18-ft fire-escape stair retrofit on a Brampton fulfillment building.

The brief

Building was originally a 1980s commercial / light-industrial use; the new tenant was running an e-commerce fulfillment operation that pushed second-floor occupant load past the threshold for the existing single interior stair. The municipal building department required two means of egress for the new occupancy. Adding a second interior stair would have required cutting through floor framing of the active operation. The exterior alternative was the practical answer.

The wall

South wall (where the stair would attach) was brick veneer over CMU, with an older-era brick tie pattern that wouldn't carry the stair anchor loads on its own. We needed to anchor through the brick into the CMU, with an engineered anchor design that distributed load across the wall rather than concentrating at any single tie.

Pre-attachment investigation included: brick coursing inspection, CMU mortar strength sampling, hidden-tie pattern verification, and test anchor pulls with calibrated loading. Test results came back below code-anticipated capacity, requiring additional anchors over a typical concrete-wall design.

What we built

• ConfigurationSwitchback (2 flights, 1 mid-landing)
• Total rise18 ft (second floor to grade)
• Stair width1100 mm clear (occupant-load driven, OBC §3.4.3)
• TreadBar-grate (snow / water shed)
• Top platform5 ft × 6 ft, integrating with existing egress door
• Mid-landing1100 mm × 1100 mm
• Guard42" with mid-rail and 4" toe-plate (OBC §3.3.1.18)
• Wall anchorsgalvanized through-bolts; count above typical for a concrete-wall design
• FinishHot-dip galvanized to CSA G164
• Service life expected40+ years (Ontario inland exposure)

Anchor design — the engineering effort

The anchor pattern needed to handle:

• Vertical load: full deck + occupant + snow loads, transferred through the stair stringers to wall anchors at landing levels.
• Lateral (pull-out) load: from wind on the stair structure and dynamic loads of occupants in motion.
• Moment load: at the connection between stair frame and wall, distributed across multiple anchors per flight.

Because the brick capacity tested low, we redistributed load across more anchors and added intermediate brackets between the primary attachment levels. Each anchor was specified as a galvanized through-bolt with epoxy injection at the brick / CMU interface to engage both materials. The stamped drawing called out the test pulls and the sample frequency for field verification.

Install — 3 days

• Day 1: anchor drilling and epoxy set; stair stringers field-set on cribbing.
• Day 2: stringer-to-wall connections; flight and landing welds; bar-grate tread set.
• Day 3: guard infill, top platform connection to existing door, sign-off walk with the building inspector.

Install ran during regular hours — the second-floor operation continued throughout. Truck access via a side parking lot meant minimal disruption to the loading dock on the front of the building.

Outcomes

• Permit issued and installation completed inside the same calendar quarter.
• Egress system signed off by the municipal building inspector at final walk.
• No structural callbacks at follow-up warranty inspection.

Client testimonial and exact dates pending publication approval.