What Is a Rainscreen?

As we all know, water trapped in a building’s structure will quickly lead to far worse problems than the original leak. A rainscreen is meant to stop water from coming near the edifice in the first place. Also called a “drain wall,” a rainscreen is essentially a secondary wall with a gap between itself and the primary exterior wall of a structure.

Rainscreens are made of light material that stands up well to moisture, mildew, and rot.

Rainscreens serve two main functions:

A Sacrificial Barrier

A rainscreen is the first line of defence against the elements and protects the building envelope against wind, rain, and UV rays. Most water that hits the rainscreen will bead off on the outer surface, but there is a second line of defence for any moisture that finds its way behind the screen.

A Water Drainage System

Water that makes it into the cavity between the rainscreen and the structure will be facilitated downward and out. A rainscreen needs to sit far enough off the wall, or else capillary action would invite water into the gap to linger and cause damage. This cavity is the crucial feature in a rainscreen; it not only stops water from collecting but also provides enough ventilation to dry out between rainy days.

A Good Idea!

Damage to the primary exterior wall can cost thousands of dollars, cause further moisture problems within the interior space, and endanger the health of the occupants. A rainscreen can mitigate these risks. Compared to the alternatives, the relatively low cost of a rainscreen is a worthwhile investment, and it is absolutely a good idea to consider having one installed.

Westerly Restoration provides building envelope integrity inspections and restoration in Surrey, BC and the entire Greater Vancouver area. If you have any questions about this article or would like to talk to us about building envelopes or restoration, please call us at (778) 881-2877 or use the convenient form on our Contact page.