A rainscreen is a moisture management technique for controlling rain entry in an exterior wall that involves locating a pressure-moderated air space immediately behind exterior cladding in addition to employing a water resistive barrier.

The air space that is created by the rainscreen between the back of the cladding and the face of the water resistive barrier is designed to reduce the forces that draw water into the assembly. Water that does reach the back of the cladding is then permitted to drain from the wall assembly via the space created by the rainscreen. In addition to the drainage capabilities, a rainscreen system also helps accelerate the drying of moisture-laden air (vapor) that accumulates in the interior wall assembly by moving air in a convective fashion throughout the cavity.