Flat Roof Estimate Calculator (Ontario)
Flat Roof Replacement Cost Calculator For Commercial & IndustrialUse our Flat Roof Cost Calculator to estimate commercial/industrial flat roof replacement costs in Ontario. Results are based on recent bids and completed projects across the GTA and surrounding regions. For a firm quote, send drawings or photos and we’ll verify access, insulation, and detailing.
Over the past few years, flat roofs have gained increased favor due to their contemporary aesthetic, straightforward installation, and repair convenience. The typical expense for replacing a flat roof ranges from $5 to $10 per square foot. The installation of a basic 1,600 square foot flat roof comes to $8,000 to $16,000, contingent upon the material of your preference.
How to Use the Flat Roof Calculator
1. Begin by measuring your property from one corner to the other. Enter those dimensions into the “Roof Size” fields
2. Enter the number of curbs, such as hatches, skylights, or HVACs. These features require specialized flashing work and will contribute to the overall cost for each unit. It’s crucial to include them in your calculations to obtain a more accurate estimate, as a professional contractor will certainly consider these features.
3. Select the desired insulation thickness.
4. Enter the number of tear-off layers.
5. Choose the level of job complexity. This might vary, but if your project involves multiple penetrations, curbs, roof-to-wall flashing, or challenging drainage, opt for the Medium or Difficult setting. Additionally, consider factors like the ease of roof access. If your contractor needs to hire police detail or if your roof is situated seven stories above the ground, expect an increase in costs.
6. Pick the roofing material you prefer. You can obtain a price estimate for your chosen material and then recalculate for a different one to make a comparison. Modified Bitumen or Torched Down 2-PLY roofing is a popular choice due to its cost-effectiveness, while TPO is the second most commonly used material for commercial flat roofs.
7. Indicate your geographical location. Prices can vary by as much as 30% if outside of the GTA location.
Understanding Your Price Estimate
You will receive three price estimates: LOW-END, MID-RANGE, and HIGH-END. These estimates are based on the average roofing costs and includes the following:
- All necessary materials
- Labor expenses
- Costs for tearing off the existing roof
- Disposal fees
- Building permits
- Profit and overhead charges
Next steps: If your flat roof estimate points to end-of-life or you’re planning an upgrade, book our commercial flat roof installation & replacement service. If you need to control leaks or extend roof life, our flat roof repairs and maintenance service is the right place to start.
FAQ
How accurate is this calculator?
It’s a budgetary tool based on recent bids and completed projects across Ontario. Access, story count, winter work and warranty terms can shift pricing by ~±30%.
What’s included in the estimate?
Materials, labour, insulation, tear-off and disposal, flashing around curbs/penetrations, typical permits, and standard overhead & profit.
Why does pricing vary outside the GTA?
Labour rates, travel time, access, and material logistics differ by region. We apply a regional multiplier for areas outside the GTA.
What affects “job complexity”?
Multiple penetrations, roof-to-wall details, difficult access, height, and drainage adjustments generally increase time and cost.
How do I get a firm quote?
Email drawings or roof photos, size, number of curbs, roof height/access notes, and preferred membrane to info@northcanroofing.com or call 416-456-0777.
Our Methodology
What’s included: materials, insulation, labour, tear-off, curbs/penetrations flashing, disposal, permits, standard overhead & profit.
Key drivers: roof size, number of curbs, insulation thickness, layers to remove, job complexity, material choice (Mod-Bit, EPDM, TPO, BUR), and location.
Typical range (Ontario): $9–$15/ft² with GTA as baseline; outside GTA can vary ~±30% due to labour/logistics.
Assumptions: normal access/hours, standard warranty details, no structural/deck replacement.
Accuracy: budgetary only; we confirm on site review or from drawings/photos.