Cracks appear at Blue Bombers' new stadium

The Winnipeg Blue Bombers won'thave to foot the bill for any repairs due to cracks at Investors Group Field, the CFL team's brand-new stadium.

Investors Group Field has not even hosted its first regular-season CFLgame yet, and alreadythere are visible signs of wear and tear on the building. Cracks have begun to emerge in the stadium's concrete, withsome as big as a centimetre wide.

From ramps to stairs to concourse floors, the cracks are everywhere. Some have even been filled in.

'Cracks are always a way of the concrete telling you it's not happy something is wrong and you got to take a look at it.' Fariborz Hashemian, University of Manitoba

Construction ofInvestors Group Fieldwas overseen by BBB Stadium Inc., a consortium involving various levels of government and the University of Manitoba, where the stadium is located.

City of Winnipeg chief administrative officer Phil Sheegl, who is the city's representative in the consortium, told CBC News on Thursday that Stuart Olson Dominion, the stadium's general contractor, is responsible for any repairs to the cracks.

The Blue Bombers organization also confirmed that the contractor is responsible for addressing the cracks.

However, a statement from Stuart Olson Dominion says the cracks are not structural and the stadium has been inspected and certified by engineers.

According to University of Manitoba civil engineering professor Fariborz Hashemian, cracks in concrete aren't unusual but they can be prevented.

Hashemian said he could not comment on Investors Group Field specifically, but he said if concrete isn't given enough time to cure it can crack easily.

"You need to give it enough time, enough moisture to keep it at the proper temperature for the curing process to happen properly," he said.

He said cracks can be reduced by designers.

"There's also some detailing that we can put into our design by putting in control joints or crack control joints or contraction points where we tell the concrete where to crack, basically," said Hashemian.

'Not acceptable'

But, the professor added anything beyond a hairline crack could be a warning sign.

"Cracks are always a way of the concrete telling you it's not happy something is wrong and you got to take a look at it," he said.

A number of local engineershave been reluctant to discuss the Investors Group Field cracks, specifically, with CBC News.

But an engineering professor at McGill University, who specializes in concrete, agreed to review some video and offer some insight.

"On a public structure like this, where you know, thousands of people will be coming to events, it's not acceptable," said Saeed Mirza.

"If I'm designing something, my expectations will be that that structure will not crack."

Mirza said cracking happens all the time and hairline cracks are acceptable, but anything larger can cause moisture to seep into the structure and could cause permanent and extensive damage.

He added an inspection of the stadium would need to be done to see exactly what happened to the concrete and what remedies might be needed.

Cracking 'very common', says contractor

Officials with Stuart Olson Dominion told CBC News the cracking is only on wearing slabs and is non-structural.

The cracks appear only on a thin "topping" of insulation, the company said.

Company officialssaid concrete in that application could shrink and expand as it cures, and cracking is unavoidable and very common.

They added the structure was inspected and certified by engineers.

Mirza agrees but said there is much that can be done to mitigate the size of cracks.

"The engineer has to control that shrinkage in such a way that your cracks, these wide cracks, don't appear," said Mirza.