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Polyurethane Crack Injection

Polyurethane Foundation Crack Repair

Foundation cracks allow water to penetrate basement walls, leading to leaks and moisture
damage. A polyurethane injection is a proven method for sealing non-structural cracks permanently.

Our Process

How Polyurethane Crack Injection Works

Polyurethane crack injection is a proven method for permanently sealing leaking foundation cracks from the inside. The process stops water at the source by filling the entire crack — from the interior wall surface all the way through to the exterior soil.

Clean & Prepare the Wall

We begin by thoroughly cleaning the foundation wall around the crack. This removes dust, debris, and residue to ensure proper bonding of repair materials. Proper surface preparation is critical for a long-lasting repair.

Install Injection Ports

Injection ports are placed directly over the crack at measured intervals. These ports allow controlled delivery of the polyurethane material deep into the wall. The ports are securely bonded to the concrete using a high-strength epoxy.

Seal the Crack Surface

Once ports are set, the visible portion of the crack is sealed with epoxy. This surface seal prevents material from escaping during injection, allows pressure to build inside the crack, ensuring the polyurethane fills it completely.

Inject Polyurethane Material

Polyurethane is injected through the ports starting at the lowest point of the crack and working upward. As the material enters the crack, it reacts with moisture and expands, traveling through the full thickness of the foundation wall. The expanding polyurethane fills internal voids, hairline fissures, and even small gaps in the surrounding soil outside the wall, creating a flexible, watertight seal.

Permanent Waterproof Seal

Once cured, the polyurethane remains flexible, allowing it to move slightly with natural foundation expansion and contraction. This flexibility helps maintain a long-term waterproof seal and prevents the crack from leaking again.

Why Polyurethane Injection Is Effective

Cracked Concrete Floor Surface

Protect What Matters Most

From basement leaks to yard grading and drainage, Schmitt Waterproofing offers trusted, cost-effective solutions that keep your home dry, safe, and protected for years to come. Let our experienced team help you avoid costly repairs – starting with a free, no-pressure assessment.

When Polyurethane Injection Is the Right Solution

Polyurethane injection is ideal for non-structural cracks that allow water intrusion, including vertical and diagonal foundation cracks. During your inspection, we determine whether injection alone is appropriate or if additional reinforcement is recommended.

Benefits of Polyurethane Crack Repair

When Polyurethane Injection Is Recommended

common questions

Frequently Asked Questions

What is polyurethane crack injection?

Polyurethane crack injection is a method of sealing leaking foundation cracks from the inside. The polyurethane expands to fill the full thickness of the wall, creating a flexible, watertight seal that stops water at the source.

Which types of cracks can be repaired with polyurethane injection?

Polyurethane injection is ideal for non-structural cracks, including vertical, diagonal, shrinkage, or settlement cracks that allow water to seep into your basement. It is perfect for actively leaking cracks.

Can polyurethane injection be used around sewer or water line penetrations?

Yes. Polyurethane injection can be used to seal water intrusion around sewer lines, water lines, and other pipe penetrations where they pass through the foundation wall. The expanding material fills voids and gaps around the pipe, creating a watertight seal that helps stop leaks without disturbing the plumbing or requiring exterior excavation.

How long does the polyurethane crack repair last?

Once cured, the polyurethane remains flexible and durable, moving with natural foundation expansion and contraction. This flexibility ensures a long-lasting waterproof seal that prevents leaks from returning.

Does polyurethane injection disrupt my home during installation?

No. The process is minimally invasive and completed from inside the basement. Injection ports are used to deliver the material precisely, keeping disruption to a minimum and protecting your finished spaces.

Can polyurethane injection fix leaking honeycomb areas in poured concrete walls?

Yes. Honeycomb voids in poured concrete walls can allow water to penetrate through porous or poorly consolidated concrete. Polyurethane injection fills these voids internally, sealing the pathways water follows and restoring the wall’s resistance to moisture intrusion without removing or rebuilding the concrete.