A rainscreen is a type of wall system that has been designed to manage moisture and prevent water from penetrating into the building envelope. The term “rainscreen” describes the way that the system works: rainwater is kept away from the wall’s structural components, while an air gap provides ventilation and allows moisture to evaporate.

Rainscreen systems have been used in construction for over 30 years, and they are becoming increasingly popular in modern architecture due to their many benefits. These benefits include improved energy efficiency, durability, and longevity of the building envelope, as well as reduced risk of water damage and mold growth.

How a Rainscreen Works
The basic principle of a rainscreen system is to create a gap between the outer cladding layer and the structural wall. The cladding layer provides protection against the weather, while the air gap allows moisture that penetrates the cladding to drain away and evaporate before it can reach the structural wall. The air gap is created by installing vertical furring strips or horizontal battens over the structural wall. The cladding is then attached to the furring strips or battens, leaving a gap between the cladding and the wall.

The size of the gap can vary, but it is typically between 3/8″ to 1/34″. This gap is important because it allows air to circulate behind the cladding, which helps to dry out any moisture that has penetrated the outer layer. The outer cladding layer can be made of a variety of materials, including wood, metal, brick, or fiber cement. The choice of material will depend on factors such as the climate, the style of the building, and the budget.

Benefits of Rainscreen Systems
Rainscreens offer several benefits. The most important of these are significant reductions in the risk of water intrusion, increased durability and longevity of the wall system, and improved energy performance.

Improved Energy Efficiency
One of the main benefits of a rainscreen system is improved energy efficiency. By creating an air gap between the cladding and the structural wall, the system reduces the amount of heat that is transferred through the wall. This means that the building requires less energy to maintain a comfortable temperature, which can result in lower energy bills and reduced carbon emissions.

Durability and Longevity
Rainscreen systems also offer improved durability and longevity compared to traditional wall systems. By keeping water away from the structural components of the wall, the system reduces the risk of water damage and rot. In addition, the air gap allows moisture to evaporate quickly, which reduces the risk of mold growth. This can help to prolong the lifespan of the wall system and reduce maintenance costs over time.

Reduced Risk of Water Damage
One of the most significant benefits of a rainscreen system is the reduced risk of water damage. Water is one of the most damaging elements that a building can face, and traditional wall systems are often vulnerable to water infiltration. By creating an air gap and using materials that are resistant to water, rainscreen systems can help to protect the building from water damage. This can help to reduce repair costs and prolong the lifespan of the building.

Challenges of Rainscreen Systems
While rainscreen systems offer many benefits, they also present some challenges. One of the biggest challenges is ensuring that the system is properly designed and installed. If the system is not installed correctly, it can actually increase the risk of water damage by trapping moisture between the cladding and the structural wall. This can lead to rot, mold growth, and other issues. In addition, the system requires regular maintenance to ensure that the air gap remains clear.

For Further Reading:
• Wikipedia has an overview of rainscreen technology at: https://www.forbes.com/home-improvement/windows/types-of-windows/.
• “Understanding Rainscreens” by Fine Homebuilding is presented at their page: https://www.thespruce.com/most-popular-window-styles-1822931.
• Today’s Homeowner presents thoughts on this subject in their article, “Rainscreen Siding: What Every Homeowner Needs to Know”, found at: https://www.ecohome.net/guides/2263/high-performance-windows-what-to-look-for-when-shopping/.