What Is Epoxy Injection for Concrete Repair?

All concrete cracks, whether it’s a slab foundation, driveway, patio, or retaining wall. If you’re dealing with cracks in your concrete, the good news is there are ways to fill the cracks — even if they’re structural — to restore your concrete’s safety and appearance.

There are numerous reasons as to why concrete may crack over time. Let’s take a look at a few:
Shrinkage: As the excess water evaporates and the concrete hardens, it shrinks somewhat. From time to time, contractors may add too much water into the mix. This makes it easier to apply, but makes it more susceptible to cracking when it dries.
Weather: Extreme temperatures and sudden changes in temperature can cause concrete to cure poorly, which can lead to cracking down the line
Improperly placed relief joints: Relief joints are placed when laying concrete to make sure the slabs are evenly placed and relieve the pressure that can lead to cracking. If these are placed improperly, the concrete is further susceptible to developing cracks.
Freeze-thaw cycles: When the weather cools and heats up, it causes the moisture in the concrete to expand and contract. This causes cracks over time.

Cracks aren’t always aesthetic problems; they can also lead to a whole host of issues such as leaking, foundation instability, and more. With the use of an epoxy injection, the crack can be filled with an impervious seal, blocking air, chemicals, debris, and water with a material even stronger than the concrete itself. In situations such as this, water leaking through cracked concrete can lead to further erosion and corrosion of the reinforcing steel, so these cracks should never be ignored.

When preparing a crack for epoxy injection, it is important to first make sure the area is clean. This will allow for the concrete to properly adhere to the epoxy. At the least, the area should be brushed clean with a wire brush, and any grease, oil, or other potential contaminants need to be removed in order for the process to be successful. Follow the following steps, and the process of preparing your crack for an epoxy injection should go smoothly.

Remove any debris, dust, or water with the use of oil free compressed air
Any residue can be removed with the use of steam cleaning or high pressure washing
For the best results, the crack should be dry at the time of the procedure. If there is water seeping from the crack, locate the water flow’s source and shut it off.
Any water remaining in the crack can be removed with the use of compressed air.
Any coating or sealant that has been applied to the concrete must be removed so as to avoid the materials rising and causing a leak in the future

Epoxy injection can be a tricky business, and it’s always best left to the professionals, especially when it comes to structural cracks. The following are some common troubleshooting problems that may arise following the epoxy injection procedure.

More epoxy is required: It may be the case that the crack is branching off or expanding beneath the surface, so you should continue to fill the void. This may also be a sign that the epoxy is running straight through and out of the other side of the crack. If this is the case, and the crack runs completely through and out of the other side and is unable to be sealed, then an epoxy injection for crack repair may not be possible.

Less epoxy is required: If less epoxy is required than initially thought, this will mean one of two things. Either the epoxy is not penetrating the crack properly before moving on to the next port, or the crack is simply shallower than was initially believed. An injection of a lower viscosity epoxy to some ports will show if the crack will take more epoxy, or alternatively heat the epoxy between 80 and 100F to reduce its viscosity and allow it to reach smaller areas.

Epoxy is not showing up at the next port but is flowing into the crack: Quite often the crack can branch off or expand underneath the surface. In situations such as these, continue to inject the epoxy. If the crack completely penetrates through the concrete and out of the other side, and the back of the concrete cannot be sealed off, spending more time injecting the epoxy will not force the epoxy to the next port. In situations such as these, the epoxy will be running out of the back and epoxy injection repair will not be a suitable solution.