Choosing a commercial interlocking contractor is not the same decision as picking someone for a driveway. The contract is bigger. The liability is real. And more than one person usually has to sign off before a shovel touches the ground. If you manage a property, sit on a board, or are building a shortlist before an RFP goes out, here is what actually separates a contractor worth hiring from one that will cost you later.
In short, a good commercial interlocking contractor comes with verified WSIB coverage, liability insurance that meets commercial minimums, references from similar commercial projects, a clear written proposal that lets you compare scope, and real experience managing site access, traffic, and construction phasing. The rest of this guide walks through how to check each one before you sign anything.
Key Takeaways
Ask for a current WSIB clearance certificate you can verify yourself, not a verbal promise.
Confirm liability insurance meets commercial minimums, and ask to be named as an additional insured.
Request three or more references tied to similar commercial work, with contact information.
Compare itemized bids, not bottom line numbers.
Watch for bids missing a site visit, a base specification, or a named project contact.
A site assessment, not a phone estimate, should be the first real step.
Commercial Interlocking Contractor Checklist
Everything in this guide comes down to ten checks. Here they are in one place, so you can work through them with anyone you’re considering.
Current WSIB clearance certificate
Liability insurance meeting commercial minimums
Additional insured documentation
Three or more relevant commercial references
Recent, verifiable project photos
A site visit completed before quoting
Written excavation and base specifications
A fully itemized proposal
A clear change-order process
A dedicated project contact
Why Commercial Contractor Vetting Is Different From Hiring for a Driveway
A homeowner picking a driveway contractor makes one decision, for one property, with one person’s money on the line. Commercial work runs differently, and the difference shows up long before the crew arrives.
A residential driveway might run a few thousand dollars and take a few days. A plaza walkway, a condo courtyard, or a parking lot resurface can run into six figures, with a timeline stretching to weeks once phasing is involved.
The liability is different too. A trip-and-fall on a heaved paver in a parking lot can create liability concerns for the property owner or occupier, depending on the circumstances and applicable Ontario law, not just a cosmetic problem on the surface. Drainage failures carry similar weight. A driveway that pools water near a garage is an inconvenience. A commercial site that floods a loading dock or backs up into a mechanical room is a repair bill and a possible business interruption.
And the decision rarely rests with one person. A facilities director might run the search and build the shortlist, but a property manager, an ownership group, or a board still needs to approve it before a contract gets signed. If you’re comparing quotes for a home instead, our guide on choosing a residential interlocking contractor in the GTA covers that decision from the ground up. This piece is built for the commercial side.
| Factor | Residential | Commercial |
|---|---|---|
| Decision makers | Usually one person | Often several, sign-off required |
| Site access | Generally straightforward | Frequently restricted or scheduled |
| Traffic exposure | Low | Higher vehicle and pedestrian traffic |
| Scheduling | Flexible | Often phased around business hours |
| Drainage impact | Limited to the property | Can affect building operations |
| Proposal detail | Basic quote | Detailed, itemized scope |
| Project coordination | Simple | Requires more oversight |
Licensing, WSIB, and Insurance Minimums to Confirm
WSIB Clearance Certificate
Don’t take a contractor’s word for it. Ontario’s Workplace Safety and Insurance Board issues clearance certificates you can confirm directly through their online verification tool. If a company hesitates, or says their WSIB is “in progress,” treat that as a stop sign.
Liability Insurance
Commercial contracts across the GTA generally require liability coverage well above a typical residential policy. Get the certificate in writing, check that the policy dates are current, and ask to be named as an additional insured for the length of the project.
Hiring an improperly covered contractor can create additional risk for the property owner or manager, so WSIB status should be verified before work begins, not assumed.
What to Ask About Past Commercial Projects
References From Similar Work, Not Just Photos
Photos show you a finished product. They don’t show you how a company handled a live site, a tight schedule, or a call at 7am because water pooled near a tenant entrance overnight. Ask for three or more references from projects similar to yours, a parking lot, a plaza walkway, a condo common element, an institutional courtyard, whatever matches your scope. Get contact information, not just a name, and when you call, ask:
Was the project similar in size and use to yours?
Was it completed on schedule?
How did the contractor handle unexpected site conditions?
How responsive were they after the work was done?
Would they hire the same company again?
Verify Photos Match Real, Recent Work
A portfolio full of impressive images means little if you can’t confirm where or when the work happened. Ask which of their listed projects are local, recent, and verifiable, and don’t be shy about asking to drive by a completed site if it’s nearby. A contractor confident in their work will point you toward it, not around it.
In-House Crews or Subcontractors
Ask directly whether the crew on your job will be the contractor’s own employees or a subcontracted team, and whether that’s the same crew referenced in their case studies. A company that subcontracts everything with no direct oversight on site carries a different level of risk than one that runs its own crews start to finish.
Inno Interlocking has worked on plaza walkways, condo courtyards, and parking area projects across Markham, Vaughan, Richmond Hill, and the rest of the GTA. Whoever you’re considering, ask for that same kind of local, verifiable track record.
