Stainless steel key to Confederation Building repair in St. John’s, Newfoundland

Repairs on the masonry of the Confederation Building in St. John’s, Newfoundland are being completed with an anchoring device supported by a rod of stainless steel. Much of the masonry is being remediated through the use of a stainless steel anchoring system supplied by Cintec Reinforcement Systems of Ottawa.

The Confederation Building in St. John’s,N.L. has been the primary seat of the provincial government since it was opened in 1960. Current repairs on the building’s masonry are being completed with an anchoring device supported by a rod of stainless steel.

In 2008, the province’s Department of Transportation and Works engaged consultants to evaluate the condition of the building’s exterior. The consultants reported that some of the windows and exterior masonry had deteriorated to the point where they had become a potential safety risk.

“Based on the results of analysis of the condition of the East Block by a number of building experts, we have begun the process of replacing windows and refurbishing masonry,” says Transportation and Works Minister Tom Hedderson.

The technology works by drilling a small hole into the masonry and inserting the anchor, which consists of a type 304 stainless steel rod inside a balloon-like sock. Contractors inject grout into the sock until it fills all of the voids inside the masonry. When the grout hardens, the steel rod provides tensile strength to hold the repair in place. The small hole drilled to insert the anchor is later repaired.

“This isn’t an off-the-shelf product,” says Gene Quesnel, technical consultant with Cintec Canada. “The grout is mineral-based and includes no epoxies or resin binders. We don’t like to introduce foreign material into the structure if possible. The grout is injected into the cavity under low pressure. Each steel anchor and sock is designed to suit the parameters of the project and manufactured to project specifications.”

Cintec representatives engage contractors in training sessions so they can install the product properly. Quesnel personally instructed workers with Limen Group, the company subcontracted to perform the masonry work in St. John’s.

“In this case, the brick façade of the building is delaminating and starting to fail,” says Quesnel. “So the government is faced with the choice of either repairing it or replacing it. With a heritage building of this sort, it has a place in the hearts of the people as a building that their parents or grandparents may have helped to build and replacing the brickwork would reduce that historic connection. Part of the installation process is to be as unobtrusive as you can.”

Arran Brannigan, vice-president of operations for Limen Group reckons the job is currently the largest masonry restoration project in Canada. In addition to the remediation work, which includes installation of 13,000 anchors, the contractor is removing and repointing more than 500,000 feet of mortar joints. On average, the project employs 15 workers.

“According to Environment Canada, St, John’s is the windiest city in Canada,” says Brannigan. “The Confederation Building is located on the top of a hill and on a cold day, 100-kilometre winds are a challenge.”

A unique aspect of the project involves the stabilization of the parapet along the building’s roof.

“If this part of the building collapses, you’d lose the top part of the wall,” says Quesnel. “To stabilize this section, we drilled in-plane horizontal holes for Cintec anchors with stainless steel rods over six feet long around the perimeter.”

Longer steel anchors were recently used in a school project for the Toronto District School Board.

“The concrete blocks were destabilizing and beginning to delaminate,” says Quesnel. “Rather than tear down the wall and rebuild, we brought in a crane and drilled anchor holes 20 feet down, manufacturing 20-foot anchors to be inserted vertically, straight into the foundation.”

Another Cintec division designed steel anchors more than 100 feet long for seismic upgrading of Christ Church Cathedral in Newcastle, Australia.

Cintec’s parent company in Wales is also completing work on Egypt’s Pyramid of Djoser, which was damaged by a 1992 earthquake.

“Whether the building is 50 years old or 5,000, the repair and stabilization concept is virtually the same,” says Quesnel.

Work on the Confederation Building is expected to wrap up in 2013.