Connections Are Where Steel Frames Actually Work
A steel member is straightforward: you size it for the load, and the code tables or design software tell you whether it works. The connection between two members is harder — it has to transfer the forces the analysis assumed it would transfer, it has to be buildable, and it has to be inspectable.
Most of the problems we see in structural steel don't come from undersized beams. They come from connections that were never detailed for the forces actually arriving at them — or that were detailed clearly but built differently on site.
Bolted vs Welded: The Real Trade-offs
| Aspect | Bolted | Welded |
|---|---|---|
| Field conditions | Tolerant of weather and cold | Sensitive — wind, moisture, and temperature all affect quality |
| Inspection | Simple — visual and torque verification | Requires qualified inspection, often NDT |
| Speed on site | Fast, minimal equipment | Slower, needs a qualified welder and power |
| Tolerance for fit-up | Forgiving with slotted or oversized holes | Requires close fit-up before welding |
| Where it's used | Most field connections, simple shear | Shop fabrication, moment connections, complex geometry |
The practical rule: push as much work into the shop as possible, and keep field connections bolted. Shop welding happens under controlled conditions with proper fit-up and access. Field welding happens in Ontario weather, often at height, often with the member already positioned. The quality difference is not about the welder's skill — it's about the conditions.
This is why our drawings specify bolted connections for field work wherever practical, even when a welded detail would be marginally more efficient. Reliability on site beats elegance on paper.
“A weld specified for the field is a weld made in the weather, at height, in whatever position the member happens to sit. A bolt doesn't care about any of that.”
Where Connection Problems Actually Show Up
Forces the analysis didn't anticipate
A connection detailed for shear alone, when the frame relies on it for lateral stability. The members are right and the connection is wrong — a failure mode that only appears under the load case it wasn't designed for.
Tolerance and fit-up issues in the field
Steel arrives with mill and fabrication tolerances, and concrete has its own. When they stack up, members don't meet as drawn. The site fix is often a field modification — which is exactly what needs engineering review, not improvisation.
Missing or substituted fasteners
A bolt size or grade swapped for what was on the truck, or a required hole not filled. Subtle on site, significant structurally, and invisible in a final photograph.
Corrosion protection gaps
Galvanizing or coating damaged during erection, or cut edges left unprotected. In Ontario's freeze-thaw and salt environment, an unprotected connection can degrade years before the members around it.
Sequence and temporary stability
Steel frames are often not stable until a sequence of connections is complete. Erection that gets ahead of the bracing or temporary support plan is a genuine safety concern, not just a schedule one.
What Shop Drawings Have to Show
The steel shop drawings are where the design connection becomes a fabricable one — and where an engineer's review catches problems before steel is cut:
- Every connection, detailed — plate sizes and thicknesses, bolt diameter, grade, count, and hole type; weld sizes, types, and lengths.
- Member sizes as fabricated, reconciled against the structural drawings — including any substitutions, which need review rather than acceptance.
- Erection and bracing information — how the frame is stabilized during construction, and in what sequence connections are completed.
- Clear identification of field versus shop work, so nothing specified for controlled conditions gets shifted to site.
Our guide to shop drawings in Ontario covers the review and approval chain in full, and the steel and curtain wall coordination post addresses what happens when facade and structure drawings are reviewed in isolation.
Why Winter Is Actually a Good Steel Season
Steel erection is one of the few exterior activities largely unaffected by cold. It doesn't require curing temperatures the way concrete does, and it isn't dependent on dry conditions the way roofing is. Ontario winters often bring firm, dry ground that makes site access for heavy steel easier than a muddy shoulder season.
That makes steel a practical winter work package — which is worth knowing if you're planning a commercial or industrial build and want to keep the schedule moving. See our winter construction guide for how the rest of the sequence fits.
Structural Steel Across the GTA
Local requirements and inspection practice vary by municipality. Find your city:
May Engineering Inc: Steel Design and Shop Drawing Review
May Engineering Inc designs structural steel frames and connections, prepares sealed structural drawings, and reviews shop drawings on behalf of the design engineer. We specify bolted field connections wherever practical, detail for buildability, and flag substitutions before they become rework.
Working on a steel-framed project or reviewing shop drawings? Send us the drawings and we'll tell you what needs attention before fabrication.
Steel frame or shop drawings?
Free initial consultation. Sealed structural design and shop drawing review across Ontario.