Foundation Drainage That Keeps Water Off the Wall
Foundation drainage is the combined system that stops groundwater from building up against a foundation. It includes the perimeter drain at the footing, the damp-proofing or waterproofing on the wall itself, the surface grading that directs rain away from the building, and the sump or storm connection that carries collected water away. When a basement is wet, the cause is usually one of these — and the fix depends on which one has failed.
How water gets into a foundation
Water enters a foundation in three main ways: through the footing joint when the perimeter drain has failed, through cracks in the wall when exterior waterproofing has deteriorated, and over the top of the wall when surface water is not directed away. Each has a different fix, and the first step is identifying which one is actually happening on your property.
The components of a foundation drainage system
A complete system works in layers.
- Surface grading — the ground should slope away from the foundation for the first several feet
- Damp-proofing or waterproofing membrane on the exterior wall
- A drainage board or dimple membrane to break hydrostatic pressure against the wall
- The perimeter drain at footing level in clean gravel
- A sump pit and pump, or a gravity connection to the storm sewer
When to repair vs. when to replace
If the perimeter drain is intact but the wall waterproofing has failed, the fix may be a section excavation to re-waterproof the wall and install a drainage membrane. If the perimeter drain itself has failed, no amount of wall waterproofing will relieve the hydrostatic pressure at the footing, and the drain needs replacing. We inspect before recommending either.
Foundation Drainage — common questions
Request Drainage Service
Tell us what is happening and where. We will call you back the same business day to discuss the problem and arrange an inspection if needed.