Open Web Steel Joists in Ontario: A Complete Guide for Commercial & Industrial Builders
Published by Peel Welding & Fabrication — Mississauga, Ontario
OWSJ Installation, Reinforcement, Fabrication & Repair across the GTA
If you’re planning a warehouse, retail centre, school, office building, or multi-unit residential project in Ontario, the structural system you choose will shape your timeline, your budget, and your building’s long-term performance. For most non-residential floor and roof assemblies, Open Web Steel Joists (OWSJs) are the smartest choice — and at Peel Welding & Fabrication, we handle every part of the job, from fabrication to field welding, right here across the GTA.
This guide breaks down what OWSJs are, why they dominate commercial construction in Ontario, and how to choose the right contractor for installation, reinforcement, and repair.
What Are Open Web Steel Joists (OWSJs)?
An Open Web Steel Joist is a lightweight, truss-like structural member made of steel chords connected by an open web of angled members. That open configuration is exactly where its name — and most of its advantages — come from.
Instead of a solid steel beam, you get an engineered framework that carries serious load over short and long spans while weighing a fraction of the equivalent solid section. OWSJs form the backbone of modern floor and roof systems in warehouses, big-box retail, manufacturing plants, schools, and mid-rise residential buildings throughout Ontario.
✅ At Peel Welding, every joist we fabricate and install meets the National Building Code of Canada (NBCC), the Ontario Building Code, and CAN/CSA S-16 structural steel requirements.
Why Builders Across Ontario Choose OWSJs
There’s a reason contractors, engineers, and developers in Mississauga, Brampton, Toronto, and beyond keep specifying open web steel joists:
OWSJs support heavy loads across long spans while keeping dead load low — meaning lighter supporting structures, smaller footings, and lower overall material costs.
The open web lets you route mechanical, electrical, and plumbing (MEP) systems straight through the joist cavities — no bulky drop ceilings, reduced building height, and a cleaner finished space.
OWSJs arrive prefabricated and ready to install, speeding up framing on commercial and industrial sites across the GTA.
Compared to solid steel beams, OWSJs deliver a more economical structural system for non-residential floor and roof assemblies — without sacrificing code compliance.
From warehouses and distribution centres to schools, offices, and multi-unit residential mid-rises, OWSJs adapt to a huge range of Ontario projects.
OWSJ Reinforcement: Add Capacity Without Full Replacement
One of the most common questions we get from building owners across Ontario is:
“My structure needs to carry more load — do I have to rebuild?”
Usually, the answer is no.
OWSJ reinforcement welding is a code-compliant way to increase the load capacity of existing joists — for example, when adding rooftop HVAC units, solar arrays, mezzanines, or heavier storage racking. Reinforcing existing joists instead of replacing the entire structural system delivers substantial savings and far less downtime, which is critical for occupied commercial facilities in Mississauga, Brampton, and the wider GTA.
Before any reinforcement work, our CWB-certified team performs an on-site assessment to identify corrosion, overloading, improper past modifications, or inadequate connections — and we hand your structural engineer the detailed findings they need to sign off. Not sure whether your structure needs reinforcement or a full welding service repair? Our team can assess it on-site.
Our Open Web Steel Joist Services in Ontario
At Peel Welding & Fabrication, we handle the full lifecycle of OWSJ work:
| ✓ OWSJ Installation — Complete new-build joist installation with precise placement and Ontario Building Code–compliant connections. |
| ✓ OWSJ Reinforcement & Load Upgrade — Cost-effective capacity upgrades for existing commercial and industrial structures. |
| ✓ OWSJ Fabrication & Custom Manufacturing — Standard joists, joist girders, gable joists, and specialty configurations built to your engineer’s stamped drawings. |
| ✓ OWSJ Repair & Field Welding — On-site repairs in active buildings, warehouses, and job sites with minimal disruption. Also available through our Mobile Welding Services. |
| ✓ OWSJ Inspection & Assessment — Certified condition assessments to support engineering decisions. |
| ✓ Joist Girder & Steel Deck Integration — Coordinated installation of primary framing and steel deck for a faster, cleaner build. |
👉 See full details on our Open Web Steel Joist service page, or browse our full range of welding & fabrication services.
Why CWB Certification Matters for Your OWSJ Project
Structural steel welding isn’t a place to cut corners. When joists carry the roof over your warehouse or the floor of an occupied building, the welds holding them together need to be inspectable, repeatable, and code-compliant.
Our welders hold certification through the Canadian Welding Bureau (CWB) under CSA W47.1 and W59 standards — the benchmark for structural welding quality in Canada. That certification means:
Serving Contractors & Developers Across the GTA and Ontario
Peel Welding & Fabrication is a Mississauga-based, CWB-certified welding and fabrication company. From our shop on Shawson Drive, we deliver OWSJ solutions to projects throughout:
Whether you’re a general contractor coordinating a new commercial build, a developer upgrading an existing facility, or a building owner facing an urgent joist repair, our team brings the equipment, certification, and local responsiveness your project needs. Take a look at our completed project portfolio or learn more about our team.
Frequently Asked Questions
Q: What’s the difference between an OWSJ and a steel beam?
A solid steel beam is a single rolled section; an open web steel joist is a lighter truss-like assembly of chords and web members. OWSJs offer a better strength-to-weight ratio and let you run MEP services through the open web.
Q: Can you reinforce existing joists instead of replacing them?
In most cases, yes. OWSJ reinforcement welding is a common, code-compliant way to add load capacity for new rooftop equipment, mezzanines, or heavier loads — at a fraction of the cost of full replacement.
Q: Do you serve my city in Ontario?
We’re based in Mississauga and serve the entire GTA — Brampton, Toronto, Vaughan, Oakville, Markham, Hamilton, and surrounding areas. Contact us to confirm coverage for your site.
Q: Are your welders certified?
Yes. Our team is CWB-certified under CSA W47.1 and W59, and all work meets NBCC, Ontario Building Code, and CAN/CSA S-16 standards.
Get a Free OWSJ Quote in Ontario
Planning a project that calls for open web steel joists? Whether it’s new installation, reinforcement, custom fabrication, or emergency repair, Peel Welding & Fabrication is ready to help.
| 📞 +1 (905) 330-0603 | 📍 Unit 14 – 6315 Shawson Dr., Mississauga, ON, L5T 1J2 |
📧 peelwelding@gmail.com
Found us through Google? We’d appreciate a review on our Google Business Profile — it helps other Ontario builders find reliable, CWB-certified OWSJ services.