Basement crack repair in 8 steps



Basement cracks can be a common problem for homeowners. They may be caused by foundation settling, water damage or other factors. They are not just unsightly, but can also cause issues like basement leaks, flooding and mold. Basement waterproofing protects against these issues. If you are a homeowner with a basement crack, it is important to repair it as soon as possible.

This article will discuss how to repair basement cracks in eight steps. It will provide information on the causes of basement floor and wall cracks, and how to fix them using different methods, such as epoxy injections and carbon-fiber strips for basement waterproofing.


How to fix cracks in concrete foundation

Before you get started, you want to assess where the crack is and what this can mean for your DIY project. There are different types of cracks. Basement cracks can form in two places: 

basement wall cracks and basement floor cracks. Whether you have a crack in a concrete wall or the concrete floor in the basement, the approach to basement crack repair is the same.

Wherever they are, it's important to know how to fix them. Let’s walk through the eight steps for DIY basement wall crack repair or basement floor crack repair.

Step 1. Gather the right supplies

When it comes to basement crack repair, having the right supplies on hand is essential. First, you'll need a good-quality repair kit. A liquid concrete repair kit will have all the necessary items to fix the crack, including an epoxy crack sealer, injection ports and a brush.

Another repair kit option includes a two-part epoxy sealer, caulk-type cartridges of repair compound and injection ports. Injection ports are small plastic nozzles that allow you to fill the inside of the crack with the epoxy sealer. You'll attach the ports to the wall, cover the crack's surface with the two-part epoxy sealer, then inject the crack with the repair compound.

There are two types of injection compounds available: epoxy and polyurethane. Epoxy is the preferred option for dry cracks in load-bearing foundation walls and slabs. Polyurethane is the better choice for damp or wet basement cracks. The application process is basically the same for both compounds.

Make sure you have plenty of rags or old towels on hand to clean up any messes. Gather a screwdriver, hammer, nails and a drill. You'll also want to have sandpaper, an electric sander or a multitool with a sanding attachment to make sure everything is flush and level when you finish. With the right supplies on hand, your basement crack repair will go smoothly.

Step 2. Prep the foundation wall

Whether you’re dealing with hairline cracks on the concrete floor or more substantial foundation wall cracks, you need to prep the area before you begin any work. Before beginning any repair method, it is important to ensure that the crack is dry. If the basement wall is damp, you can dry it with a hair dryer or by using a dehumidifier. Once the wall is dry, use a brush or vacuum to remove any dust, debris or loose concrete from the crack. This will help ensure that the epoxy adheres properly to the surface.

Step 3. Block out the injection ports

If you're using a liquid concrete repair kit to fix basement wall or floor cracks, you'll need to install injection ports. This will ensure that the epoxy injects into the crack and not on the surface of the wall. 

As mentioned, injection ports are small plastic nozzles that allow you to fill the inside of the crack with the epoxy sealer. You'll attach the ports to the wall, cover the crack's surface with the two-part epoxy sealer, then inject the crack with the repair compound. In this step, you need to tap 10d nails halfway into the crack in 12-inch intervals. Gently hammer 3-inch 10d finishing (headless) nails into the crack.

Step 4. Mix the epoxy sealer

To mix the epoxy sealer, first combine the two parts: the resin and hardener. You can do this in a plastic cup or bowl. Stir them together until they are fully combined, following the directions on your concrete crack repair kit.

Step 5. Attach the injection port

Slide the plastic injection ports over the nails you placed in step three. Remove the nails after you slide the injection ports over them. Leave enough of each nail's shaft exposed so about  half-inch to 1 inch protrudes past the port's nozzle, making it easy to grasp the extra length and remove the nail.

Step 6. Spread sealer along the crack

To spread the sealer along the crack, use a brush or a putty knife. Make sure you get the sealer into all the nooks and crannies of the crack. Smooth it out and make it as even as possible.

