Despite its strength, concrete work may crack and degrade. Knowing when defects signal a significant problem allows you to schedule timely repairs of driveways and basement walls and floors when necessary.  Here’s what you should know about four types of concrete cracks.

A Guide to Concrete Cracks

1. Settlement Cracks

The soil underneath concrete isn’t always completely solid. For example, trenches constructed to service utility lines may disrupt concrete work, causing a long, straight rift to form across a surface. Settlement cracks are usually easy to diagnose, especially when there’s been excavation work in the area that shifts the ground nearby. 

2. Plastic Shrinkage Cracks

Immediately after concrete is poured, it contains a significant amount of water. Water that seeps away too quickly from newly poured walls and floors may weaken their structure. Cracking may occur around embedded fixtures, such as drains, where concrete “shrinks” around them. Usually long and thin, they are often challenging to detect without specialized training. 

3. Heaving Cracks

The freeze-and-thaw cycles also play a role in concrete damage. As the ground freezes, it may heave upward. When it thaws, it sinks back down. Repeated instances of freezing and thawing may cause a mosaic of cracks across a concrete slab. 

4. Expansion Cracks

When the weather warms up during the summer, concrete can expand and push against surrounding structures. If these structures are impermeable, a concrete surface may buckle and crack around expansion joints, which separate slabs into sections.