Cracks in Concrete

5 Steps for Concrete Crack Injection

The job of repairing cracks in concrete is not a joyous one as it is very labour intensive while at the same time crucial that it is being completed by a professional.  When it comes to concrete crack injection in Edmonton on an industrial scale, there are five basic steps needing to be done and by understanding these steps, you will be on your way to appreciating what it takes to seal a water leak in concrete.

Here is some technical data that may help if you want to know the chemical and physical specifics of the process.


5 steps for Concrete Crack Injection in Edmonton:

  1. Drill holes:
    • The first step in the crack injection process is to drill holes in the concrete that intersect the existing crack. Typically, the holes are drilled at a angle of 45 degrees, intersecting the crack at the halfway point through the structure. Doing this will ensure that the polyurethane forced towards the front and back of the crack.


  1. Flush out the holes
    • The process of drilling concrete will obviously create a certain amount of dust. Neglecting to flush the dust out of the drill holes can result in the concrete dust being forced into the crack with the injection of the polyurethane resulting in a clog that may prevent the injection from reaching the areas that it needs to go. By putting a flexible hose all the way to the back of the hole, water can flush the dust from the back of the hole back to the entry point or surface of the concrete. Make sure to flush the drill holes until you can see clean water is flowing.


  1. Installation of injection port
    • The injection port is what seals the hole providing the injection pump a direct connection to the crack. There are a variety of ports that are suited for various types of Applications.
  • Place the selected port in the drilled hole so that the top of the sleeve is just below the concrete surface.
  • Tighten the port using a ratchet, socket or open-end wrench until firm and secure.
  • Injection ports are supplied with a one-way ball valve or check valve to ensure the polyurethane does not escape back out after injection.


  1. Flush the crack
    • Flushing the crack will ensure that the crack is wet enough to react with the injection material when it is introduced into the crack. Flushing the crack serves a number of purposes:
  • Cleans the crack of dirt and other debris to ensure that the polyurethane flows freely.
  • Gives an idea of how far and how easily the material will flow into the crack when you start injecting.
  • Helps to open up areas that the injection material may otherwise not flow. Water is thinner than polyurethane and will penetrate deeper and into tighter areas.
  • Ensures the material will have enough moisture to react with.


  1. Inject the Polyurethane
    • It is important to use the lowest pressure that will continuously feed the polyurethane into the crack. Gradually increase the pressure as necessary to ensure the material is flowing. Something to keep in mind is to keep injecting even if material begins to flow out of the crack. As long as more polyurethane is going in than is coming out, you are increasing your chances of a successful injection. Once the material isn’t moving further along the crack, it is time to move on to the next port.


If you follow these 5 steps you will be well on your way to repairing your concrete. 

For any advice related to concrete crack injection, contact Michael at Walser Contracting Ltd!


Walser Contracting Ltd.
Concrete Cutting & Coring Services
15C Alberta Ave, PO Box 3816,
Spruce Grove, AB T7X 3B1

Monday to Friday: 6:30am to 4:00

Call: 780-721-3405

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