On-Site Welding Service in Toronto
Structural work doesn't always happen in a shop. When steel needs to be welded where it stands in your warehouse, on your job site, or at your facility, you need a certified mobile welding crew that shows up equipped and executes to code. CanaStruct Inc delivers professional on-site welding across Toronto and the GTA, supporting structural steel modification, new construction framing, mezzanine builds, and custom component fabrication without disrupting your operations.
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What Is On-Site Welding?
On-site welding also called field welding or mobile welding is structural or fabrication welding performed at the project location rather than in a fabrication shop. It's required when steel members are too large or already installed to transport, when connection geometry requires field-fit welding, or when modifications need to be made to existing structural steel in place.
On-site welding differs from shop welding in one important way: the welder works in real-world conditions variable temperatures, limited access, and an active job site rather than a controlled shop environment. That demands more skill, not less.
Key applications of on-site welding in construction and facilities include:
Structural steel modification: cutting, reinforcing, or connecting existing structural steel members
Steel beam installation: welding primary beams to columns or connection plates in place
On-site component fabrication: fabricating brackets, plates, stiffeners, or custom steel components directly on site
Warehouse mezzanine construction: moment connections, base plates, and critical structural joints in mezzanine systems
Framing connection welds: structural connections in commercial framing that can't be achieved with standard hardware
All structural welding on construction projects in Ontario must be performed by CWB-certified welders. CanaStruct meets this requirement — our welders hold current CWB certification and perform work to the standards specified by the engineer of record.
Types of On-Site Welding Services
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Structural Steel Modification
Existing buildings sometimes need their structural steel modified beams extended, openings cut, connections added, or reinforcement installed to accommodate new loads or layout changes. CanaStruct performs structural steel modification in active commercial, industrial, and warehouse facilities across the GTA.
This work requires careful coordination with the building's structural engineer, who must approve all modifications to load-carrying members. CanaStruct works directly with engineers of record, executes to approved drawings, and ensures all welds are performed and inspected to the required standards.
Structural steel modification is precise, consequential work. It requires certified welders who understand load paths CanaStruct delivers both.
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Steel Beam Installation with Field Welding
Steel beam installation in existing buildings often requires field welding particularly when new beams are being connected to existing columns, when moment connections are required, or when connection geometry doesn't lend itself to standard bolted hardware.
CanaStruct performs steel beam installation with in-house field welding capability. Our crews set beams, verify alignment and level, perform connection welds to the structural drawings, and coordinate inspection requirements with the engineer of record.
This is common in commercial retrofits, mezzanine additions, and structural opening creation work that requires both framing competence and certified welding in a single crew.
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Warehouse Mezzanine Construction Welding
Warehouse and industrial mezzanines often include structural connections that require field welding column base plates welded to anchor systems, moment connections between columns and beams, and custom connection details that the structural engineer has specified as welded rather than bolted.
CanaStruct's on-site welding capability is integral to our mezzanine framing scope. When the structural drawings call for field welds, our certified welders execute them on the same timeline, by the same crew, without scheduling a separate welding subcontractor.
This matters on mezzanine projects because welded connections are often on the critical path. Having welding in-house keeps your project moving.
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On-Site Component Fabrication
Not every steel component arrives from the shop perfectly fitted. Plates need trimming, brackets need adjustment, stiffeners need to be fabricated to match field conditions. CanaStruct's mobile welding crew performs on-site component fabrication cutting, fitting, and welding custom steel elements directly at your project location.
This service is especially valuable on renovation and retrofit projects where existing conditions don't always match drawing assumptions, and field-fabricated components are the most efficient solution.
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Our Process
Step 1 — Scope & Consultation
We assess your welding scope, connection types, structural specs, site conditions, and project timeline to quote accurately and assign the right certified crew for your project.
Step 2 — Drawings & Site Review
We review your structural or fabrication drawings and assess site access, existing conditions, and any constraints that affect welding scope, sequencing, or crew setup requirements.
Step 3 — Clear Written Estimate
You receive a detailed, itemized written estimate covering labour, equipment, materials, and timeline — with all assumptions documented upfront so there are zero surprises on site.
Step 4 — Schedule & Coordination
We lock in the project schedule, align with your GC or project manager, and coordinate with the engineer of record on inspection requirements and site access protocols.
Step 5 — Certified Weld Execution
Our CWB-certified welders mobilize on schedule, set up safely, perform precise fit-up, and execute every weld to specification while keeping a clean, organized work area throughout.
Step 6 — Weld Quality Inspection
Our welders and site supervisor visually inspect every weld before calling for an engineer or third-party review — we hold our own work to the required standard first.
Step 7 — Closeout & Documentation
Welds are inspected, approved, and fully documented. We close out our scope, provide all required paperwork, and leave the site clean and ready for your next project phase.
On-Site Welding vs. Alternatives
On-Site Welding vs. Shop Fabrication with Bolted Connections
For most structural connections, the choice between field welding and shop-fabricated bolted connections comes down to engineering requirements, project sequencing, and practicality.
Bolted connections using shop-fabricated components are faster to assemble in the field and don't require certified welders for installation. They're the preferred approach when connections can be designed with standard hardware and when shop fabrication timelines align with the project schedule.
Field welding is required or preferred when: connection geometry demands welded joints, when modifications to existing steel need to be made in place, when moment connections are specified by the engineer, or when site conditions make bolted connection assembly difficult.
