Two distinct Sika chemistries solve two distinct crack problems. Polyurethane expands on water contact, stopping active leaks in basement walls and foundation slabs. Epoxy bonds dormant cracks to restore structural integrity. We diagnose which condition you have, select the right Sika product, and inject to full depth. No guesswork.
A crack is not just a crack. The same injection material cannot solve both an active leak and a structural failure. Polyurethane is triggered by water; it expands and fills the void, bonding to wet surfaces. Epoxy is a structural adhesive; it hardens to monolithic strength but requires a dry surface to cure properly. Injecting epoxy into a wet crack wastes the material and fails the repair. Injecting polyurethane for structural restoration leaves the crack sides unbound.
Our first step is always diagnosis. We examine the crack for signs of water movement, measure its width and depth, assess whether it is actively moving or stable, and determine its role in the structure. Only then do we select polyurethane or epoxy. This discipline is what separates a lasting repair from a failed one.
We determine whether the crack is wet or dry, active or dormant, and whether it carries structural load. This assessment drives the chemistry choice.
Install injection ports
Ports are positioned along the crack at spacing specified by Sika for the chosen product. The crack surface is sealed with paste between ports to contain the injection material.
Pump Sika material
Polyurethane or epoxy is injected at controlled pressure through each port in sequence, filling the crack from bottom to top and ensuring no voids remain.
Cure and finish
The material cures (polyurethane fast, epoxy over several days). Ports are removed, the surface is sealed, and the repair is tested for completeness.
For active water
When Polyurethane Injection Stops the Leak
Basement walls and foundation slabs that are currently leaking cannot be repaired with epoxy. The water present in the crack prevents epoxy from bonding. Polyurethane is engineered for this exact scenario. The water triggers the polyurethane to expand and harden, filling the crack and sealing the leak. The reaction happens in minutes, and the repair holds through freeze-thaw cycles.
Pair polyurethane injection with Sika waterproofing when the broader wall or slab needs protection. Also consider basement concrete solutions for comprehensive water management.
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, Abbotsford
★★★★★
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, Chilliwack
★★★★★
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, Mission
★★★★★
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, Langley
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Describe the crack (wet or dry, active or dormant, structural or cosmetic) and we will recommend the matched Sika chemistry and provide a written estimate.
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Cost & Planning