Masonry Magazine February 2007 Page. 44
WATERPROOFING
WHAT WORKS
ABOVE,
DOESN'T
BELOW
Don't go below grade with an above-grade waterproofing approach. Special products are available to improve drainage and waterproofing for below-grade applications.
THE TWO IMPORTANT ASPECTS OF MOISTURE CONTROL BELOW GRADE ARE PROPER DRAINAGE AND A MOISTURE BARRIER OR MEMBRANE.
While membranes are a tool in the battle against water intrusion, the war is won with careful attention to drainage. A complete design approach is presented by Dale Kerr, general manager of GRC Building Consultants of Newmarket, Ontario, in a technical paper called "Drain and Dry Your Walls Fast." He speaks of the "4-D" strategy: deflection, drainage, drying and durability.
"Keeping rain off a wall (deflection) is the most obvious way to prevent water penetration-no water, no problem," he said. "Unfortunately, methods to accomplish that are not so obvious. While the use of overhangs and the protection afforded by adjacent buildings will help deflect some rain from the wall, there is no way to keep it all away. Walls must be designed to get wet.
By Tom Inglesby
38 Masonry February 2007 www.masoncontractors.org