How to Fix Concrete Cracks in Your Basement During Renovations

How to Fix Concrete Cracks in Your Basement During Renovations
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    The basement often doubles as a storage space, an extra work or play room, or even a guest room.

    However, many basements can be musty, dark, or even dangerous when not maintained.


This is especially true when the concrete develops cracks. Children and adults can trip over them or even be cut by cracks.

Cracks in the basement are simply a part of a basement’s life. It is the nature of the concrete to settle after shrinking, which can create cracks. These cracks can then be exacerbated under extreme climate variances.

The challenge is that water can seep through the cracks and cause water damage. For this reason, it is important to know how to fix concrete cracks in your basement during renovations.

Filling cracks with Grout

The first step is to fill cracks with grout if you can. Small hairline cracks are not threat to the structural integrity of the house. However, they can widen and grow over time. You can mark the crack at both ends, write the date by the marks and check it on a monthly basis to gauge if there is any expansion occurring.

If the crack is stable, meaning no expansion occurs and no moisture is present, you can fill them with grout smoothing them over with a putty knife.

If the crack expands past your marks, then you’ll know that shifting and expansion has occurred, which may require professional appraisal and foundation repair.

Patching Basement Cracks with a Concrete Crack Filler

Grout will only be able to handle small cracks. If they are larger, you may require a more substantial filler. Cracks wider than between 1/8 and ¼ of an inch may be filled with concrete-compatible caulk.

A silicone caulk can be used to fill these cracks and will effectively seal them and prevent moisture, smells, or radon gas from seeping through.

You can double check with the EPA website learn if there is a radon exposure threat in your area. Be sure to check that these cracks are also not widening over months or years, as this will cause your crack filler to merely crack again.

Knowing When to Call in a Pro to Perform Repairs

While most cracks can be repaired with grout or concrete, you should be able to recognize signs of more serious foundational problems. There are some cracks that indicate the need for foundation repair.

For example, a crack where the basement floor meets the walls that’s larger than half an inch should be handled by a foundation contractor. Cracks of 2-inches or more are highly susceptible to moisture seeping through, which can increase a risk of mold and mildew.

It is important to keep water away from the foundation wall in general. If your basement does have a problem with mold, you may also need to call in a mold remediation specialist. Mold spores can spread rapidly and infect the lungs and throat, impeding your ability to breathe.

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      some home theater in the basement setup to consider      

If any of the cracks are bulging out, your concrete may be experiencing structural issues. Soil expansion can cause extra pressure that undermines the structural integrity of the house. It is best to leave these problems in the hands of the pros who can properly evaluate the extent of the repair required. It may be that you need concrete repair, soil stabilization, or foundation re-alignment.

Low-Pressure Crack Injection

Another method of repairing cracks is an injection process that uses a low-pressure tool to fill the cracks with an epoxy or polyurethane material. This epoxy will also seal them, preventing moisture contamination. Cracks may also be back-filled with sand followed by a self-leveling epoxy that produces a smooth surface.

This is a reliable, cost-effective and permanent method that does not involve any excavation. If you have the time and tools available, this option may be the best one for you.

Basements have a reputation for being damp. As basements lie below the ground level, the grading around the house should slope away from the structure. The rain and snow must be directed away from the house and yard and out onto the street.

other valuable tips:

Any cracks or bulges in the foundational structure must be checked in case there is the need to perform any excavation to repair the weaknesses. Once these challenges are met, you can put the effort to sealing the cracks in the basement to ensure the space remains dry and free of the mold and mildew that poses a health risk.

If your house sits on the lowest portion of the land, regularly experiences flooding or pooling, or frequently gets backed up pipes, this could be a sign that your foundation is sinking or has sunk in the past.

Be sure to talk to a foundation repair service about any sinking, cracks, or perpetual moisture and mold in the basement.

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Categories: Basement

About Author

Brook Chaplan

Brooke Chaplan is a freelance writer and blogger. She lives and works out of her home in Los Lunas, New Mexico. She loves the outdoors and spends most her time hiking, biking, and gardening. For more information, contact Brooke via Facebook at or Twitter @BrookeChaplan