Foundation Crack Repair (Polyurethane Injection)

If you have a leaking foundation crack in a poured concrete wall, polyurethane injection is one of the most
effective and economical repair methods — often performed from inside your basement without digging up your home.
Below we cover what matters most to homeowners: when it works, how it works, and what it looks like in real repairs.

Have photos? Text them to 289-366-1577 for faster guidance.

Why polyurethane injection is effective for foundation crack repair

Polyurethane injection (sometimes called urethane injection) is one of the most common and versatile injection methods
used to stop basement leaks and repair water entry paths in poured concrete foundation walls, ceiling slabs, and other concrete structures.
In demanding environments like tunnels and underground structures, cracks and fissures are often injected under high pressure
with polyurethane (also referred to as grout) — which is one reason this method performs under real-life conditions.

In some instances, epoxy crack injection is the preferred choice for certain crack conditions (including some settlement-related cracks). We’ll help confirm which approach makes sense for your specific situation.

How polyurethane crack injection works

Polyurethane injection involves the pressurized injection of activated polyurethane resin through injection packers hammered into drilled holes in poured concrete basement foundation walls. The injected resin travels through the thickness of the foundation wall (often approximately 8″). Within the crack, polyurethane expands and solidifies within the cavity, eliminating the water path and preventing leaks into your basement.

Note: Polyurethane can also be injected at a lower pressure using a process virtually identical to that used for epoxy crack injections.

What a polyurethane injection repair looks like (real examples)

Injected polyurethane oozing out of an injected foundation crack

Polyurethane crack injection in progress

Expanded polyurethane foam visible on the exterior of a foundation wall — Expanded polyurethane can travel through the foundation to the exterior, making excavation unnecessary in many crack cases

What polyurethane injection can repair

Common homeowner scenarios

Actively leaking cracks in poured concrete foundations;
Foundation crack repair for wet or damp basement walls;
Previously repaired cracks (internally and/or externally) that are leaking.
Note: an epoxy injection is not appropriate for repairing a failed crack injection.
Cracks full of mud or mineral deposits;
Leaking forming tie-rod holes;
Leaking forming snap rods;
Underground pipe penetrations for electrical conduits, gas lines, air conditioning lines and pipes;
Honeycombing;
Seams created by a cold pour.

Specialized / structural applications

Cracks caused by corroding reinforcing bars (typically in reinforced concrete slabs in underground parking garages);
Leaking underground structures in general (such as parking garage cracks and seams);
The bottom of swimming pools (when the underside is accessible);
Overhead concrete structures.

Wondering how much a crack injection costs?
Find out now!

Examples of problems repaired with polyurethane injection

If any of the images below match your situation, polyurethane injection is often a viable and cost-effective foundation leak repair method.

Visible water and staining at the bottom of a leaking foundation crack — Visible water and staining coming from a leaking crack in a poured concrete foundation

Leaking tie-rod hole in a poured concrete foundation — Leaking tie-rod hole – poured concrete foundation

Leaking around the electrical conduit feeding the main electrical panel — The conduit containing the electrical wiring bringing power to the electrical panel

Honeycombing and visible aggregate in a poured concrete foundation — Leaking honeycombing (visible aggregate) in poured concrete caused by voids/poor consolidation

Leaking I-beam pocket in a poured concrete foundation — Leaking I-beam pocket – poured concrete foundation

Leaking previously repaired foundation crack

Video: high pressure polyurethane crack injection repair

Watch how we repair a leaking foundation crack from inside using high pressure polyurethane injection.

<br />

Why polyurethane performs well for foundation crack sealing

Polyurethane injection works well across a range of leak conditions because properly selected polyurethane resins can:

Expand (helpful when filling unknown void size, such as honeycombing);
Follow the path of least resistance and fill gaps/voids encountered;
React well in the presence of water (useful for active leaks and hydrostatic pressure);
Remain flexible (helpful with thermal cycling and minor movement);
Set quickly (often essential where hydrostatic pressure is significant);
Be adjusted in viscosity to address conditions from hairline cracks to larger voids.

Note 1: Several technical factors determine whether a crack should be injected using
epoxy
or polyurethane. Our trained technicians can confirm which approach is best for your circumstances.

Note 2: Not all waterproofing contractors offer high pressure polyurethane injection repairs.
Successful injections require training, proper equipment, and high quality formulations — otherwise injections can fail.
In some cases, competitors call upon us to perform warranty repairs.

Want help identifying the right repair? Text photos to 289-366-1577 or visit
Request a Quote.