Durability + Design

Building Performance and Aesthetics

A Product of Technology Publishing
JPCL/PaintSquare | D+D | Paint BidTracker

Subscribe to D+D Magazine
Durability + Design eBook: The Technology of Coatings in High-Rise Structures

Paint and Coatings Industry News

Main News Page


Witness: 9 Mall Areas at Breaking Point

Monday, June 3, 2013

More items for Building Envelope

Comment | More

Severe corrosion compromised nine areas of the Algo Centre Mall in Elliot Lake, Ontario, according to engineers who investigated the roof collapse that killed two people last June.

The panel of engineers, from NORR, were the among the latest witnesses—including architects, city officials, and building product manufacturers—called to testify before the Elliot Lake Inquiry.

“Many areas [throughout the structure] were depleted to the point where collapse could be imminent,” said Hassan Saffarini, the structural engineer in charge of NORR’s forensic inspection.

corrosion at Algo Centre Mall
NORR Report

A severely corroded steel beam fell through the roof of the Algo Centre Mall. The engineers testified that as many as nine beams were in critical condition and that any one of them could have caused a collapse.

The panel also testified Wednesday (May 29) on the design, construction codes and waterproofing issues at the mall. A series of other witnesses testified regarding pieces of the concrete slab that had fallen through the ceiling of a business at the mall.

NORR was retained by the Ontario Provincial Police after the rooftop parking garage tumbled down on June 23, 2012. The mall, built in 1980, has been demolished.

Corrosion Dangers

Saffarini identified nine areas in “critical condition” that posed an immediate threat to public safety, he said. Team members testified that they had safety concerns regarding the structure's stability when they inspected it July 25-28, 2012.

One of the most at-risk locations was a walkway near a shop entrance.

"There was a good probability it [steel beam] would soon have failed," said Saffarini. "The amount of corrosion was so severe the flange was almost completely depleted."

Earlier reports identified corrosion levels at the mall as like those observed in a marine-like environment.

Cause of Collapse

The testimony follows a 700-page report released by NORR in March 2013. The report, which has been key in the inquiry, identified the corroded beam connection that caused the collapse and further detailed the dilapidated state of the structure.

"The failure presented itself in a way that is clear," Saffarini testified. "There was a connection loss and a failure that resulted in the collapse."

Collapse
NORR Report

The Algo Centre Mall collapsed June 23, 2012, killing two and injuring others. The Elliot Lake Inquiry is studying the accident's cause and emergency response.

The 32-year-old structure leaked water from the day it opened until it collapsed. The combination of road salt and water had a lethal effect on the steel construction, according to NORR’s report.

With corrosion levels so severe, it took just one car driving over an unstable welded connection between a support column and beam to cause the cave-in. The collapse happend in one second, the engineers’ report said.

One engineer who had inspected the mall’s condition as recent as April 2012 has been charged with health and safety violations in the case.

Design Not Ideal

The NORR experts also noted that although the design of the uncovered rooftop parking garage in Northern Ontario was not an ideal choice, it did not contribute to the collapse.

“Avoiding rooftop parking all together would have been the simpler approach,” Saffarini said. “The fact that it was located in the North didn’t help.”

The experts further testified on the original design drawings, construction codes at the time, and waterproofing used on the mall, according to the transcript from Wednesday (May 29).

For example, NORR architect Chris Hughes said inconsistencies in the design documents were present and noted that the waterproofing sealer material “was not described in any way within the drawings or specification.”

“In fact, no specification was given to us for review,” he said. “Whether it didn’t exist or has been lost in time is unknown at this point.”

The overall design of the mall has been called into question at numerous points throughout the inquiry, as has the waterproofing.

City Knew of Falling Concrete

Recent testimony in the Elliot Lake Inquiry has also revealed evidence that the city knew, and was suspicious, of issues at the mall but did not act.

concrete
Elliot Lake Inquiry

Months before the building collapsed, pieces of concrete fell through the ceiling of businesses at the mall, according to evidence at the inquiry.

For example, city councilor Al Collet testified May 23 that he told the city building department about the state of the building a couple of months before the collapse, according to a report by one Canadian press agency.

He said a restaurant owner in the mall had showed him a “piece of concrete that had fallen through his ceiling and into his kitchen.”

Collet said he presented the concern to the chief building official, Bruce Ewald.

