How thick is a concrete sidewalk?

How thick is concrete sidewalk? Concrete sidewalks are generally 4” thick. This is the equivalent of 100mm of concrete. They can also be of a lower structural MPa design mix as they are not intended for great amounts of structural capacity or to support structures. Other considerations for the thickness of concrete sidewalks come at the portions of sidewalks adjacent to sloped surfaces or tying into the curbs structures and parking lot structures. 

You can often see these sorts of sidewalks with a thickness egged, going up to 150mm or 6” of concrete depth. This adds strength to the concrete sidewalk edge and helps to prevent upturning or sloping over time where one side is doweled into a supporting concrete element for instance. 

Another noteworthy point are ramp structures and concrete barrier-free access points.  Slope of concrete with these structures can often result in thickened portions of sidewalk.

It is essential for concrete thickness to be maintained throughout a concrete sidewalk element. So where detailed excavation permits, the thickness of the concrete can be carried through at the 4” level but where the detailed excavation is not sufficient, then it is likely that a higher depth of concrete sidewalk be used, such as 6” or even 8” just because it is simpler for installation. 

The extra concrete utilized in the process is not that much of a cost. Obviously on larger projects this can be a concern and larger concrete sidewalks, subgrade, base, and sub-base prep are essential to ensure the right quantity of concrete is used. 

The other factor that affects why concrete sidewalks should be at least 4” is the utilization of concrete reinforcement.  Reinforcement  needs adequate cover to ensure that it is protected from corrosion from the outside. The concrete cover provided by 4” or 100mm of concrete is essential to ensure that reinforcement stays intact throughout the lifespan of the concrete sidewalk.

Heavy duty sidewalks might be thicker, such as up to 6” or 150mm in some cases.

So generally speaking, a concrete sidewalk is at-least 5 4″ and can increase to 6″ in some cases.