Concrete is one of the most durable building materials. There’s no debating there. It’s strong in compression, weak in tension and shear, but since concrete (in construction) is used in the form of ‘reinforced concrete’ which combines the material with steel rebar, making it strong in both compression AND tension.
It’s no wonder you see concrete everywhere and most massive cities are called ‘concrete jungles’.
But still, regardless of how great the material is, it still has its own set of problems. Hidden, silent, and deadly things that can destroy it.
In this article, we’ll go over things such as poor curing, soil insufficient soil preparation, overloading can cause the concrete to craft and/or crumble.
Let’s get concrete!
The Cold Beneath
Why It Happens:
A constant problem in colder climates (e.g., Minnesota, Pennsylvania, Connecticut, Michigan, etc.) water seeps into soil, freezes, and expands. The concrete lifts and when the ground thaws, the ground can collapse, leaving uneven slabs in your driveway and even your foundation.
Signs You Have It:
- ‘Pop-up’ cracks in early spring
- Frost heave (concrete bulges in winter)
- Crumbling edges from repeated stress
The Fix:
- Proper sub-base materials (e.g., crushed stone) for drainage
- Adequate expansion joints to absorb movement
- Concrete sealing to minimize water penetration
This erosion of any kind of soil becomes the bad guy under your feet.
Erosion
Why It Happens:
Water runoff, poor drainage, or even burrowing pests can erode all types of supporting soil. The American Society of Civil Engineers warns that erosion causes $2B+ in infrastructure damage yearly, so your residential slab isn’t immune. Clay soil is common in the PA area, but other soils cause erosion as well.
Signs You Have It:
- Exposed slab edges or ‘overhanging’ concrete
- Sinkholes or depressions near downspouts
- Mud streaks after rain (indicating soil loss)
The Fix:
- French drains or swales to redirect water
- Gravel backfill to stabilize eroded zones
- Root barriers if nearby trees are the culprits
Expansive Clay
Why It Happens:
Clay soils absorb water like a sponge. It swells up in volume during rainstorms, then dries and shrinks. This constant movement lifts the cement, causing it to crack. Innovations in soil erosion are being made nationally every year, but see below to determine if this is your issue and how to fix it:
Signs You Have It:
- Seasonal cracks that widen in summer
- Doors/windows sticking in humid months
- Visible gaps between soil and slab edges
The Fix:
- Proper grading to divert water away from slabs
- Soil stabilization with lime or cement mixtures
- Concrete lifting (for sunken sections) to restore levelness
Tip: In Harrisburg, PA, where clay-rich soils are common, search online for ‘concrete lifting near me’, and an expert can come out to re-level sunken driveways or patios.
Compaction
Why It Happens:
When getting the surface ready for concrete, the soil needs to be lightly compacted before pouring. If it isn’t, the soil will settle over time and can create voids. This tends to be in new construction, where the builder takes a shortcut.
Signs You Have It:
- Hollow sounds when tapping the concrete
- Sudden dips or sinking in high-traffic areas
- Cracks radiating from corners
The Fix:
- Polyurethane foam injection fills voids without excavation
- Mudjacking (slab jacking) lifts and re-supports sunken concrete
- Prevent future issues with proper soil testing before installation
Inadequate soil compaction leads to uneven load distribution beneath concrete slabs. This results in void formation and long-term structural instability, which leads to cracks and other types of damage.
Organic Decay
Why It Happens:
Another foundation stressor is the decomposition of tree roots and buried organic matter that creates empty spaces where the soil will collapse into itself, causing concrete to sink.
Signs You Have It:
- Sinking near tree stumps or old landscaping
- Spongy ground near slab edges
- Mushrooms or fungi growing through cracks
The Fix:
- Remove decaying roots and backfill with compacted soil
- Foam jacking to lift affected slabs
- Strategic planting to avoid future root intrusion
As buried organic matter decomposes, it reduces soil density/volume. This creates a subsurface void that compromises slab support, which’ll result in differential settlement and damage.
Conclusion
Soil is a ‘living’, moving, changing system. That’s why it directly impacts any structure that’s sitting on top of it. And concrete, regardless of how durable it is – is absolutely no exception.
You may create a foundation that you deem good enough, and you might successfully pour that reinforced concrete as a base. But if you’ve ignored many of the things we went through in this article, you’re concrete – regardless of how durable you think it is – will undoubtedly suffer.
It isn’t a question of “If?”, but rather “When?”.
Create a proper, solid, long-lasting foundation. After that, pour quality concrete (not cheap or improperly mixed ones) paired with great-quality steel rebar (epoxy-coated or galvanized). Only by doing it the proper way can you be certain that the structure – regardless of what it is – will stand, last, endure… for decades to come.
Let the facts cement so that you’re left with a solid foundation!