Comparing Bids: Apples to Apples Scope
The bottom line number on a bid tells you almost nothing on its own. Ask for an itemized breakdown so you can compare scope between contractors, not just price. Commercial jobs carry cost categories a residential quote never touches. Make sure each bid separates out:
Traffic control and staging costs for active sites
Permit fees where the municipality or property requires them
Temporary fencing and coordination with your own site security
Phasing costs if the work is split to keep part of the site open
If those line items are missing entirely, ask why before you assume the lower number is the better deal. And if a contractor won’t itemize at all, or hands you a single line with a total, that’s worth a direct question before you go any further.
Don’t compare bids like this:
Contractor A: $80,000 | Contractor B: $92,000 | Contractor C: $105,000
Compare them category by category instead:
Excavation → Base → Drainage → Pavers → Labour → Traffic control → Phasing → Cleanup → Warranty
Red Flags Specific to Commercial Bids
No written base specification. If a bid doesn’t say how deep the excavation goes or what base material is used, the contractor either hasn’t planned it or isn’t willing to put it on paper.
No site visit before the quote. Commercial sites have access constraints, drainage patterns, and traffic considerations that can’t be judged from a phone call or a set of photos. A quote built without walking the property is a guess.
No named contact for the length of the project. On a multi-week commercial job, you need one person accountable for updates and problems, not a rotating cast with no clear owner.
Won’t provide additional insured documentation. If a contractor resists naming your organization on their policy, that resistance tells you something about how they’d handle a real claim.
A vague or missing change order process. Ask upfront how the contractor handles conditions that differ from what was quoted, like unexpected soil or buried utilities. If there’s no clear answer, that’s where cost overruns start.
No commercial references, only residential examples. A contractor who’s great at driveways isn’t automatically equipped for a plaza or a condo common element. Ask specifically for commercial-scale work.
No warranty terms documented in writing. Important contractual terms like this should be in the agreement before you sign, not confirmed verbally after the fact.
Questions to Ask About Project Management and Site Access
Commercial sites don’t shut down for construction the way a driveway does. Tenants still need access. Deliveries still need to happen. Before you sign, get clear answers on:
How work will be sequenced around your business hours
Whether the crew can phase work to keep part of the site open
How access badges or security check-ins are handled, if your property requires them
Who the single point of contact is if something needs attention mid project
You don’t need a full project timeline breakdown at the bid stage. You need to know the contractor has actually thought about your operations, not just the paving.
Where to Start: Getting a Commercial Site Assessment
Every solid commercial interlocking job starts the same way: someone walks the property before a number gets written down. Soil conditions, drainage patterns, access points, existing utilities and catch basins, and how the space actually gets used all shape the base design and the bid. A phone quote skips all of that, and a bid built on assumptions tends to unravel once work begins.
A proper assessment covers the condition of existing surfaces, where water currently moves across the property, what access looks like for equipment and material delivery, and whether the project makes more sense as one continuous job or phased around your operations. That conversation is what a written proposal should be built on, not a guess based on square footage.
The right commercial interlocking contractor should be able to show you three things before work begins:
Relevant commercial experience
A site-specific proposal, not a generic one
A clear plan for operating around your property while work is underway
If you’re comparing contractors for a commercial property in the GTA, start with a site assessment, not a phone call.
Request a Commercial Site AssessmentFrequently Asked Questions
What should I look for in a commercial interlocking contractor?
Look for verified WSIB coverage and liability insurance, three or more references from similar commercial projects, a site visit completed before quoting, a clear written proposal you can compare against other bids, and a documented plan for managing access and traffic while the property stays operational.
How is commercial interlocking different from residential work?
Commercial sites carry heavier vehicle loads and more pedestrian traffic, and the approval process usually involves more than one decision maker rather than a single homeowner.
What size project actually needs a formal bid comparison?
Any project involving shared property, tenant access, or a contract value that needs sign off from more than one person, including plazas, parking areas, and condo common elements.
Is a WSIB clearance certificate the same as insurance?
No. WSIB clearance covers workplace injury. Liability insurance is separate and covers property damage or third party claims. Confirm both directly rather than assuming.
What does it mean to be named as an additional insured?
Your organization is added to the contractor’s liability policy for the length of the project, so a claim tied to the work is covered under their insurance rather than falling back on yours.
How many references should I request?
Three is a reasonable minimum, and they should come from projects similar in scope and type to yours.
Can commercial interlocking work be done without shutting down a business?
Often, yes. Many commercial jobs are phased so part of the site stays open while another section is under construction.
What happens if a contractor subcontracts part of the job?
That’s common on larger projects and isn’t a problem by itself. What matters is who takes responsibility if something goes wrong after installation.
Why do itemized bids matter more on commercial jobs?
A single bottom line number hides what’s included. Itemized bids let you compare scope and site logistics side by side, so a lower price doesn’t hide a smaller scope.
What’s the first step in hiring a commercial interlocking contractor?
Request a site assessment. A contractor who visits the property before quoting gives you a bid that reflects your site, not a guess based on square footage alone.