The Benefits of Rainscreen Design

Rainscreen systems offer multiple advantages, including enhanced aesthetic flexibility and sustainability. Sustainability, at its core, encompasses energy efficiency (operational carbon), the use of recycled and recyclable materials (embodied carbon), and durability (long-lasting, healthier buildings). By employing multiple functional layers, rainscreen designs contribute to long-term structural resilience and energy conservation.

A tube seal insulation fastener attaching continuous insulation. The green tube acts as a gasket to seal off the screw penetration of the AWRB.

A tube seal insulation fastener attaching a ventilated hat channel. The green tube acts as a gasket to seal off the screw penetration of the AWRB and also creates a thermal-break by separating the steel fastener from contacting the steel channel.

Evolving Building Codes and Multi-Layered Rainscreen Design

The term “air barrier” only became commonplace in North American construction a few decades ago. Previously, structures were designed to allow air to pass through the building envelope to remove moisture and prevent condensation buildup. While this approach facilitated drying, it compromised energy efficiency as conditioned indoor air freely escaped.

The introduction of air barriers, now mandated by code, significantly improved energy efficiency by reducing air leakage. However, new challenges arose—trapped vapor and moisture inside the envelope led to mold growth, rot, and indoor air quality concerns. Since 2012, the International Energy Conservation Code has required continuous insulation (as defined by ASHRAE 90.1), which not only enhances insulation but also shifts the dew point outward, reducing condensation risks.

The integration of air and weather barriers with continuous insulation proved beneficial, but it necessitated new cladding attachment methods. Rainscreens address this by allowing cladding to be installed over the air, water, and thermal control layers while also facilitating drainage and ventilation. This approach applies to various rainscreen assemblies, including aluminum composite material panels, metal panels, ceramics, adhered masonry (stucco, stone veneer), and masonry cavity walls.

A ventilated rainscreen façade showing all control layers including AWRB (air & water resistive barrier), continuous insulation, ventilated hat channel for drainage and ventilation, and outer façade. Note the green tubes gasketing against water and air penetration of the AWRB and forming a thermal-break between the steel channel/façade and the screws. Point loads of screws in this type of assembly generate minimal thermal bridging, often less than 5% R-value reduction.

Challenges in Cladding Attachment Over Continuous Insulation

As the adoption of rainscreens increases, the challenge lies in securing these multi-layered systems effectively. While fasteners and anchors can support the weight of cladding over the air gap, their penetrations through air and water-resistant barriers pose risks of leakage. Additionally, thermal bridging through fasteners undermines the insulation’s effectiveness. Historically, the industry overlooked these issues due to a lack of solutions addressing water, air, thermal, and structural integrity simultaneously. However, continued innovation has led to the development of advanced fasteners and anchors that mitigate these concerns.

Innovations in Fastener Technology for Rainscreen Systems

Screws and metallic fasteners are essential for securing rainscreen structures against gravitational and wind loads. While non-metallic fasteners exist, they often lack the capability to drill into substrates such as steel studs, masonry, or wood, particularly under fire conditions. A new solution involves incorporating non-metallic components into metallic fasteners to reduce thermal bridging and self-seal penetrations through air and water control layers.

For instance, tube seals can be added to insulation fasteners. These seals are rigid enough to pierce through insulation but flexible enough to compress against the air/water barrier, forming an effective gasket that prevents air and water infiltration. This concept extends to various cladding attachment systems, such as hat channels with pre-punched holes for tube seal fasteners. These channels include slots to facilitate drainage and ventilation, ensuring optimal rainscreen performance.

Rainscreen design isn’t just for metal panel facades, rather adhered masonry such stucco or stone veneer as well as brick or stone cavity wall construction can all be designed as a drained and ventilated rainscreen assembly using tube seal style fasteners to reduce water and air leakage and thermal-bridging.

Adhered masonry systems like stucco and stone veneer can also function as rainscreens when installed with entangled filament mesh, creating a drained and ventilated channel beneath the lath and base coat. In this setup, tube seal fasteners can be used with galvanized lath washers to seal screw penetrations while securing the lath and base coat over the air gap.

Masonry cavity walls, a common rainscreen type, consist of an internal structure (steel studs, wood studs, or block) and additional air and water control layers. The exterior brick wythe transfers vertical loads to the foundation, while lateral loads are managed by brick anchors. Advanced brick anchors now incorporate tube seals to self-seal penetrations, minimize thermal bridging, and prevent direct contact between embedded wire ties and structural screws through polycarbonate tubing.

Importantly, these tube-seal-based solutions retain metal fasteners at their core. This ensures that in the event of fire, the cladding remains securely attached to allow safe evacuation without façade delamination.

Smart Rainscreen Cladding Design

Effective rainscreen design addresses water drainage and ventilation to maintain dry walls, reduces thermal bridging through continuous insulation, and provides structural support against gravity, wind, and fire. While incorporating these control layers adds cost, fasteners and anchors must remain simple, efficient, easy to install, and cost-effective.

A tube seal fastener or anchor system offers an optimal solution, balancing performance, affordability, and ease of installation. By leveraging these innovations, builders can ensure that modern rainscreen systems meet stringent performance demands while supporting energy efficiency and long-term durability.