Concrete workers at a home in Whyte Ridge put their day job aside Tuesday to detour traffic after the heat caused a section of nearby Scurfield Bouelvard to heave up into a ramp, opening up big holes in the roadway.

A crew from local concrete business Muddruckers happened to be doing work on Debby Doig's back patio on Portwood Drive Tuesday when they noticed the street open up on Scurfield. They dropped what they were doing to divert traffic until police and city crews showed up.

"They were terrific," Doig said. "They slowed all the traffic down, they stood out there in that hot sun and they took care of the neighbourhood."

A city spokesperson said concrete pavements expand when heated, and that's what happened Tuesday when Winnipeg saw highs in the 28 C range.

Police divert traffic away from the damage section of Scurfield Tuesday evening. (Lara Schroeder/CBC)

Parts of jagged concrete almost a metre and a half in height jutted up from the road and presented a traffic hazard, she said. The heave went all the way across the road and extended to the sidewalk on the other side of a grass boulevard.

Shane Willim, one of the Muddruckers employees, said the crew heard "big bangs" between 3 p.m. and 4 p.m. Those noises drew them away from Doig's patio to see what was happening.

"Saw that cars were launching off the heave in the street that had formed a decent-sized ramp," Willim said in a text on Wednesday. "Didn't want people damaging their vehicles or getting hurt."

Watch vehicles scrape across the 'ramp':

Vehicles driving down Scurfield Boulevard Tuesday night encountered an obstacle: a 'ramp' of heaved concrete formed amid hot conditions that expanded the road. 0:21

The crew grabbed pylons and caution tape from their work truck to block off the most dangerous parts of the road. Then Willim and others slowed and redirected traffic for about an hour and a half before police arrived and took over, he said.

Signage and a detour were in place at Scurfield and Wittenberg Road overnight, Doig said, and city crews arrived to repair the hole early Wednesday morning.

City workers repair the damaged roadway on Scurfield Boulevard Wednesday morning. (Supplied by Debbie Doig)

Dave Knapp, co-owner of Muddruckers, said he is proud his crew sprang to action before someone got hurt.

"They were right there when it happened," he said. "They came to the rescue. We were giving them compliments this morning."

Doig said she walks her dogs down Scurfield every day and there were no visible signs of damage at the surface before the road heaved.

"It just happened. There was no crackage," she said. "I never saw that happen before."

Though the scale of the heaving on Scurfield is something she's never seen, Doig said the road quality in Whyte Ridge has deteriorated in recent years.

"We definitely have a problem with the road situation," she said. "I think this is just the start of what's going to happen. I think they're atrocious in Whyte Ridge."

A city spokesperson said one westbound lane of Scurfield will reopen Wednesday afternoon, but it could take until next week to finish repairs.