How Plants Cause Concrete Sidewalk Cracking ​

Concrete sidewalk cracking often occurs due to soil expansion, upheaval or freeze-and-thaw cycles. Sometimes, however, plants – even small ones – can be the source of this problem.

How is it possible for a fragile little plant to break through solid concrete? And can you do anything to prevent this annoying and costly problem?

concrete cracking

Weeds and Small Plant Roots Exploit Existing Concrete Cracks

As you may suspect, tiny little plants don’t actually have the power to cause concrete sidewalk cracking. Instead, the plant’s roots take advantage of existing microscopic cracks.

New cell growth takes place at the tips of plant roots. As the root system grows and develops, these tips act as feelers, seeking out the path of least resistance for expansion.

These pervasive little root tips can detect microscopic fissures in the concrete surface and, once they find one, the root pushes into the tiny crack. Eventually, molecule by molecule, the plant’s growth can force its way into the slab and create a surface crack.

Talk about a mustard seed moving mountains!

Concrete Sidewalk Cracking May Be Caused by Tree Roots

In some cases, you may see grass or weeds growing out of cracks, but that doesn’t mean they’re responsible for the damage. The real culprit could be the bushes and trees growing near the cracked sidewalk.

Sidewalks that crack in an “A” formation or that also have lumps likely have large roots running underneath. But, as with the cracks that are caused by weeds and small plants, the roots are not breaking the concrete without a little help.

Sidewalk lumps are the result of large root systems growing underneath the slab. This growth creates a hard point in the soil that is surrounded by softer dirt. Over time, constant foot traffic and extreme weather conditions cause the sidewalk to crack. The resulting segments of the sidewalk settle and form a dangerous, uneven surface.

Repairing Concrete Sidewalk Cracks

In most cases, repairing concrete sidewalk cracks is a simple process that doesn’t require a large investment of time or money. Slabjacking, also known as mudjacking, can easily fix the damage.

Mudjacking is much less expensive than replacing the concrete sidewalk slab, and the repair is much less intrusive.

Repairing concrete cracks with slabjacking requires the contractor to drill a few small holes in the concrete, then pump in a slurry mixture. Once the mudjacking mixture is injected, pressure lifts the sidewalk back to its original position. After the repair is complete, the holes are filled, the crack is caulked and the surface looks as good as new.

To stop sidewalk concrete cracks from returning, you will have to address the growing root systems of the offending plants. Weeds, grass and small plants growing in the cracks should be removed by the root. Trees and large bushes can be transplanted to another location or, if that’s not possible, root barriers can be installed.

Lift Right Concrete LLC, northern Utah’s leading professional slabjacking repair specialists, can fix cracks in concrete sidewalks, patios, driveways, garages and other outdoor concrete slabs. Call our West Jordan office today to schedule a free repair consultation and estimate for your concrete sidewalk cracking.