Cracks are a common sign and symptom of foundation failure. See our articles:
- Why Do I Have Cracks in My Home (Top 6 Residential Cracks)
- Top 5 Primary Reasons for Sheetrock Cracks
Not every crack in your home’s foundation is indicative of foundation failure or requires a major repair. Yes, slab cracks are often caused by settlement or heave, but here is a list of 5 crack types that don’t require major foundation surgery to fix.
1. Cracks Caused by Plastic Shrinkage
Water is key when mixing cement. When a slab is first poured, before it has cured and fully dries, this is referred to as a “plastic state.” The water evaporates and can result in significant voids between the cohesive particles.
Plastic shrinkage is usually the result of too much water in the concrete mixture and excessive heat.
This lack of continuity and filler results in fragile concrete that is predisposed to crack. The resulting fissures are called “plastic shrinkage cracking” in the industry.
Plastic shrinkage cracking is commonly located:
- Around pipes/plumbing fixtures
- Reentrant corners (hard corners that segue directly into the concrete slab)
The last is particularly true because concrete has difficulty shrinking around corners. The resulting stress results in concrete cracks emanating from corners. These cracks are narrow and hardly visible.
Despite their small nature, it is important to remember these cracks aren’t just surface blemishes but emanate deep into the slab itself. Control joints are utilized to control shrinkage and cracking.
*Note – the opposite of plastic shrinkage can also occur. When concrete is not mixed properly due to too much sand and other solid ingredients, it is referred to as a “hot load.” This does not cure as strong or stand the test of time as well.
2. Cracks Caused by Extreme Temperatures – Hot & Cold
Extreme temperatures can put undue stress on your foundation. Heat causes concrete to e x p a n d. We cover this in our article Heat & Foundations (3 Common Problems).
Concrete doesn’t flex or bend. It has no elasticity. So, when the concrete expands it cracks. Extreme cold can also incur severe damage to your home’s foundation via expansion.
When winter blusters in and deep-freezes set, this can raise the soil by inches. Frozen water expands by 9%. And thus begins the freezing and thawing cycle, a perpetual motion of up and down, weakening the foundation.
Unfortunately, your foundation was not built for lateral movement and cracks ensue. Our girl Katy Perry had it right in her song Hot N Cold, “You’re hot and your cold…you’re up and you’re down.”
3. Cracks Caused by Roots
We’ve all seen roots tear up a sidewalk, resulting in uneven surfaces like distended veins pushing up from the earth. Tree roots can tear up a foundation slab just like a bike path, particularly if a tree is too close to the home.
Roots wriggle and creep through the deep in search of moisture. Your home is a perfect place for roots to grow toward, especially if there is a leak. Before laying a fresh slab, consider removing trees in the immediate vicinity.
If you’re dealing with root damage, consider clearing the trees that are the most likely culprits. However, removing roots can result in voids underneath your home, causing the soil to concave.
Homes follow the laws of gravity and will begin to sink if the void is significant enough. Cut down the trees and fix any corresponding cracks later.
4. Cracks Caused by Plumbing Leaks
Moisture and concrete don’t mix well. Okay, that’s not quite right. Incessant moisture and cured concrete don’t mix well and can result in spalling and other structural damage. Plumbing leaks are notorious for creating a void underneath a home which results in slab cracking.
5. Cracks Caused by Drying
Occasionally, the concrete dries too quickly and results in “spiderweb cracks.” While these crazing cracks are likely to appear, they are simply a cosmetic concern and not a structural issue.
How to Treat Cracks Not Formed by Foundation Settling or Heave
Cracks are inevitable and not all pose a threat to your foundation. However, for those larger cracks that definitely require repair, there are solutions. We repair cracks with carbon fiber staples and epoxy.
See our article: Carbon Fiber Staple Repair.
Choose Dalinghaus for Your Crack Repair Needs
In summary, we’ve covered:
- Plastic Shrinkage Cracks
- Extreme Temperature Cracks
- Root Cracks
- Plumbing Cracks
- Premature Drying Cracks
And the best way to deal with these cracks is with epoxy and carbon fiber staples. We would be happy to inspect your foundation and assess your cracked slab.
Here at Dalinghaus Construction, Inc.: we respect your time. We tailor-fit your foundation repair & retaining wall’s repair plan to meet your unique needs. We also perform excellent foundation repair.
We do foundation underpinning and retaining wall repair the right way. With over 100 years of combined experience and 4.9 stars out of over 300 reviews – we are here to ensure that you never settle.
Check out our case study: Repairing Settling Tilt-Up In Diamond Bar
Take a crack at our article How Are Foundation Cracks Repaired? (Ways Foundation Repair is Done)
If you live in SoCal or Arizona and would like a FREE crack inspection, click the link below –