Should you use epoxy or polyurethane to repair a foundation crack in your Westmont, IL home? Learn the difference between the two and which is best for your basement.
Foundation cracks are common in Westmont homes due to shifting soil, seasonal temperature changes, and water pressure. When it’s time to seal a crack, one of the biggest decisions is choosing the right material: epoxy or polyurethane.
Both are widely used for concrete crack repair, and while they may seem similar, they serve very different purposes. Picking the right one can make the difference between a quick fix—and a lasting solution.
In this article, we’ll explain the difference between epoxy and polyurethane, when each is used, and which one is best for your specific basement crack.
Epoxy is a rigid, high-strength resin used to bond cracked concrete back together. Once injected into a crack, epoxy cures into a hard, solid material that restores the original strength of the wall. It doesn’t flex or move after it sets.
Epoxy is often the go-to choice for serious cracks that have weakened the foundation wall. It’s designed to hold the concrete together under load, making it ideal when stability is a concern.
Polyurethane is a flexible, foam-like sealant that expands after injection. It’s designed to stop active water leaks by filling cracks and creating a watertight seal—even in wet conditions. Unlike epoxy, polyurethane doesn’t bond the concrete—it simply seals the space.
Because polyurethane remains slightly flexible after curing, it can handle minor movement caused by soil pressure or temperature swings—something Westmont homes experience year-round.
While both epoxy and polyurethane are commonly used for foundation crack repairs, they serve different purposes based on the condition of the crack and the goal of the repair.
Epoxy is known for its strength and is best used for structural repairs. It cures into a rigid, solid material that bonds tightly to concrete, making it ideal for dry cracks where restoring wall integrity is the primary goal. However, it requires a dry surface to adhere properly and does not flex once cured.
Polyurethane, on the other hand, is more flexible and expands after injection. It’s the preferred choice for sealing actively leaking or damp cracks. Unlike epoxy, it works well in wet conditions and creates a watertight seal—but it doesn’t provide structural reinforcement.
In short:
Each material has a specific role, and the right choice depends on the conditions of your foundation and the nature of the problem.
The best choice depends on the purpose of the repair and the condition of the crack:
In some cases, both materials are used—polyurethane to seal an active leak, followed by epoxy later for structural reinforcement.
These injection materials are most effective on poured concrete walls. If your Westmont home has cinder block or brick foundation walls, different repair methods—like carbon fiber straps, wall anchors, or interior drainage—may be required instead.
Block walls often leak due to pressure in the hollow cores, and injection isn’t effective in that type of construction.
At Accu-Dry, we’ve repaired hundreds of foundation cracks across Westmont and the surrounding areas. Our technicians are trained in both epoxy and polyurethane injection and understand when to use each material for the best result.
Every crack repair starts with a free inspection to determine the cause, behavior, and urgency of the issue. We don’t apply band-aid fixes. We use the method that will keep your foundation stable and your basement dry—for good.
Whether you’re dealing with a small surface crack or an active leak, choosing the right material matters. Don’t guess between epoxy and polyurethane—let an expert help you make the right call.
Contact Accu-Dry today for a free, no-pressure inspection. We’ll assess your foundation and recommend the best solution to protect your home in Westmont for years to come.
