Ottawa has no shortage of interlock contractors. Finding one is easy. Finding a good one takes a bit more work – but the difference between a well-installed interlock driveway and a poorly installed one is the difference between a 30-year investment and a problem you’re dealing with in three years.
Here’s what to look for, what to ask, and what to walk away from.
Start with the Basics: Licensing and Insurance
Before anything else, confirm the contractor carries:
- WSIB (Workplace Safety and Insurance Board) coverage: Required for contractors with employees working in Ontario. If a worker is injured on your property and the contractor doesn’t have WSIB, you could be held liable. Ask for their WSIB clearance certificate – any legitimate contractor will provide it without hesitation.
- General liability insurance: Minimum $2 million coverage is standard. This protects your property if something goes wrong during the project. Ask for a certificate of insurance naming you as additional insured for the duration of the project.
A contractor who can’t or won’t provide these documents is not worth your time regardless of price.
10 Questions to Ask Any Ottawa Interlock Contractor
- What base depth are you specifying for this project? The right answer for a driveway is a minimum 8 – 10 inches of compacted granular base. For a patio, 6 – 8 inches. A contractor who doesn’t know or can’t answer this is a red flag.
- Will you include polymeric sand in the quote? Should always be included. Regular sand washes out and allows weeds.
- What edge restraints do you use? Should be heavy-duty plastic or aluminum edging with spikes, not just the border stones themselves.
- Do you offer a workmanship warranty? How long? One to two years is standard; some contractors offer more. Get it in writing.
- How long have you been doing interlock work in Ottawa specifically? Ottawa’s clay soil and freeze-thaw conditions require experience. Someone who learned their trade in a different climate may not account for local conditions correctly.
- Can you provide references from projects completed in the last two years? Not a portfolio on their website – actual references you can call or visit.
- What brand(s) of interlock stone do you work with? Established brands like Techo-Bloc and Permacon come with manufacturer warranties. Generic or unknown-origin stone doesn’t.
- Who will be on-site doing the work – your own crew or subcontractors? Not always a dealbreaker, but you want to know who’s actually doing the installation.
- How do you handle changes or unforeseen site conditions? Listen for a clear process: written change orders, client approval before proceeding. Vague answers here lead to disputes later.
- What’s your timeline and what are the payment terms? Legitimate contractors don’t ask for large deposits upfront. A typical structure is a small deposit to secure the schedule, progress payment mid-project, and final payment on completion.
Red Flags to Walk Away From
- Unusually low quotes: If one quote is dramatically lower than the others, something is being cut – usually base depth, material quality, or both. You will pay for it later.
- Cash-only or large upfront deposit: Not a professional business practice.
- No written contract or vague scope: Every detail – base depth, stone brand, pattern, edge restraints, polymeric sand, warranty – should be in the written quote.
- Pressure to decide immediately: A good contractor doesn’t need to pressure you.
- No verifiable reviews or references: Online reviews on Google, Homestars, or similar platforms matter. Zero reviews on a contractor claiming years of experience is a red flag.
- Door-to-door solicitation: “We have leftover materials from a nearby job” is a classic setup for low-quality quick work.
How to Compare Quotes Accurately
Get a minimum of three written quotes. When comparing them, make sure you’re comparing the same scope:
- Same base depth specified?
- Same stone brand or comparable quality?
- Polymeric sand included in all quotes?
- Edge restraints included?
- Demolition and disposal of existing material included?
- Site cleanup and final compaction included?
A lower quote that omits base depth or polymeric sand isn’t cheaper – it’s a different, inferior product. You can’t compare them at face value.
Why Ottawa Experience Matters
Ottawa’s freeze-thaw cycle, clay-heavy soil, and spring drainage conditions create challenges that contractors from other regions may underestimate. An experienced Ottawa installer knows to specify deeper base depths than minimum standards, to ensure drainage slopes away from the house, and to choose stone products tested in Canadian climate conditions.
Ask directly: “How many interlock projects have you completed in Ottawa? Can you walk me through how you handle base preparation for our soil conditions?” The answer tells you a lot.
Frequently Asked Questions
Is the cheapest quote always the worst option?
Not always, but a dramatically lower quote almost always means something is being cut. Base depth is the most common area contractors economize on – it’s invisible once the job is done, and the consequences don’t show up until the first or second winter.
How do I verify a contractor’s WSIB coverage?
The WSIB offers a free online clearance certificate check at wsib.ca. You can verify a contractor’s standing directly. Ask for their WSIB account number and check it yourself before work starts.
Should I get a contract for a small project?
Yes. Even for a small walkway, a written scope of work protects both parties. It doesn’t need to be a lengthy legal document – a detailed written quote that both parties sign is sufficient.
Get Your Free Estimate Today
Looking for a trusted interlock contractor in Ottawa? Contact JAL Deck & Interlock for a free estimate. We carry full WSIB and liability coverage, offer written warranties, and have been serving Ottawa and surrounding areas including Stittsville, Carleton Place, Nepean, and Barrhaven for over two decades.