Leak Seal for New Construction Defects Series - 3. Curtain Grouting

Curtain grouting is primarily employed to address multiple leaks at once. This technique originated in the 1960s. It was initially used to remedy water intrusion issues in sewer systems. Over time, its application expanded to a wide range of structures, driven by its efficacy in creating a barrier against water penetration. Curtain grouting involves injecting an expansive polyurethane grout through a wall or floor, into the soil on the other side. The grout then spreads out and expands, forming a 'curtain' that seals many leaks and cracks at once.

A Brief Overview of the Curtain Grouting Process

1. Drill injection holes in a diamond grid pattern.
2. Begin grout injection at the bottom of the wall.
3. Inject grout a little higher, so that any excess grout flows down over the previous injection area. This creates a lapping effect, like shingles on a roof.
4. Continue injection to the top of the wall.

Managing Multiple Leaks

Curtain grouting is particularly valuable in scenarios where multiple leaks are present or when the source of water intrusion is indeterminate. This method provides a comprehensive solution, sealing numerous potential entry points for water and thus is more efficient and cost-effective than attempting to address multiple leaks individually.

Hypothetical Examples

One notable application could involve an existing multi-story building with an underground parking garage, which has water intrusion issues. In another hypothetical example, a new modern high-rise building with below-grade levels planned could utilize curtain grouting during construction, resolving waterproofing concerns without needing extensive excavation or costly, long-term dewatering.

Curtain Grouting in a Nutshell

Curtain grouting is a technique that involves injecting an expansive polyurethane grout through a wall or floor and into the soil behind it. As the grout spreads out and hardens, it forms a "curtain" that seals multiple leaks and cracks at once. This barrier can prevent water from intruding into a structure that has existing issues or be installed proactively in new construction to waterproof below-grade spaces like underground garages. Curtain grouting is often a more efficient and cost-effective solution compared to addressing multiple leaks individually.

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