“His response to me was, ‘It's difficult, it would look very bad for the city to shut the mall down,’" said Collet. "My response to that—and I regret saying it now—was, 'What are we waiting for? Somebody to die?'”

The city’s building officials are required under law to fix or demolish buildings that are not watertight or structurally sound, the report said.

A structural engineer with Coreslab Structures, the manufacturer of the concrete slabs used on the project, confirmed in her testimony Tuesday (May 28) that the concrete that fell from the mall's roof was a section of the "actual slab."

The fracture, which resulted from the volume of corrosion pushing at the concrete, posed a "serious cause for concern," the engineer said.

Building Official Responds

Ewald testified May 27 that he had not seen the piece of fallen concrete as indicative of a structural problem and that he did not investigate the matter further, according to reports.

He admitted that he would have closed down the mall had he known of the more than 30 years of structural issues there. He also clarified Collet’s earlier statement.

Bruce Ewald
Elliot Lake Inquiry

The city's chief building official, Bruce Ewald, said a piece of fallen concrete had not indicated a structural problem to him.

“What I said was, 'What do you want me to do, Al? Close down the mall?'”

Ewald also said closing the mall “would have been economically detrimental to the city.”

Architect Warned on New Roof

Architect John Clinckett also recently testified that he was hired in 2007 to find a solution to the leak problem that had plagued the mall for so many years.

He had discussed building a new roof over top of the rooftop parking deck with the owner, but said that it would not have solved the issue fully.

"The cars would still be driving in. They would have snow on them, ice and salt. They would be driving in on the deck, dripping water, and it would leak through," Clinckett testified.

In addition, there were concerns about the weight of a second roof.

Therefore, the architect—just as many experts before him—recommended a waterproofing membrane, a suggestion rejected by the owner of the mall as too costly.

The inquiry will continue for several more months; dozens of witnesses have yet to testify.

   

Tagged categories: Architecture; Building design; Building envelope; Enforcement; Engineers; Fatalities; Health and safety; Parking Garages; Waterproofing

Comment Join the Conversation:

Sign in to our community to add your comments.

BASF
New resins from BASF will have metals loving water:

Excellent corrosion resistance, low VOC, high gloss, thin films basf.us/industrialcoatings
polyorders@basf.com
800-231-7868


Concrete Decor
2014 Concrete Decor Show

Learn valuable techniques and see the latest decorative concrete products at the 2014 Concrete Decor Show in Fort Worth, Texas, Sept. 29-Oct. 3. Register now!


No-Burn, Inc.
Designed to passively protect

Same trusted brand, new code compliant uses. We’ve answered the demand for better passive fire protection. Use coatings that meet the 2012 iCodes


Arroworthy
ArroWorthy's Handcrafted Professional Brushes

One Dip of paint with our handcrafted semi-oval Rembrandt brush, you'll see why ArroWorthy makes a professional brush of unrivaled quality and performance.


H&C Decorative Concrete Products
A comprehensive line for all your decorative concrete needs.

H&C® is committed to beautiful concrete protection and offers a variety of treatments and unlimited color possibilities.


Chemique Inc.
Paint Removal Made Easy!

Remove multiple coats in one application. Easy to use and safe. All products meet or exceed V.O.C. regulations. Contain no methylene chloride, methanol or petroleum distillates.


Westcoat
Bringing New Colors To Concrete Surfaces

Liven up your concrete surfaces with Westcoat's newest color choices. Introducing a myriad of Fast Stain, Liquid Dazzle, and Texture-Crete Interior colors.

 
 
 
Technology Publishing

The Technology Publishing Network

The Journal of Protective Coatings & Linings (JPCL) PaintSquare
Durability + Design Paint BidTracker JPCL Europe

 
EXPLORE D+D:      Interact   |   Blogs   |   Resources   |   Buying Guides   |   Webinars   |   White Papers   |   Classifieds
GET D+D:      Subscribe   |   Advertising Media Kit
KNOW D+D:      About D+D   |   Privacy policy   |   Terms & conditions   |   Site Map   |   Search   |   Contact Us
 

© Copyright 2010-2014, Technology Publishing, Co., All rights reserved
2100 Wharton Street, Suite 310, Pittsburgh PA 15203-1951; Tel 1-412-431-8300; Fax 1-412-431-5428; E-mail webmaster@paintsquare.com