The Challenge
When a firewall exceeds traditional warehouse heights, the temperature gradient under fire conditions causes considerable lateral bowing of the wall, which could collapse under its own self weight if not properly designed and supported.

The designers had to develop a new wall system for walls exceeded 18 meters in height that would perform during a fire.

The Project
To meet the performance criteria, the fire separation was to be comprised of (2) 3 hour rated walls laterally tied to internal steel framing. The precast panels were 180mm thick, 2400mm wide and were vertically stacked in 6 meter increments.

During a fire the steel and attached wall will fail at one hour. The remaining wall would remain in place to provide the additional 3 hour protection. Each precast panel was constructed using a combination of conventional steel reinforcing and prestressing. A special fire resistant sealant was used in the panel joints to prevent the passage of flames or hot gases and the transmission of heat across the joint.

The Triumph
The precast manufacturer had previous experience with the construction of a precast firewall system at the 92,900 sq m Canadian Tire warehouse facility in Brampton. The precaster's construction personnel were able to quickly assemble the firewalls, streamlining the schedule and successfully completing the project. A total of 2128 precast concrete firewall panels measuring 32,416 sq m were installed in the Sears Warehouse project. This Belleville warehouse complex is the company's largest in Canada, that now has 1,500 employees.

Credits:
Owner: Sears Canada
Consulting Engineer: NLK Consultants Inc., Vancouver, B.C.
Precast Contractor: Pre-Con Inc.