Whether you’re building a new home or renovating one, it’s important that you understand how cove joints affect your foundation. Don’t worry if you’ve never heard about it. Here, we are going to cover a great deal about cove joints. Read on to learn more about them and what you can do to protect your foundation.
What Is a Cove Joint?
A cove joint is a plane of weakness at the intersection of the foundation wall and the basement floor when there’s a delay in the concrete pours. This happens when the first batch of concrete sets before the subsequent batch is poured, resulting in a discontinuity in your slab, which can lead to poor bonding.
During home construction, holes are dug in the ground and concrete footings poured before a block or poured foundation is raised and the basement floor created. Because of the preparation and concrete mixing that goes on, it’s common for some time to pass before the next layer of concrete is poured. Often, the first layer will have solidified before the subsequent pours. The time lag between the steps creates a cove joint between these three parts of the foundation.
Each layer has different chemicals, which shrink and swell at different times. Over time, the bond between the two layers may weaken and this creates a zone of weakness. If you suspect this is what’s happening, ask your foundation contractor to perform an inspection. They will locate the position of the cove joint and tell you whether it is causing moisture problems in your basement already or will in the near future.
Problems Associated with Cove Joints
The cove joint can become a thorn in the flesh during spring when precipitation is high. Because the two layers of concrete fail to bond, a weak plane will form, and this will impact the performance of your foundation. The resulting problems can range from mild to severe and may include:
- Weak concrete slab: True, concrete is strong, but it can become weak when a cove joint forms between its layers and water gets in. The freeze-thaw cycle in cold weather exerts significant stress on the concrete, and this can trigger wall cracks.
- Concrete becomes unsightly: A cove joint can also create a visually appealing discontinuity in your concrete. These are called cold joint lines. They appear when layers poured at different times start to harden.
- Nasty leaks: When wet concrete is poured onto an already dry slab, the fresh batch of concrete won’t bond with the existing layer. A void will form between the two layers and this gap will allow water to pass through.
Fixing Cove Joints in Concrete
It’s possible to repair cove joints in your foundation. One common way of doing this is applying watertight sealants on the planes of weakness. The sealants will prevent water from seeping through. Another thing contractors do is install rebar into the first layer of concrete before the next one is poured. What these do is tie both layers and increase the tensile strength of the joints.
We also recommend that you install interior drains. This will address seepage via the joint or through cracks on the floor. Our waterproofing experts will open the floor along your foundation wall perimeter and then lay down a perforated drainage pipe that is surrounded by washed gravel. Once in place, this system will collect water and empty it into your sump pump.
Why Should Cove Joints be Fixed?
Repairing floors with cove joints is the key to preventing water infiltration. With water out of the way, you won’t experience mold, mildew, or dampness.
If you want to preserve your home’s structural integrity, you should have the cove joints repaired as well. This won’t just boost your home’s value. It will also prevent harmful radon gas from getting into your home, and it will make it more difficult for pests and vermin to get inside as well.
Cove joints can stay inactive for many years. The only time they can cause problems is when they form dry joints that allow water to percolate through to your foundation walls. You can avoid water issues and protect your basement by scheduling a foundation repair inspection today. We’ll check the condition of the layers and recommend a fix to the cove joint problem.
If you suspect that there’s a cove joint in your basement, contact the experts at Complete Basement Systems for a free inspection. We’ll check your basement and tell you the extent of the problem then recommend a fix.