If you’ve ever talked with a basement waterproofing contractor, he may have mentioned the term “cove joint.” You might have gotten carried away talking about something else, though, and forgotten to ask what a cove joint is. You also might not realize that your home’s cove joint is a specific area in your basement that’s especially vulnerable to water seepage.
Without going into too much detail, here’s an explanation of what cove joints are, and why they sometimes let water seep into a home’s basement.
What Cove Joints Are
Simply put, a home’s cove joint is the area between its foundation walls and the basement floor. The cove joint runs all the way around the perimeter of the basement. Think of it as the place where the floor meets the wall.
Why Cove Joints Sometimes Let Water Seep into Basements
Cove joints are particularly vulnerable to basement water seepage, mostly because of the way foundation walls and basement floors are constructed.
The first step in building a new home involves digging the large hole that will become the basement. Concrete footings with a channel running down the center are then poured around the perimeter of the hole. Ultimately, these footings will support the basement floor and the foundation walls. After the footings have completely set, dried and cured, the foundation walls are poured into the channel in the footings. The channel acts to “lock” the foundation walls into the footings, keeping the walls in position once all of the concrete has dried and cured.
Unfortunately, the concrete comprising the foundation doesn’t bond too well to the concrete of the footings. As a result, the foundation wall and the footings aren’t tightly sealed to each other. The gap between them is tiny, but when the adjacent ground is saturated, it’s large enough to let hydrostatic pressure force the groundwater into the basement.
For the same reasons, a tiny gap exists between the foundation wall and the basement floor (a concrete slab that has been poured on top of the footings). Hydrostatic pressure from saturated ground adjacent to the foundation wall can force water through this tiny gap (the cove joint) and into the basement.
If your cove joints is damp or wet, or if you see water seeping into your basement in this area, you’ll need to call an expert basement waterproofing company. The cove joint itself can’t be effectively sealed or patched, even with hydraulic cement. Installing a drain tile system is the only way that cove joint leakage can truly be corrected. An interior drain tile system is preferable because it will also relieve the hydrostatic pressure that’s being caused by saturated ground near the foundation.