What is a Cove Joint?

Waterproofing guru Howard Shachter, vice president of U.S. Waterproofing, defines what a cove joint is:

The cove joint is the spot where the concrete of the floor meets the concrete of the wall. This spot is sensitive as builders often pour the concrete for each of these pieces at different times during the construction process, leaving nothing more than what is essentially a sealed crack in the concrete where the floor meets the wall. It is often looked at when water is permeating into a house. With heavy or prolonged rains, groundwater along the foundation walls and underneath the basement floor can rise, allowing water to seep upward through this joint. This is commonly referred to as hydrostatic pressure.

Sealing the cove joint is usually not recommended since the pressure will build and move elsewhere. Instead, U.S. Waterproofing recommends installing a Drain Tile System, which is a perforated pipe embedded in washed stone installed beneath the level of the floor. The system can be installed from either the interior or exterior.

The Interior Drain Tile System is the most common basement waterproofing solution for this problem. The system collects the water beneath the floor and directs it to a sump pump, decreasing the upward pressure.

The Exterior Drain Tile System can also be used to address cove seepage. The main difference, however, is that the hydrostatic pressure is relieved from the outside, so walls will need to be excavated.