In residential construction most basements are simply sprayed with a tar based waterproofing agent or other similar coating. Contrary to popular belief, most basement leaks are not caused from lack of water proofing. Water that collects against foundation walls that does not drain properly, leads to most problems. This is called “hydrostatic pressure”.
Drainage board, that is often used on commercial structures, is a dimpled plastic membrane applied to the foundation wall. The drainage board allows any trapped moisture and hydrostatic pressure to be relieved by providing a space for the water to safely trickle down to the perimeter drain. This added step of protection is more important then the waterproofing itself.
When combined with a well-designed gutter system and properly graded lot, drainage board and standard waterproofing will keep a home dry, and reduce damp environments in lower levels. Excessively humid air can promote mold growth and air quality issues.
Drainage Board is an often overlooked step in the construction process.