Adam took an amazing video of a long, vertical concrete cold joint in a foundation corner that was leaking like crazy. Why does something like that happen and how in the world can you fix something like that? The Crack Daddy explains.
Narrator: It's time once again for the crackman podcast, hosted by A1 Foundation Crack Repair. I'm Darren Kincaid, and I'm here with the crack daddy himself, Adam Tracy. Adam has 20 years of experience in the construction industry and as a civil engineer is A1 Foundation's resident engineer on staff, solving a plethora of unique foundation problems every day. This podcast provides expert basement waterproofing, concrete repair, and preventative maintenance tips for homeowners and businesses. A1 Foundation's valuable insight will help avert the disaster of a flooded basement, health problems that are water infiltration, and protect your biggest investment, your home. The topic of today's podcast: Weak links in your foundation, understanding concrete cold joints.
Narrator: So Adam, you sent an amazing video of a long vertical concrete cold joint in a foundation corner that was leaking like crazy. What causes something like that to happen, and how in the world can you fix something like that?
Adam: Yeah, this one was a pretty good video to see because it really displays how impactful these joints can be on a waterproofing issue in a foundation.
Most of these joints that we're dealing with are additions that were put onto the house after the original construction. In this particular case, it was a house that had a nice 20-by-20 addition built onto the back, increasing the square footage of the home. To provide access into this new area, they essentially butted the old foundation up against the new foundation and performed a new concrete pour.
There are techniques used to fortify that connection so it’s not simply concrete against concrete in a straight line. Typically, contractors will dowel the connection by driving rebar through both sections to tie them together. In some cases, they’ll also install a gasket between the two sections to improve waterproofing.
I’m not exactly sure what methods were used here because we weren’t present during construction, and there weren’t any detailed plans available for us to review. However, the evidence was clear—this joint was leaking very easily, even during relatively light rainfall.
Some water issues can be reduced through exterior improvements such as installing gutters, rerouting downspouts, or improving the grading around the home. But in this case, the leak was occurring so deep below grade that simple regrading wasn’t going to solve the problem.
Most likely, the seam had been exposed during winter freeze-thaw cycles. Repeated freezing and thawing can gradually open up a small gap in the joint. Once that gap forms, water can enter very easily.
The good news is that you don’t have to dig up the yard and destroy all the landscaping or construction work surrounding the foundation. These joints can usually be repaired from the inside.
Typically, we drill into the foundation wall so that we intersect the cold joint between the inside and outside surfaces. We then install mechanical injection ports and connect them to an electric pump. Through those ports, we inject a closed-cell polymer resin material.
That resin fills the entire gap—from the inside to the outside and from the top of the joint to the bottom—effectively sealing it. Because the material expands and fills the void, we can waterproof the joint from the inside out without ever excavating the exterior side of the foundation.
Repairs like this are almost always easy to warranty, provided there isn’t any major structural movement. In this particular case, there was no significant structural issue, so it was a straightforward, warrantable repair.
Before the repair, the homeowners had been dealing with the problem for so long that they built a small containment box around the leaking corner and kept a sump pump there to remove the water whenever it entered. Every rainstorm was a concern.
Now they don’t have to worry about water coming into the basement anymore. The repair is fully warrantied, and the installation itself was quick and easy. The crew was in and out in less than two hours.
If you have a similar issue—or if you're planning a foundation addition—keep in mind that cold joints are common weak points where water can enter. Addressing the problem early, before finishing a basement, is extremely important.
If you wait until after the basement is finished, you may end up dealing with drywall repairs, insulation replacement, painting, and other restoration work. Taking care of the issue beforehand provides long-term peace of mind and protects your investment.
So, a cold joint is generally an easy problem to fix, it’s usually warrantable, and it can be repaired without major excavation.
Narrator: Well, thanks, Adam, for explaining how concrete cold joints can become the weak link in a foundation and how they can be repaired when they start to leak.
Narrator: If you have a basement water problem and think you need a professional, or if you'd like more information on foundation crack repair and basement waterproofing topics, please visit A1 Foundation Crack Repair.com or call Adam at (866) 929-3171. Or you can email Adam at info@A1FoundationCrackRepair.com. Thanks for listening and keep that basement dry.