Two distinct Sika chemistries handle the full range of concrete crack conditions. Polyurethane expands on water contact, stopping active leaks in real time. Epoxy bonds dormant cracks to monolithic strength for permanent structural restoration. We diagnose the crack first, then inject the right Sika product to full depth. No guesswork, no failed repairs.
Concrete cracks fall into two categories: active (water is moving through them now) and dormant (dry, stable, not leaking). Trying to repair an active leak with epoxy fails because water displaces the epoxy before it can bond. Trying to repair a structural crack with polyurethane wastes the material because polyurethane is not designed for load-bearing restoration.
Sika polyurethane reacts with moisture and expands to fill the crack, creating a waterproof seal. Sika epoxy hardens to monolithic strength, restoring the two sides of the crack as if they were never separated. We assess each crack for activity, moisture, and structural role, then specify the matched Sika product.
Once the chemistry is chosen, port placement and injection pressure are engineered per Sika's technical specs. See our foundation crack repair work, and coordinate with Sika waterproofing for broader moisture control strategies.
Recent work
The injection sequence
How Sika Crack Injection Gets Done
Assess the crack condition
We examine the crack for signs of active water movement, measure depth and width, and determine whether it carries structural load. This assessment drives the chemistry choice.
Prepare and port the crack
The crack surface is cleaned and sealed with paste between engineered port locations. Ports are installed at spacing determined by crack geometry and Sika product flow specs.
Inject under controlled pressure
Sika polyurethane or epoxy is pumped through each port in sequence at the pressure needed to reach full depth. The material fills the crack from bottom to top, displacing air and water.
Cure, finish, and verify
The injected material cures (polyurethane in hours, epoxy in days). Ports are removed, the surface is sealed, and we verify full fill before the job is complete.
For active leaks
Polyurethane Injection Stops Water Now
When a basement wall or foundation slab is actively leaking, epoxy cannot work because water prevents the epoxy from bonding. Sika polyurethane is formulated to react with water, expanding as it cures and creating a waterproof seal inside the crack. The water itself triggers the reaction, so the repair works even in wet conditions.
Polyurethane injection is a one-visit repair for most residential leaks. The material cures fast, and the leak typically stops during injection. See our basement waterproofing services for broader moisture control, and check Sika waterproofing systems for exterior or interior membrane options.
Polyurethane vs epoxy, active leaks, port spacing and structural restoration.
Polyurethane for active wet cracks (it reacts with water to expand and bond), epoxy for dormant dry cracks that need structural restoration (it bonds the crack sides permanently). The wrong chemistry fails immediately.
Yes, polyurethane is specifically designed for this. The water in the crack triggers the polyurethane reaction, the material expands to fill the crack, and the leak stops.
Yes, with epoxy. Properly injected epoxy restores the two sides of the crack to monolithic strength. The crack itself becomes structurally stronger than the surrounding concrete in many cases.
Based on crack width, depth, and the chosen chemistry's flow characteristics. Sika specifies port spacing per product; we follow the spec so material reaches full-depth without gaps.
Most residential crack injections are a single-visit job, a few hours from port install through cure. Large structural projects with many cracks stretch over days. The schedule is in the quote.
Polyurethane injection on an actively leaking basement crack. Water stopped during injection, dry for two years since. The right chemistry made the difference.
Q. Y5
Property Owner, Gatineau
★★★★★
Epoxy injection for structural restoration on a foundation crack. Test cores after cure showed the crack zone stronger than surrounding concrete. Real structural repair.
Y. Y5
Engineer, Ottawa
★★★★★
Multiple cracks across a structure, each classified properly and injected with the right chemistry. The discipline of product-per-crack-condition is rare and showed in the result.
Z. Y5
GC, Barrhaven
★★★★★
They diagnosed an injection that another contractor had failed on. Used the right Sika polyurethane this time; held through three winters. Crack chemistry matters.
X. Y5
Builder, Nepean
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Describe the crack (active or dormant, wet or dry, structural or cosmetic), and we will diagnose, specify the matched Sika product, and send a written quote.
