The Cost and Process of Crack Injection

This article about crack injection was shared with ECP from our very own Sam Rathbun, one of our leading waterproofing experts. Check back in the future for more articles from Sam and stay in the know on waterproofing problems and solutions.

Walking downstairs and noticing you have water seeping in through a crack in your wall is an awful feeling. Fear not though, it’s not the end of the world. Many cracks can be injected and sealed with a polyurethane foam.
Cost Depends on Size and Length of Crack
Crack injection is a fast repair and the cost is minimal. The cost is usually only a few hundred dollars depending on the size and length of the crack.
The national average cost for crack injection is $4,500, while most projects range from $2,300 to $6,700. Minor cracks may only cost a few hundred dollars, but the larger the crack, the more expensive the repair.
Polyurethane Foam an Ideal Solution
Often, foundation wall cracks are the path water takes when your basement floods. Polyurethane foam can seal cracks to eliminate water and air leaks.
Polyurethane will expand up to 20 times its original volume, sealing shut cracks. It is used to “weld” cracked concrete back together and restore the structural integrity of the cracked concrete.

Polyurethane foam injection is ideal for filling wider cracks and cracks that may exhibit signs of settling or movement from changing seasons or soil pressures.
It also works great for filling voids or sealing leaks around pipe penetrations. Filling the cracks reduces humidity and water vapor.
Polyurethane injections permanently repair foundation cracks. The application can be done from inside your basement.
The Process of Injecting a Crack in Your Basement Wall
- First you will apply the ports over the crack, it is how the polyurethane is transferred into the crack. They are placed approximately every 10 inches starting at the bottom of the crack working your way up.
- Next you will apply a “surface seal” to the wall. Most “surface seals” or “epoxy pastes” will set up in 30 minutes (hence the quick repair time).
- Once that has set up and cured, you will then inject the polyurethane into the wall. Starting at the lowest port on the crack and leaving all ports open, inject the polyurethane until it starts oozing out of the port above it. Once it starts oozing out, plug the port you are on and move up to the next one.
- Repeat this process until you have fully filled your crack.
- After the polyurethane has set up for around 24-48 hours you can knock off the ports with a hammer.
When NOT to use Crack Injection

NEVER let someone tell you that it is a promising idea to inject your crack if you have a block wall. Because the blocks are hollow there is no way to ensure that the polyurethane will set up where it needs to be.
There are other ways to seal cracks if you have a block wall and unfortunately, the best way is the most expensive way, and that is from the outside of the foundation.
Epoxy Injection vs. Polyurethane Foam Injection
Unless you are stabilizing your foundation with piers, do not inject the crack with a structural epoxy resin.
Structural epoxy resin is what it sounds like, it is used in conjunction with structural repairs. It is a brittle epoxy designed not to shift or move.
A polyurethane, on the other hand, will set up with a foam-like property. This is designed to bend and move with the crack.
If your house starts to settle a little more after you inject the wall, the foam will shift with the crack preventing unwanted water from intruding into your home.
Trust the Expertise of ECP Polyurethane Crack Injection
When it comes to filling basement wall cracks, trust the expertise of Earth Contact Products. ECP Polyurethane is an innovative blend of hydrophobic/hydrophilic polyurethane.
If you are looking for a ECP Partner Contractor in your area that offers crack injection, or any other type of waterproofing services, get connected with My Foundation Repairs by ECP.