Why are there cracks in my seawall?

Are you concerned about the cracks visible in your seawall cap or panels? The level of concern is dependent on the size, location and number of cracks.

Why are there hairline cracks in my concrete seawall cap?

Concrete, like all materials, shrinks and contracts with changes in temperatures. As the concrete heats up it will expands and as it contracts the concrete will shrink. These changes lead to thermal stresses which generate hairline cracks to alleviate this stress.

Can you prevent hairline cracks in a concrete seawall cap?

Yes, you can substantially limit the number of hairline cracks in a seawall by starting with expansion joints set at regular intervals. These expansion joints are generally designed on 40' to 60' spacing. Cracking can also be reduced by having a seawall designed in accordance with the American Concrete Institute (ACI) Standards for structural concrete by a professional engineer. Generally, the area of steel in a caps cross section should be no less than 0.2% of the caps cross section. If the ACI standards doesn't sound like an exciting read, consider retaining a professional engineer to assist with a seawall design.

Are hairline cracks in a concrete seawall cap bad?

Hairline cracks in a concrete seawall cap can lead to saltwater intrusion, which may corrode the steel reinforcement located inside the cap. They should be avoided, however, do not necessary require an immediate replacement.

How to tell when a crack is structural?

A professional engineer should be consulted to assess the condition of structural concrete, however, as a rule of thumb any crack large enough to fit a coin is of concern. The remediation or replacement measures will depend on the size, location, and quantity of seawall cracks.

If you have any doubts about a seawalls structural integrity or want to have a better estimate to the walls remaining service life, please give us a call and we would be happy to send a registered engineer out for a site inspection.