Masonry Magazine December 2011 Page. 27
Subsection 9.27.2.3-1b of the "National Building Code of Canada 2005, Vol. 1
Subsection 9.27.2.3-1b of the "National Building Code of Canada 2005, Vol. 1 states: "The second plane (the drainage plane) of protection shall be designed and constructed to i) intercept all rain and snow that gets passed the first plane (the veneer) of protection and, ii) effectively dissipate any rain or snow to the exterior."
Real waterproofing involves real drainage
In his August 2010 article "Putting in Holes to Stop Leaks," Brett Newkirk wrote, "A wise Canadian once said, "It is amazing how many leaks you can stop by putting holes in a building." The holes referenced are weeps, but not just any weeps. Gone are the days of the "wicking" rope weep or the weep tube. If these old-style weeps worked at all, it was because some water leaked out of the moisture voids next to them and not through the weep itself. Many times, these antiquated weep devices weren't even placed at the lowest point in the wall. An effective weep must be placed at the lowest point in the wall (the bed joint of mortar). Weeps also need to be placed frequently to be effective. The channeled weeps in Figure 6 are placed 10 inches on center.
During the last 20 to 30 years, we have experienced myriad moisture-related problems in the building envelope. The increased use of rainscreen technology by designers has seen more than its share. Many reasons for moisture problems in the rainscreen building envelope exist. Some of the most frequent issues include: Tighter building envelopes increased mold and rot problem. Many modern materials created unintended moisture barriers. Increased insulation led to condensation problems.
View of entrapped moisture damage to materials in a rainscreen building envelope with no drainage.
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