Drainage Panels for a Foundation Wall

Foundation Drainage

• Water penetrating the foundation causes wet basements, mold, flooding and property damage. Eventually, the structure is undermined by water and the foundation can fail. The drainage system is critical for keeping the foundation dry. The system usually consists of a waterproofing membrane applied to the foundation wall to allow water to drain to the footings; a footing drain -- usually perforated pipe -- to guide water away from the foundation; and a sump pump or subsurface channel to discharge the water to a safe point.

Foundation Drains

• The underground drainage tile is laid on a washed gravel bed, sloped for water flow away from the foundation. The gravel acts as a filter to keep soil and sediment particles from entering the perforations of the drainage pipe and obstructing the flow. The gravel is spread on geotextile cloth to separate it from the soil beneath, or the pipe itself is wrapped in cloth. Despite the precautions, the pipe is subject to being clogged with soil particles from the gravel backfill.

Drainage Panels

• Foundation drainage panel systems are installed in areas with a high water table or hydrostatic pressure -- buildup of water in the soil. Engineered, prefabricated panels, or drainage boards, are applied to the foundation wall, which may or may not be treated with waterproofing. The panels can be solid board material with a porous structure, or a dimpled plastic grid, or geogrid -- a twisted, plastic wire grid. Some products have filter fabric or insulation added to the panels.

How Drainage Panels Work

• The porous boards let water drain vertically down to the foundation drain, and the dimpled polyethylene -- plastic -- sheets and geogrid leave an air space between the wall and the material that provides a pathway for water to drain downwards, reducing hydrostatic pressure against the wall. Certain products replace drain pipes by including a strip drain that connects to a pipe to convey water to the discharge point. Drainage panel types are chosen according to the site soil conditions.