How does polyurethane leak sealing work?
Concrete leaks that start as minor drips can often lead to major headaches. Contractors use Alchatek’s polyurethane leak seal process to fix this by injecting leak seal resins that react with water to expand and stop water infiltration. The two main polyurethane leak seal methods are crack injection, which targets and fills specific cracks head-on, and curtain grouting, which builds a wide “curtain” of sealed material behind the wall to catch hidden flows.
Application
The process begins with assessing the leak to select the ideal technique – crack injection for precise, linear repairs or curtain grouting for expansive protection:
- Step 1 – Inspection & Method Selection: The leak is examined to identify its pattern. Crack injection is chosen for simple, visible leaks (where resin is directed straight into the crack), while curtain grouting is used for widespread, complex or gushing leaks (creating a broad resin barrier in the soil behind the wall).
- Step 2 – Access Preparation: Small holes are strategically drilled – angled to intersect the crack precisely for injection, or arranged in a grid to distribute resin evenly for curtain grouting – then flushed to ensure clear pathways.
- Step 3 – Resin Injection: Polyurethane resin is pumped in at a controlled rate; it travels along moisture trails, expands to fill gaps and voids, and rapidly solidifies, forming either a targeted seal in a single crack or an integrated barrier with surrounding soil behind the wall.
- Step 4 – Completion & Verification: The entry points are sealed, allowing 30-60 minutes for full curing.
For complex leaks involving both surface and subsurface issues, contractors sometimes use the curtain grouting first for foundational blocking, followed by crack injection for refinement.
Benefits
- Faster and Cheaper: These methods speed up repairs and cut costs by 50-70% compared to removing and replacing concrete.
- Durable and Reliable: Polyurethane leak repairs hold up well in tough conditions, remaining flexible and waterproof despite dirt, moisture, or slight shifts.
- Where It Works Best: Crack injection is ideal for simple, single cracks. Curtain grouting is best for multiple cracks or gushing leaks. Combine them for full protection in complex cases.
