Aside from rain water, water vapor also needs to be vented out by the exterior commercial waterproofing system.
A drainage plane creates a pressure-filled space in wall cavities. This counters the pressure from outside the wall cavity, effectively driving water vapor out. This ensures that even minute quantities of water are removed from any free space in the wall cavities.
Despite the installation of the most appropriate exterior commercial waterproofing system, it is unavoidable that water may still penetrate the building’s barrier system. When there is moisture intrusion, it is not often easy to remove it and dry the area.
Since the walls are commonly the first to take the onslaught of water, they may remain wet for long periods of time. This leaves the walls vulnerable to rotting, rusting and possible growth of microbial organisms. The worst case is when the walls decay and compromise the building integrity.
To prevent moisture from being trapped and unable to leave the building, the exterior commercial waterproofing system must include a drainage plane system.
When rain water assaults the exterior walls, it enters through the highest point in the wall. The drainage plane is a pathway for water to flow through and exit to the lower areas of the wall.