Crack Injection
Foundation Crack Repair in Kansas City
A leaking crack in a poured concrete wall does not always mean a dug-up yard and a five-figure bill. When the crack is not structural, injection seals it from the inside in an afternoon. Here is how it works and, just as important, when it is not the right fix.
Most poured concrete foundations crack at some point. A thin vertical crack that weeps water after a hard rain is one of the most common calls we get, especially from newer homes in Lee's Summit, Olathe, Overland Park, and the Northland where poured walls are the norm. The good news is that a leaking, non-structural crack is usually one of the least expensive foundation problems to fix, and you do not need to touch the yard to do it.
What crack injection includes
We seal the crack from inside the basement by injecting a resin that fills it through the full thickness of the wall, front to back. For a leaking crack we generally use polyurethane, which foams and expands into every void and stays flexible so it moves with the wall instead of cracking again. When the goal is to restore strength to the concrete, we use a rigid epoxy that effectively welds the two sides back together. The service covers surface prep, setting the injection ports, the resin itself, and a clean finished repair.
The symptoms it solves
This is the fix for a visible crack in a poured wall that lets water in, a damp streak or mineral trail running down from a hairline crack, or a spot that drips only during heavy storms. If you see a single clean vertical or diagonal crack, often near a window well or where the wall steps, and water follows it inside, injection is very likely the answer.
Why cracks happen in Kansas City specifically
It comes back to the clay. Kansas City foundations sit in soil that swells when spring storms soak it and shrinks when summer drought bakes it. That constant push and pull works on a concrete wall year after year, and winter freeze-thaw wedges existing cracks a little wider each cycle. Even a well-built poured wall in a newer subdivision will develop a crack or two as the ground moves under it. The crack itself is often minor. The water it lets in is the real problem, and that is what injection stops.
When injection is not the right fix
This is where an honest contractor matters. Injection seals water out, but it does not add strength to a wall. If your wall is bowing inward, shearing along the base, or showing horizontal or stair-step cracking through block, you have a structural problem, and sealing the crack would only hide it. In those cases the right answer is bracing, wall anchors, carbon fiber straps, or in severe cases exterior excavation. We will tell you plainly which situation you are in. We would rather lose an easy injection job than sell you a fix that does not match the problem.
How the work is done
Injection is a clean, low-disruption repair. We clean the crack, mount injection ports along its length, seal the surface, and pump resin in from the bottom up until it travels the full depth of the wall and reaches the next port. Most single cracks are done in a couple of hours, and there is no digging and no heavy demolition. You can usually use the basement the same day.
Honest pricing
Crack injection commonly runs $400 to $1,000 per crack. Where you land depends on the length and width of the crack, how deep the wall is, and whether we are using polyurethane for a leak or epoxy for strength. Multiple cracks in one visit usually cost less per crack. You get a written price before we start, and if we look at the wall and see a structural issue instead of a simple leak, we will say so rather than injecting a crack that needs more.
Questions about crack injection
For a non-structural crack in a poured concrete wall, yes. Polyurethane fills the full depth of the crack and stays flexible, so it seals against water and moves a little with the wall instead of cracking again. We back the seal on the crack we inject.
Injection seals cracks, it does not add strength. If a wall is bowing inward, sliding at the base, or has stair-step cracking through block, that is a structural problem that needs bracing, anchors, or carbon fiber, not just a sealed crack. We tell you honestly which situation you have before we quote injection.
It depends on the crack. Polyurethane is the usual choice for a leaking crack because it stays flexible and seals against water even in a damp crack. Epoxy is rigid and is used when the goal is to weld the concrete back together for strength. We pick based on what your wall actually needs.
Got a crack that leaks every storm?
Book a free assessment and we will look at the crack, tell you straight whether it is a simple seal or something structural, and give you a written price.