A rain screen is a wall design approach using a ventilated air gap between the exterior cladding and the water-resistive barrier beneath it, allowing any water that gets behind the cladding to drain and dry out through natural airflow rather than remaining trapped against the wall assembly.
This approach treats the exterior cladding as the first line of defense against most rain, while the drainage gap and water-resistive barrier behind it serve as a genuinely effective backup system for the water that inevitably gets past the cladding during wind-driven rain events.
Building science has increasingly emphasized rain screen design, particularly in climates with significant wind-driven rain, since this ventilated gap meaningfully improves a wall’s overall moisture management compared to cladding installed in direct contact with the barrier beneath it.
What Does a Rain Screen Involve?
- A ventilated air gap behind the cladding
- Furring strips or specialized products creating the gap
- Openings at top and bottom allowing airflow and drainage
- A properly functioning water-resistive barrier behind the gap
Why Is a Rain Screen Important?
The ventilated gap a rain screen design creates allows water and moisture that penetrates behind the cladding to actively dry out through air circulation rather than remaining trapped, significantly reducing the risk of hidden rot and moisture damage compared to cladding installed in direct, tight contact with the wall assembly. This improved drying capability has driven increasing adoption of rain screen principles, particularly in wetter climates.
While rain screen design adds some cost and complexity to a wall assembly compared to traditional direct-applied cladding, this investment often pays off through significantly improved long-term durability, particularly for wood and fiber cement siding in climates prone to persistent wind-driven rain.
Rain Screen vs. Rainscreen Cladding
Rain screen describes the overall design principle and ventilated wall system. Rainscreen cladding specifically refers to exterior siding products manufactured or installed specifically to work within this ventilated system, often incorporating built-in spacing features.