Masonry Magazine December 2011 Page. 22
Drainable
IS
Sustainable
Why the best waterproofing
system includes a drainage
plane system.
BY MARK A. JOHNSON AND
JOHN KOESTER
ART BY ADAM SKODA
MOST EXTERIOR SURFACES OF A VERTICAL WALL SYSTEM DO ALLOW
SOME MOISTURE TO PENETRATE MORE DEEPLY INTO THE EXTERIOR
BUILDING ENVELOPE. Why do building professionals allow this? Don't we
have adequate waterproofing systems? Of course we know, and of course we do,
but that isn't the "hole/whole" story.
The hole/whole story the more complete story is that some exterior building surfaces of the exterior building envelope are responsible for more than just moisture management. These responsibilities include aesthetics, structural support, signage support, mechanical support and protection (veneers acting as shields). In addition to all these responsibilities, they also have to manage moisture.
So, the hole/whole story is a little more complicated. As part of the process of moving forward, let's take a look at an example of a typical exterior wall (exterior building envelope). Obviously, many types of wall systems exist, but let's use this one (see Figure 2.) to simplify the discussion as much as possible.