6,400 sqft storage mezzanine for a Mississauga 3PL.
A logistics operator running a 90,000-sqft Mississauga distribution centre needed to recover ~6,000 sqft of usable deck before a Q4 inventory ramp. Building had 28 ft clear, slab capacity in question, and a 5-day shutdown window in late October. We ran a single-tier 250 psf composite-deck mezzanine with two access stair towers and made the window.
The brief
The client's racking was at full utilization; new inbound product had been staging on dock floors. They had a fixed Q4 cutover requirement: deck operational and product moving before peak season. That set the install window to a late-October existing planned shutdown. Sign-off came in mid-summer, giving roughly 14 weeks to design, fabricate, finish, and install.
The slab question
The building was a 1990s-era tilt-up, originally specified for general warehousing. Slab thickness on the original drawings was at the lower end of what would carry the proposed column loads. At that thickness, we were at the edge of acceptable column-base bearing — possibly fine, possibly not, depending on slab edge condition and joint locations.
Core samples on multiple columns at site measure showed adequate concrete strength and thickness within tolerance for the era. Column baseplates were sized conservatively to spread load. This was the part of the design where the slab condition could have flipped the project to a tighter column grid; it didn't, but we wouldn't have known without the cores.
What we built
- Deck size6,400 sqft
- Live load250 psf
- DeckB-deck + concrete (composite)
- Clear height under deckforklift-clear (~13 ft)
- Column gridtypical 20 ft × 16 ft
- Stair towers2 (one main, one egress; both galvanized)
- Pallet drop1 (counter-balanced gate)
- Guard42" with mid-rail and kick-plate (OBC §3.3.1.18)
Specific member sizes and steel tonnage available on request to qualified buyers under NDA.
Install — 5-day shutdown window
- Day 1: staging — material lay-down per piece sequence in two staging areas; perimeter safety set; lift positioned.
- Day 2: column erection — all columns set and anchored; baseplate grout poured.
- Day 3: primary beam, secondary beam, bracing — frame complete by end of day.
- Day 4: B-deck installation, perimeter guard, stair towers field-set; concrete pour mid-day.
- Day 5: concrete cure (fast-set mix), guard infill, final sign-off walk with the facility manager. Demobilize.
What surprised us
The forklift clearance under the deck — we'd designed for 13 ft, which exceeds the client's reach-truck spec by 2 ft. At final walk, the facility manager asked if we could mark the deck height on every column. That became a standard handoff item we now do on every storage mezzanine: yellow-paint stencil on each column at exactly the underside elevation, so forklift operators have visual confirmation.
Outcomes
- Operational ahead of the planned cutover date.
- No structural callbacks at follow-up inspection.
- Meaningful incremental pallet capacity; client expanded inbound operations on the recovered cube.
Client testimonial and exact post-install metrics pending publication approval.