Foundation Crack Repair Methods
Poured concrete foundations can crack for several reasons, and we recently shared an article outlining these causes. In this post, we will explore the various crack repair options available, highlighting the benefits and drawbacks of each method.
Before diving into the specifics of repair techniques, it’s essential to emphasize that foundation crack repairs should be handled by a professional basement waterproofing company—no exceptions. Handymen and plumbers typically lack the necessary qualifications for these jobs. Conversely, waterproofers are not suited for tasks like hanging drywall or installing water heaters; it all hinges on the company's experience and expertise standing behind the repair.
Cracks in foundations can be sealed from either the interior or exterior. When performed correctly, both methods can be equally effective. If obstacles like decks or patios exist, or if your basement remains unfinished, sealing from the inside is more common. Conversely, if drywall or paneling is present, or if a furnace obstructs access, the exterior sealing method may be preferred.
Interior foundation crack repair has evolved significantly from the old method of "chipping it out and patching it." This involved using a rotary chipping hammer to create a V-shaped groove a few inches deep along the crack and patching it with hydraulic cement. Unfortunately, this method often didn’t endure well since it didn't fill the crack entirely to the outer soil, and hydraulic cement lacks the strength and durability needed.
Now, crack injection is the favored technique for interior foundation repairs. You may have heard about "epoxy injection" or "urethane injection." This process involves sealing the crack's inside face with an epoxy paste and injecting a resin (epoxy or urethane) that fills the entire crack to the external soil. We typically favor urethanes due to their flexibility and their effectiveness for waterproofing, whereas epoxy is better suited to structural concerns.
Externally, some homeowners still believe that the best method for fixing foundation wall cracks is from the outside. This mindset is often held by those from an older generation, before crack injection gained popularity. Repairing from the exterior remains a sound approach, especially when compared to a hydraulic cement patch.
To effectively seal a crack from the exterior, the adjoining earth must be excavated to expose the crack entirely from the top of the wall down to the footing. While some companies might simply dig a large hole, we prefer a less disruptive method using a post hole digger, typically creating a hole about 8 to 12 inches in diameter.
This method minimizes disruption to your landscaping, as there is no need for extensive excavation. After fully exposing the crack from top to bottom, we fill the hole with granular clay, forming an impermeable water barrier that prevents further moisture intrusion.