6 Things to Know About Basement Wall & Floor Cracks
Who knew that one little word could mean so many different things? Crack: adj., super, first-rate; Crack: verb, break, usually into parts; Crack: verb, lose self-control; Crack: verb, hit very hard; Crack: verb, discover meaning, answer; Crack: noun, joke; Crack: noun, attempt to do something; Crack: noun, loud sound, usually from hitting; and finally, Crack: noun, break, crevice. Whew! That’s a lot of work for one little word.
And speaking of little, what about those tiny cracks that often appear in the concrete of your basement’s walls and floor–should you be concerned? What about the bigger ones? At what point should you start to worry?
3 Types of Basement Concrete Cracks in Foundation Walls:
1. Shrinkage or Curing
Concrete, by nature, shrinks as it dries and cures over time. The degree of shrinkage is largely affected by the conditions present at the time the concrete was poured and directly after. Dramatic changes in temperature can also affect curing and cause cracks to occur. Even in optimal conditions, however, basement concrete will experience some degree of shrinkage.
2. Settlement Cracks
Another often inevitable cause of cracking in basement slabs results from settlement in the soil beneath the slab itself. Most homes are designed to accommodate some movement in the soil, as it is a common occurrence. Other sources of settlement cracks include water leakage and aggressive tree roots.
A condition known as the frost-heave cycle explains how the moisture in damp soil under a home’s foundation freezes when cold and expands, then thaws, potentially shifting the concrete of the foundation and forming cracks in the concrete. Cracks caused by frost-heave are most often seen around the support columns of the basement floor, or as horizontal cracks along the upper part of a basement wall where it meets the surrounding topsoil, which is the soil most affected by the freeze-thaw cycle.
Potential Damage from Wall and Floor Cracks:
1. Water Leaks
Depending upon the size and amount of cracks in basement concrete, water can seep into the basement through them, which can in turn exacerbate the problem.
2. Structural Problems
Though most concrete cracks are not structural in nature, other types of cracks can be signs of more serious damage to a home’s structure. Take note of any of the following types of cracks or unnatural spaces in your home:
- Gaps forming between the floor and walls
- Gaps forming between the walls and ceiling
- Walls pulling away from each other
- Cracks on the walls, especially near corners
- Should any of these red flags become apparent, look for other clues that might suggest settlement issues, such as doors or windows that don’t open correctly or floors and surfaces that noticeably slope. Settlement is a problem best addressed sooner than later, as cracks will continue to form and the home’s foundation could suffer considerable damage.
3. Invasive Pests
While those minor settlement cracks may look (and even be) inconsequential, they can serve as a welcome spot for small pests to call home. Keep your eye on the cracks to make sure that you don’t have any uninvited guests taking up residence.
How to Fix Basement Floor Cracks
The best way to repair floor cracks is to pour in a polymer compound that forms a bond with the concrete on both sides. For wider cracks, use an epoxy filler to recreate the original monolithic pour. It’s important to do a thorough job of sealing the crack to prevent further issues, rather than just doing a cosmetic fix by covering it with a surface filler.