A rain-screen wall consists of all the essential elements of a drainage wall, which are: (i) exterior cladding, (ii) air space, (iii) water-resistant backup wall, (iv) flashing, and (v) weep holes. What is the most important additional element in a rain-screen wall that distinguishes it from a drainage wall?

Question

What will be an ideal response?

Answer 1

While the exterior cladding in a drainage wall contains no voids except the weep holes, a rain-screen wall contains purposely-introduced, additional voids in the exterior cladding. These additional voids ensure that the air pressure within the air space (behind the cladding) is the same as that on the outside face of the cladding.