A Quick Guide to the Cross-Drill Injection Process

For many of our clients seeking crawl space repair in Highland Park, Naperville, and the greater Chicagoland area, the most-requested repair is a leak requiring immediate attention. Leaks often stem from cracks, some of which were already repaired (unsuccessfully) before. These are commonly known as “dirty cracks”, of which there are two types:
● A dirty crack that was repaired on the surface but wasn’t injected with sealant. Thus, the surface repair didn’t hold and the leak returned.
● A dirty crack that was injected with sealant, but the sealant failed – whether because not enough was used, it wasn’t applied correctly, or it was of an inferior variety
The first example can be repaired with sealant and surface application. But repairing the second type of dirty crack is a little trickier. That’s why ULB-DRY Waterproofing uses a system called “cross-drill injection” that works exceptionally well. We’re one of the only waterproofing companies using this technique, and we’ve employed it to great effect for many of our customers.
Cross-drill Injection
Cross-drill injection is the perfect solution for homeowners seeking crawl space encapsulation. Being so close to your home’s foundation, any leaks detected must be dealt with swiftly lest they create a bigger problem down the road. Here’s how cross-drill injection works:
● A set of 3/8th-inch holes are drilled within 4” – 6” of the crack. These holes are angled inwards in order to intersect the void at the halfway point.
● Small brass packers, each with a zerk end, are placed securely in each hole
● Once these packers are in place, the void is flushed with cool, clean water
● A one-part urethane grout is injected into the void with a high-pressure pump
● We don’t stop injecting until the urethane grout oozes out of the void, or the back-pressure reaches a certain point. Any material that oozes out is removed once it has hardened.
● With the void completely filled with urethane grout, and with all ejecta cleared away, the entire crack is coated with a flexible, two-part epoxy mastic (a natural bonding agent). The crack is 100% repaired, to the point where you’ll have a hard time believing it was ever there.
● At every step of the process, from preparation to repair to cleanup, health and eco-consciousness are top-of-mind. None of the materials we use are hazardous to the residents’ health or potentially damaging to the environment.
Cross-drill injection is a viable option for repairing a broad size-range of cracks – even ones as narrow as .002 inches. Outside of the waterproofing industry, this technique is used to repair cracks in bridges, dams, buildings, and various other concrete structures. In fact, no less a group than the U.S. Army Corps of Engineers has in their Engineer Manual a “how-to” page concerning cross-drill injection.
If you have a crack of any size that requires immediate repair, whether it’s in your crawl space, basement, or somewhere else, contact ULB-DRY Waterproofing today for a quote. We have offices in Villa Park, Lombard, and Chicago, and we serve the entire Chicagoland area.