from a trusted supplier.

New integrated moisture management systems tackle water intrusion in a variety of ways. Some suppliers have focused on finding ways for building wrap to drain water from the surface more quickly, or through better seam sealants and application techniques.

New designs in drainable building wraps have two key layers: a water-resistant layer and a drainage gap that helps water quickly drain from behind the cladding. The combination of these layers is considerably more effective at removing water than traditional wraps, which are designed more so to keep the water out of the structure but not to specifically drain it.

Another change in moisture management systems involves the building wrap seams, which need to be taped properly to prevent water intrusion. Building wraps, and especially drainable wraps, need to be applied in a shingle style, starting at the base and working upwards. This layering style helps ensure that water does not get into the seams as it runs down the wrap. Drainable wrap, however, presents a challenge when it comes to securing a tight seal because of the drainage gap. If the wrap is not applied properly, taping gaps can form, and eventually water and debris can get caught in the gaps. If this happens, the tape can fail, and the wrap will be more prone to detach from the building structure.

With an integrated system, the manufacturer will provide a tape that is designed to seamlessly and securely seal the wrap. For example, a tape may be double sided to ensure the best adhesion and avoid potential tape gaps.

Benefits of an Integrated System for Multifamily Residential Projects

Integrated systems have numerous benefits for multifamily projects, namely in terms of the time and cost savings that come from using a single solution for multiple material applications and from specifying from a single source. Let’s take a closer look at some of the other advantages of using an integrated moisture management system.

• A single solution for multiple material applications means that builders can avoid the problems that come from different cladding assembly attachment requirements. For example, rather than needing both a WRB and furring strips, which results in uneven assembly thicknesses, integrated solutions allow for a single WRB that works with all cladding options from the same supplier.
• Single-source specification removes any uncertainty about how materials will fit together and eliminates project delays that frequently happen with multiple suppliers that have different delivery timelines. This in turn can save on overall project costs and help ensure that project components are installed on schedule.
• Integrated moisture management systems are easy to install. With one-stop shopping, all required components are guaranteed to work together, which can make installation both quicker and easier.
• New permeable WRBs are designed to optimize drying time. This adds to their versatility when used with associated rainscreen applications.
• Finally, permeable WRBs are proving to be high-quality, durable products that protect the building structure better and longer than traditional materials.

For multifamily residential projects, especially larger-scale projects, each of the above points can help with cost savings when compared to projects that use older materials sourced from multiple suppliers.

Extruded Aluminum Trim, Building Exteriors, and Moisture Management

Extruded aluminum trim is typically used by architects to add clean details to a project’s interior and exterior and complement a moisture management system. For exteriors, extruded aluminum trim can help provide aesthetic variety and cohesion for exterior panels and other facade materials. Some manufacturers also supply moisture management solutions that complement their trim lines and help meet code requirements.

As discussed earlier, builders of multifamily projects are increasingly including moisture management systems as a way of protecting the building assembly, increasing the lifetime of the building in general, and improving the health and well-being of the building occupants. Keeping water and moisture out of a building is a high priority, especially in regions where rain, wind, and snow are common, but also in areas where weather patterns have been shifting and precipitation is increasing. Exterior cladding, such as rainscreens facades that serve as a first line of defense against moisture, combined with a properly installed WRB that protects the building assembly and allows any moisture that gets through the cladding drain out of the building system, helps keep a building dry. But an often-overlooked aspect of the water management system is the trim.

Trim is an important aesthetic aspect of any building, but it can also complement moisture management, either by deflecting water to more protected parts of the building’s siding or aiding in water drainage off of the building. Extruded aluminum trim is a popular choice for many different projects, from single-family and multifamily residential to light commercial. It is sustainable, relatively inexpensive, generally easy to install, durable, and delivers a clean, modern aesthetic when used in conjunction with certain exterior cladding. Moreover, it is usually designed to work with siding from a wide range of manufacturers, and it can be used in many different ways depending on the project.

On multifamily residential projects, extruded aluminum trim offers modern aesthetics, durability, and sustainability, all while adding to the building’s moisture management system. It also has the benefit of easier and faster installation, which is a welcome feature for any project but especially for larger-scale buildings.

Modern trim is often used on multifamily residential projects to provide clean lines as well as assist with water drainage.