How to compare multiple roofing quotes
Written by Marc D., GCT Expert Analyst · Updated February 2026 · 3 min read
Three quotes with very different prices does not mean three comparable offers. Here is the rigorous method to decide without making mistakes.
The three-quote trap
Québec homeowners are told: "always get three quotes." The advice is correct, but incomplete. Without an analysis framework, comparing three prices almost always leads to the cheapest one — which is rarely the best decision.
Here is the method our advisors use.
Step 1 — Put the quotes in the same format
Refuse verbal quotes. Demand in writing, for each contractor:
- Exact roof surface in sq ft
- Type and precise brand of materials
- Detail of underlayment and eave membrane
- List of accessories (vents, flashings, ridge)
- Tear-off and disposal terms
- Municipal permit included or not
- Execution timeline
- Payment terms
Step 2 — Analyze the scope of work
This is where multi-thousand-dollar gaps hide.
| Item | Quote A ($12,800) | Quote B ($10,400) | Quote C ($14,200) |
|---|---|---|---|
| Shingle | Architectural 30 yrs | Standard 25 yrs | Architectural 30 yrs |
| Eave membrane | 6 ft (3 courses) | 3 ft (1 course) | 6 ft + valleys |
| Underlayment | Synthetic | Felt 15# | Premium synthetic |
| New vents | 6 included | Not specified | 8 included |
| Damaged decking | 2 sheets included | Extra per sheet | 4 sheets included |
| Installation warranty | 10 yrs written | 2 yrs verbal | 15 yrs written |
| Permit | Included | Not included | Included |
The $3,800 gap between B and C does not reflect a higher margin — it reflects a fundamentally different product.
Step 3 — Verify warranties
Two warranties always coexist:
- Manufacturer's warranty on the material (often 25 to 50 years, but with conditions)
- Installation warranty on labour (the most important)
A written 10-year installation warranty is worth far more than a 50-year manufacturer warranty without an installation warranty.
Step 4 — Assess ventilation
A well-installed but poorly ventilated roof loses 30 to 40% of its lifespan. Check:
- Presence of soffit vents
- Roof vents or continuous ridge
- Calculation of the 1/300 ratio (1 sq ft of ventilation per 300 sq ft of ceiling)
If the contractor does not mention ventilation in the quote, ask why.
Step 5 — Verify the company itself
- Active RBQ licence in subcategory 4.2
- Valid $40,000 bond
- $2M civil liability insurance
- Civic address in Québec
- At least 3 recent references
Step 6 — Read the fine print
Words to look for:
- "Subject to inspection of the decking" → unpredictable costs
- "Depending on material availability" → uncertain timelines
- "Non-refundable deposit" → increased risk
- "Balance due on material delivery" → avoid
- "No warranty in case of frost" → exclusion to clarify
Suggested weighting table
| Criterion | Weight |
|---|---|
| RBQ compliance and insurance | 25% |
| Material quality | 20% |
| Written installation warranty | 20% |
| Detailed, clear scope | 15% |
| Reputation and references | 10% |
| Price | 10% |
Yes, price weighs only 10%. Because a bad choice costs 5 to 10 times more in future repairs.
FAQ — Quote comparison
How many quotes should be requested?
Three is the minimum, five is ideal for a project above $15,000.
What to do if one quote is significantly lower than the others?
Be wary. Ask the contractor to justify line by line. If exclusions do not surface, drop the quote.
Can you negotiate the price?
Yes, but on scope, not on margin. Ask what can be added at the same price rather than what can be removed.
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