Basement cracks appear in two locations: the floor slab and the interior wall face. Both need attention before freeze-thaw cycles or water pressure make them worse. We route and seal floor cracks with flexible material, inject interior wall cracks with polyurethane, and identify which cracks signal a deeper structural issue. Structural cracks get referred to our foundation repair team. Every visit includes a free assessment and a written quote.
Floor slab cracks and wall cracks behave differently because they form differently. A slab crack usually starts from shrinkage as the concrete cures or from settlement of the base underneath. These cracks run vertically and allow water to seep upward from below the slab. Wall cracks on the interior face typically come from structural movement or water pressure pushing from the outside, and they telegraph through the concrete thickness.
The repair method depends on the crack location. Floor cracks are routed open with a concrete saw to create a clean channel, then filled with a flexible sealant that can move slightly as the slab shifts with temperature. Interior wall cracks receive polyurethane injection through small ports drilled along the crack line, similar to how we handle foundation crack repair but applied from inside the basement.
Some cracks point to a bigger problem. Horizontal wall cracks often mean soil pressure is active, which belongs to foundation work rather than a basement-side patch. Cracks paired with active water leaks need interior waterproofing to address the root cause. We identify these during the assessment and recommend the right path forward.
Recent work
The repair sequence
How We Repair Basement Cracks Step by Step
Document and measure each crack
We photograph and measure every visible crack in the slab and along the interior wall surface, noting whether it is dry, weeping, or actively leaking, and classify it as shrinkage, settlement, or structural.
Route floor cracks to profile
Floor cracks are cut open with a concrete crack chaser to a clean V or square profile, the interior is blown clear of dust and loose material, and the channel is left dry and ready for sealant.
Seal or inject based on type
Floor cracks receive a flexible sealant pushed full-depth into the routed channel and finished flush; wall cracks get polyurethane injected through ports drilled into the concrete along the crack.
Why Basement Cracks Come Back Without Root Cause Work
Sealing a crack stops the leak at that point, but it does not fix what caused the crack to form. A slab crack above an old plumbing trench will reappear unless the base under the slab is rebuilt. An interior wall crack weeping water will continue to weep if the exterior drainage or grading is not corrected.
During the assessment, we identify what is driving each crack and explain the lasting fix. Sometimes that means a second visit to rebuild the base or install a new slab. Sometimes it means engaging the foundation repair side for structural work. Sometimes it means pairing the crack repair with interior waterproofing to manage water. The quote is honest about what the crack repair alone will and will not solve.
Slab vs wall cracks, sealing, injection, and when a crack signals something bigger.
Yes. Slab cracks get routed to a clean profile and sealed with a flexible material that handles small seasonal movement. Wall cracks on the inside face get polyurethane injected through ports along the crack. The repair matches the crack.
Not always. Some are dry hairlines that are cosmetic for now but worth sealing before water finds them. Others are already wet and need the cause addressed, drainage, an exterior crack, or a structural issue, alongside the crack repair itself.
Yes. Horizontal cracks usually mean soil pressure is pushing the wall and the right answer is structural; we refer those to foundation crack repair on the engineered side rather than injecting from inside.
It will stop the leak at that specific crack. If the basement is wet in multiple places, the root issue is usually drainage rather than the cracks themselves; the right answer is also interior waterproofing to address the cause.
Most basement crack visits are a few hours to a full day, depending on how many cracks and whether they are slab or wall. The slab repairs cure within hours; injected wall cracks cure overnight. The timeline is on the quote.
Homeowner reviews
What Detroit Homeowners Say About Basement Crack Repairs
Slab crack above an old plumbing trench got routed and sealed properly, and they said up front the base under it was the real cause. Honest call, the crack stayed sealed.
Q. B.
Detroit
★★★★★
Three slab cracks and one interior wall crack all in one visit. They classified each, repaired each the right way, and the basement is dry through the season.
X. K.
Warren
★★★★★
They flagged my horizontal wall crack as structural and referred it up rather than just injecting. Could have charged me and walked away. Glad they did the right thing.
Z. E.
Sterling Heights
★★★★★
Routed slab cracks instead of just smearing sealer on top like the last guy did. The repair has held through two springs of melt. Real method, real results.
F. V.
Ann Arbor
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Tell us about the cracks you see in the basement, whether they are in the floor slab or interior walls, and whether they are dry or actively leaking. We will assess them free and provide a written quote for any repair work.
