Expansion joint injection and construction joints

Expansion joint injection and construction joint injections are technologies used to seal critical gaps in building structures. They are applied in areas where the original waterproofing systems have failed (e.g., in basements, tunnels, or parking garages). When performed correctly, this procedure effectively stops leaks and restores the structure’s full watertight integrity for the long term.

What are expansion joints and construction joints?

These are gaps in the structure of a building that are either intentionally designed or result from the concrete pouring process; due to their specific nature, they are most susceptible to water infiltration.

The main causes of leakages:

Aging or damage to sealing strips, construction errors during concrete pouring, contamination of joints, structural movement, and high groundwater pressure.

Classification of sealed elements based on their nature:

Depending on their function within the structure, we distinguish between static working joints (construction joints) and dynamic expansion joints (which allow the structure to move). Proper identification of the nature of the gap is a key factor in selecting the appropriate technology and the flexibility of the injection material.

Selection of grouting materials

In joint sealing technology, specialized, flexible sealants are used, selected based on the dynamics of the joint:

• Acrylic gels: Most commonly used for sealing active expansion joints and for curtain injection, due to their excellent penetration, flexibility, and resistance to moisture cycles.
• Polyurethane resins: Commonly used for quickly stopping severe water leaks (foaming formulations) and for providing a durable, flexible solution for sealing construction joints.