Step 7. Inject the epoxy into the crack

Once you've spread the sealer along the crack, it's time to inject the epoxy. Your kit should come with a crack injection tool, like a caulking gun. Foundation crack repair is best done with an injection gun, but you can also use a syringe. Follow the directions on your concrete crack repair kit. Inject the epoxy sealant slowly and evenly into the crack. You may need to do this in several stages, depending on the size of the crack.

Step 8. Seal up and cut away the injection ports

Once you've injected the epoxy sealant into the crack, seal up and cut away the injection ports. Use a caulking gun to apply a bead of epoxy around each port. Then use a sharp knife or scissors to cut off the tips of the ports. Make sure you get epoxy on the threads of the screws as well. Allow the epoxy to cure for about 24 hours before using the basement.


How much does it cost to fix a crack in the basement wall?

Basement cracks can be repaired using a liquid concrete repair kit or an epoxy crack sealer. The cost to fix a crack in a basement concrete wall will vary depending on the size of the crack and the type of repair compound used. 

Epoxy crack sealers are generally more expensive than liquid concrete repair kits, but they are also more effective. The cost of the repair kit or sealer will range from $10 to $50. The total cost of the project will also depend on the size of the basement and the number of cracks that need to be repaired.


Why do concrete walls crack?

Concrete walls can crack for a number of reasons, including foundation settling, basement waterproofing issues and excessive moisture. Foundation settling is when the ground underneath the foundation adjusts, causing the foundation to sink. This can happen when the foundation is first built or many years later. Basement waterproofing issues can also cause concrete walls to crack, especially in an old house.

Excessive moisture in the basement can cause the concrete to expand and crack. Improper basement waterproofing can also lead to basement leakage and flooding, causing the concrete to crack. Homeowners might want to consider installing a sump pump to avoid basement flooding. Landscaping that doesn't slope away from the foundation can also lead to basement flooding and concrete wall cracks.


Do cracks in basement walls have to be repaired?

Cracks in basement walls can be dangerous and lead to serious damage to the home if left untreated. Foundation cracks can allow water and moisture to seep into the basement, which can cause mold and mildew to grow. Cracks can also weaken the structure of the basement wall and cause it to collapse.

Take care of leak repair immediately. Radon is another concern with a cracked foundation. Radon is a colorless, odorless gas that can seep into homes through cracks in the basement and cause health problems. For these reasons, it's important to repair any cracks in your basement walls as soon as possible.

The different types of cracks can indicate a specific root issue. Horizontal cracks are often caused by basement waterproofing problems or foundation settling. Vertical cracks can be caused by basement waterproofing issues, foundation settling or excessive moisture. Stair-step cracks are usually caused by foundation settling. They get their name because they look like stairs.

Hairline cracks are often caused by basement waterproofing problems, foundation settling or excessive moisture. If they are just surface-level cracks, the easiest method to fix them is using urethane caulk. While it’s tempting to whip out the caulking gun for a quick fix, know that caulking is a surface-level, temporary fix.

In most cases, basement wall cracks can be repaired using a concrete repair kit or epoxy sealer. However, if the cracks are due to foundation settling, basement waterproofing issues or excessive moisture, consider consulting a professional for basement waterproofing or foundation repair.


Protect your home from costly repairs with a Cinch home warranty

Basement wall cracks can be dangerous and lead to serious damage to your house if left untreated.

If you're concerned about basement wall cracks and the potential damage they can cause, consider protecting your home with a Cinch Home Services protection plan. Cinch home warranties cover the repair or replacement of many items in your home, including many of your home's built-in systems and appliances, such as your furnace, water heater and air conditioner.

A Cinch home warranty can give you peace of mind knowing that if something goes wrong, we're here to help. With a Cinch home warranty, rest assured that your house is protected against costly repairs.

Get an instant quote for a Cinch home warranty!


Do you have a basement wall crack or basement floor crack? Learn how to DIY basement crack repair in this guide.