Heat wave caused sidewalks in Waterloo Region to buckle

Extreme heat can cause sidewalks to heave, or buckle. CTV’s Colton Wiens finds out why.

The heat wave may be over, but Waterloo Region still has to deal with the side effects.

Sidewalks in Waterloo, Kitchener and Cambridge have buckled under the stress of the heat and humidity.

Most are made of concrete and when the temperature rises, the material expands. However, since the slabs are so close together, the pressure causes the concrete to crack or forces it upwards.

In Waterloo, a portion of the sidewalk on Marsland Drive was cordoned off Thursday due to the damage.

Buckling was also seen in two spots along Erb Street in Waterloo.

The city said it planned to fix the sidewalks by the end of the week.

“I could definitely see anybody with maybe a wheelchair, or somebody with some type of a disability not being able to get around it,” observed Waterloo resident Alexander Lefebvre.

Cambridge said it received similar buckling reports, including one sidewalk in West Galt and another in the Preston area.

“The city is aware of two locations where sidewalks have buckled due to heat stress over the past week,” they stated in an email to CTV News. “Fortunately, in Cambridge, this has been rare.”

The City of Kitchener said they received five reports of sidewalk buckling this week, and one of them has already settled back into place.

“Sometimes these areas will go back down on their own after the heat dissipates, but sometimes they’ll require further intervention,” they explained. “When we see a sidewalk heave, we will typically make the area safe through visual markings like cones or paint and will monitor the area. Depending on the situation, we will replace the affected area if necessary.”

The City of Kitchener encourages anyone who spots sidewalk buckling to report it online.

What is heat buckling?

Pejoohan Tavassoti, an assistant professor of Civil and Environmental Engineering at the University of Waterloo, said buckling and heaving are not common in Ontario – except when it comes to extreme heat.

“That is causing what is known as the thermal expansion of concrete,” he explained. “Like any material, concrete naturally expands when temperatures rise. Under normal conditions we expect this expansion to be accounted for with properly designed joints or accommodation in the structure. So, it moves slightly without causing any damage. But when we experience rapid temperature spikes like what we had a couple of days ago, or prolonged heat waves, typically, those materials expand more than usual. If the sidewalk doesn’t have enough room to expand or if joints are clogged or any sort of damage is there, the pressure build up actually forces the stuff to eventually lift or buckle upwards.”

With extreme weather events happening more often, experts are looking for new ways to prevent heat buckling.

“How to make small adjustments in the joint design, in drainage, all that stuff that hopefully will somehow help out with resolving this issue or minimizing the impacts,” Tavassoti said.

- With reporting by Colton Wiens