Exterior Waterproofing prevents water intrusion into a basement. In order for a basement to be completely waterproof, it needs to have protection from subsurface water for all of the below grade walls. All of this protection must span from grade level down to a depth deeper than the basement floor. Lindsley Waterproofing uses state-of-the-art waterproofing materials—usually a 56-mil, pliable, rubber-like membrane to prevent wall penetration of water. Successfully blocking the sub-surface water from basement walls is not enough. We can’t just ‘wish’ the water away. We must provide a means of getting rid of the water that has been blocked by the waterproofing materials. Otherwise water would build up outside the foundation walls. Water doesn’t stack very well so it usually finds its way to the area under the basement floor and then rises from under the floor as it tries to ‘seek it’s own level’. Disastrous floods can, and very often do, occur without a single drop of water penetrating the basement walls. Waterproofing without drainage is destined to fail. You’d be better off having good drainage and no waterproofing!!! (A good roof isn’t even close to being waterproof but since it drains so well, there’s not a problem.) Basement drainage is much more difficult—it has to be deeper than the basement floor which is sometimes very deep in the ground.

There are two methods of getting rid of the water that waterproofing has blocked from the walls—installing a gravity drain or installing a pump system. A gravity drain is a downhill pipe sloped away from the house. It’s often referred to as a ‘tail line’. A gravity drain is the preferred method but there must be a destination for this pipe, or pipes, well below the basement level to which the water can flow. If there is no such destination on the property, the second method of water disposal is unavoidable—a pump system must then be used. Sometimes a pump system is opted for because it costs less and is easier to install.

Exterior Waterproofing & drainage is by far the best protection for a basement. It’s used almost exclusively when houses are being built. However, in ‘retrofit’ situations—not-so-new houses with established landscaping, connected utilities, air conditioners, patios, decks, additions, garages, etc., Exterior Waterproofing can be at best impractical—if not close to impossible. 

For a less expensive approach to correcting a flooding or leaky basement, see the section Interior De-Watering. 

For more information and help determining if Exterior Waterproofing is best for your basement, please contact us to schedule a FREE inspection and consultation.