Cost: Shop-fabricated bolted connections are generally lower in field labour cost when the design accommodates them. Field welding carries higher on-site labour cost but eliminates the need for precise shop fabrication and allows more flexibility in field conditions.
Durability: Both properly designed and executed bolted and welded connections provide excellent long-term structural performance. The engineer of record specifies which connection type is appropriate for each application.
Performance: Welded moment connections offer higher rigidity than most bolted alternatives and are required in certain structural applications — particularly in seismic zones or high-load situations.
Flexibility: On-site welding provides maximum flexibility for modifications, renovations, and field-condition adjustments. When something doesn't fit as drawn, a qualified mobile welding crew can solve problems that bolted connections can't.
Why Choose CanaStruct Inc for On-Site Welding in Toronto
CWB-Certified Welders: Every structural weld CanaStruct performs is executed by CWB-certified welders. This is a non-negotiable standard on all our projects.
Fully Licensed and Insured: CanaStruct carries full commercial liability insurance and WSIB coverage on all on-site welding work. You're protected from day one.
Integrated Framing and Welding Capability: Unlike standalone mobile welding services, CanaStruct delivers welding as part of a full commercial framing capability. You get structural expertise at every level of the project.
Code-Compliant Execution: We work to the standards specified by the engineer of record and ensure all welding documentation meets inspection requirements across Toronto and GTA municipalities.
Experienced Structural Team: Our crew has performed on-site welding on mezzanines, commercial retrofits, steel beam installations, and structural modifications across the GTA. This experience matters in the field, where conditions rarely match drawings exactly.
Reliable Scheduling: On-site welding is often on the critical path. CanaStruct shows up when scheduled and completes work within committed timelines. When field conditions require problem-solving, we solve them quickly.
Transparent Pricing: You receive a detailed written estimate before any work begins. No surprise charges for equipment, setup, or additional time without prior approval.
Local Credibility: CanaStruct has completed on-site welding work for contractors and facility owners across Toronto, Mississauga, Markham, Scarborough, Richmond Hill, Oakville, and beyond. We know the local construction environment and the people in it.
Service Areas we Serve
CanaStruct Inc provides on-site welding services throughout the Greater Toronto Area. Our mobile welding crews are available in:
Toronto (all commercial and industrial zones)
East York
Etobicoke
North York
Scarborough
Richmond Hill
Markham
Caledon
Mississauga
Oakville
Whether your project is a warehouse modification in Etobicoke, a mezzanine build in Markham, or a commercial framing project in downtown Toronto, CanaStruct's mobile welding crew can be on site.
Frequently Asked Questions
Do I need CWB-certified welders for on-site structural welding in Ontario?
Yes. Structural welding on permitted construction projects in Ontario must be performed by CWB (Canadian Welding Bureau) certified welders. CanaStruct's welders hold current CWB certification, and all structural field welds are performed and documented to the standards specified by the engineer of record.
What is the difference between on-site welding and shop fabrication?
Shop fabrication involves welding or assembling steel components in a controlled factory environment before delivery to site. On-site welding is performed in the field after steel is positioned or installed. Shop fabrication is preferred when connections can be standardized and delivered fully prepared. On-site welding is required when connections must be made in place, when modifications to existing steel are needed, or when field conditions require custom work.
What types of structural steel modification does CanaStruct perform?
CanaStruct performs a range of structural steel modifications including beam extensions, connection reinforcement, new connection points added to existing columns or beams, structural opening creation, and load-path modifications designed and approved by a structural engineer. All modifications are performed to engineer-approved drawings.
How much does on-site welding cost in Toronto?
On-site welding costs depend on the number and type of welds required, site access conditions, the structural specification, and whether the work is part of a broader framing scope. CanaStruct provides detailed written estimates after reviewing drawings and visiting the site. Contact us for pricing on your specific project.
What is mobile welding and how does it differ from on-site welding?
Mobile welding and on-site welding refer to the same service — welding performed at the client's location using portable equipment. The terms are interchangeable. CanaStruct's mobile welding crews serve commercial construction sites, industrial facilities, and warehouses across the GTA.
Can CanaStruct perform on-site welding as part of a mezzanine project?
Yes — this is one of CanaStruct's core applications. Mezzanine construction often requires structural field welds for column base plates, moment connections, and custom connection details. CanaStruct's certified welders are part of our mezzanine framing crews, eliminating the need to schedule a separate welding subcontractor.
What welding processes does CanaStruct use for structural work?
CanaStruct's field welders are equipped for FCAW (Flux-Cored Arc Welding) and SMAW (Shielded Metal Arc Welding), which cover the majority of structural steel welding applications in Ontario commercial and industrial construction. The appropriate process is specified by the structural engineer and followed exactly.
Can on-site welding be performed in active warehouses or occupied buildings?
Yes, with proper safety measures. CanaStruct sets up welding screens, ensures adequate ventilation, and coordinates with facility management to perform welding safely in active environments. We have extensive experience working in occupied warehouses and industrial facilities across Toronto and the GTA.
Does CanaStruct handle both framing and on-site welding, or only welding?
CanaStruct specializes in both commercial structural framing and on-site welding — the two services are integrated within our crews. This is a significant advantage on projects that require both framing and field welds, as it eliminates scheduling gaps between trades and gives you a single point of accountability for the full structural scope.