How does ground water hurt walls

Dampness in walls above grade is not often caused by moisture rising from the ground. However, where soil drainage is inadequate and the foundation walls have not been waterproofed, a sufficient amount of moisture may be absorbed or drawn up into the walls to cause dampness to a height of 4 or 5 feet above ground level.

Conditions might be improved by regrading to divert surface water away from the walls.

In new construction, it is considered good practice to install through flashing consisting of an impervious material, such as sheet- metal or slate, which is inserted through the wall at a height of 5 to 10 inches above the ground as a barrier to prevent the rise of moisture.