Concrete cracks for many reasons—from natural shrinkage and temperature changes to water infiltration, corrosion, and structural movement. While some cracks are harmless, others can signal underlying deterioration. Understanding why concrete cracks can help property owners identify potential problems early and determine when professional assessment may be necessary.
Concrete is one of the most durable building materials in the world, but even well-designed and properly constructed concrete can develop cracks over time. In many cases, cracking is a normal part of a concrete structure’s life. In others, it can signal underlying deterioration that requires professional assessment.
Understanding why concrete cracks—and knowing which cracks warrant further investigation—can help property owners, managers, and facility operators make informed maintenance and repair decisions.
In short, yes.
Concrete naturally shrinks as it cures, and small shrinkage cracks are common. Temperature changes, environmental conditions, and normal structural movement can also cause concrete to crack throughout its service life.
The important question isn’t simply “Is there a crack?” It’s “Why did it crack?”
Determining the cause is essential for selecting the right repair strategy.
Concrete can crack for many different reasons, and more than one factor may contribute to the damage.
As freshly placed concrete dries and hardens, it loses moisture and naturally shrinks.
If this shrinkage is restrained, small cracks can develop. These are often narrow, stable, and considered a normal characteristic of concrete.
Concrete expands when heated and contracts when cooled.
Repeated seasonal temperature changes can create stresses within a structure, particularly if movement joints are inadequate or have deteriorated over time.
Buildings naturally move under changing loads, settlement, wind, and temperature fluctuations.
When movement exceeds what the concrete can accommodate, cracking may occur.
Structural movement should be assessed to determine whether repairs alone are sufficient or if underlying issues need to be addressed.
One of the most common causes of significant cracking is corrosion of reinforcing steel.
As rebar corrodes, it expands. This expansion places pressure on the surrounding concrete, eventually causing cracks that often run parallel to the reinforcing steel.
Without intervention, these cracks can progress to delamination and spalling.
Water entering concrete through existing cracks, failed waterproofing, or deteriorated sealants can accelerate deterioration.
Over time, moisture may contribute to freeze-thaw damage, chloride penetration, and reinforcing steel corrosion, leading to additional cracking.
In Canadian climates, repeated freezing and thawing place significant stress on concrete.
Water trapped within the concrete expands as it freezes, creating internal pressure that can gradually enlarge existing cracks or create new ones.
Concrete structures are designed to support specific loads.
Unexpected loading, repeated heavy traffic, or impact damage may result in cracking that requires engineering evaluation.
Not necessarily.
Many small, stable cracks are expected and do not affect the performance of the structure.
However, certain cracks should be evaluated by a qualified professional, particularly if they:
The pattern, location, width, and movement of a crack all provide important clues about its cause.
A condition assessment may include:
The objective is to identify the root cause rather than simply repairing the visible crack.
Repair methods depend entirely on why the crack developed.
Possible repair approaches include:
Selecting the appropriate repair strategy requires an understanding of the underlying deterioration mechanism.
While cracking cannot always be eliminated, proper design, construction, and ongoing maintenance can reduce its severity.
Best practices include:
Routine inspections help identify developing issues before more extensive restoration becomes necessary. Click here to read more on common signs your concrete structure may need repair.
A crack is a symptom—not a diagnosis.
Some cracks are simply part of concrete’s natural behaviour, while others may indicate corrosion, moisture intrusion, structural movement, or ongoing deterioration.
The key is understanding why the crack formed. By identifying the underlying cause, repairs can be designed to address the source of the problem rather than just the visible damage.
Early assessment allows property owners to plan repairs proactively, helping extend the service life of concrete structures while reducing the likelihood of more extensive restoration in the future.
Author
Joe Hoskins | Director of Operations, Retro Specialty Contractors
Concrete structures are constantly shifting due to thermal changes, settlement, and heavy load forces. In this guide, we break down what expansion joints are, how they function as critical relief gaps, and why installing the right system is essential for preventing severe cracking, water leaks, and long-term structural failure in BC commercial properties.
Expansion joints play a critical role in protecting concrete structures from movement, moisture and stress. Learn the 7 common causes of expansion joint failure—and how proper design, inspection and maintenance can help prevent costly damage.
PROJECTS Canada’s Largest Expansion Joint Project Oakridge Centre Redevelopment Vancouver, BC Project Value $16.9 Million Thousands of linear feet of specialized expansion systems Industry Recognition 2026 SWA Trillium Award Timeline 5 years (2021-26) Services Expansion Joints, Concrete Remediation, FRP Strengthening Specialty Contracting at a Different Scale Oakridge is the largest project in Retro’s history and […]
© 2026 Retro Specialty Contractors. All rights reserved. Privacy Policy | Terms & Conditions