Best Roofing Materials for Flat Roofs

When it comes to protecting your building, choosing the right flat roof material is a critical decision. Flat roofs are common for commercial, industrial, and even some residential buildings in Quebec. However, their specific structure makes them more vulnerable to water accumulation and harsh weather if not properly covered. That’s why selecting the best roofing materials for flat roofs isn’t just about aesthetics or price — it’s about durability, performance, and long-term savings.

At Duro-Toit, we specialize in installing and maintaining all types of flat roofing systems. In this article, we’ll explore the most reliable flat roof materials available today, their pros and cons, and how to choose the right one for your project.

Why the Choice of Flat Roof Material Matters

Unlike sloped roofs that allow for natural water runoff, flat roofs tend to accumulate water and debris, increasing the risk of leaks and structural damage. This makes the selection of roofing materials for flat roofs particularly important. A poor choice can result in premature wear, increased energy costs, and frequent repairs.

The ideal flat roof material should offer:

Excellent waterproofing properties
UV resistance and temperature tolerance
Longevity and low maintenance
Compatibility with insulation and underlayment
Cost-efficiency for both installation and lifecycle

Let’s explore the most popular and effective materials for flat roofing on the market today.

1. Elastomeric Membrane Roofing (Torch-On Roofing)

Elastomeric membranes, often referred to as torch-on roofing, are a popular flat roof material in Canada, especially in Quebec, due to their excellent performance in extreme weather conditions.

Pros:

Highly durable, with a lifespan of 25 to 35 years
Excellent waterproofing thanks to its two-layer system (base + cap sheet)
UV resistant and handles freeze-thaw cycles well
Low maintenance once properly installed
Strong adhesion due to heat-welded installation

Cons:

Requires professional installation with a propane torch, which can pose fire risks
Higher initial cost than single-ply membranes
Not as eco-friendly as some newer options
Installation can be weather-dependent

Best for: Commercial and residential flat roofs in regions with significant temperature fluctuations (like Quebec). Ideal for owners who want a long-lasting and low-maintenance flat roof material with proven performance.

2. EPDM (Ethylene Propylene Diene Monomer)

EPDM is a synthetic rubber membrane widely used for flat roofs in North America.

Pros:

Extremely durable with a lifespan of 25–30 years
Easy to install and repair
Lightweight and flexible
Resistant to UV rays and ozone

Cons:

Aesthetic appearance (black rubber finish) may not appeal to all
Can shrink over time if poorly installed
More prone to punctures compared to some alternatives

Best for: Commercial buildings and low-slope roofs with minimal foot traffic.

3. TPO (Thermoplastic Polyolefin)

TPO is a single-ply roofing membrane that’s quickly gaining popularity as a flat roof material.

Pros:

White surface reflects sunlight, reducing cooling costs
Resistant to chemicals and algae
Welded seams improve waterproofing
Environmentally friendly and recyclable

Cons:

Lifespan can vary depending on manufacturer
May require professional installation for optimal results

Best for: Energy-efficient buildings and commercial facilities.

4. PVC (Polyvinyl Chloride)

PVC roofing membranes are similar to TPO but offer slightly different properties.

Pros:

Highly durable and resistant to fire and chemicals
Reinforced seams reduce risk of leaks
Flexible even in cold climates like Quebec

Cons:

Higher cost than EPDM or TPO
Can become brittle over time with UV exposure

Best for: Restaurants, manufacturing plants, or any building with chemical exposure or grease discharge.

5. Modified Bitumen Roofing (Mod-Bit)

Modified bitumen is an asphalt-based flat roofing system reinforced with fiberglass or polyester.

Pros:

Proven waterproofing performance
Multiple installation methods (torched, cold-applied, or self-adhered)
Affordable and widely available

Cons:

Installation can be labour-intensive
UV protection varies by top layer
Seams may degrade faster than single-ply systems

Best for: Residential flat roofs and budget-conscious commercial properties.

Bonus: Flat Roof Underlayment Options

While the flat roof material is the outermost layer, the underlayment plays a key role in durability. Options include:

Synthetic underlayment: Lightweight, resistant to water and tears.
Peel-and-stick membranes: Ideal for extra waterproofing under critical zones.
Asphalt-saturated felt: Traditional option, though less durable than modern synthetics.

At Les Couvreurs Duro-Toit, we always recommend pairing your roofing materials for flat roofs with the right underlayment to extend the system’s lifespan.

What Is the Best Roofing Material for a Flat Roof?

There’s no universal answer — it depends on your building type, budget, climate, and desired maintenance level.

Here are a few scenarios:

For energy efficiency: TPO or white PVC.
For affordability: EPDM or modified bitumen.
For extreme durability: Elastomeric membrane, PVC, or BUR.
For residential use: Modified bitumen, self-adhered membranes, or elastomeric membrane for longer lifespan and resistance to harsh weather.

Brands also matter. For instance, premium membrane systems (like Soprema) offer warranties and tested performance.

Get the Best Flat Roof Materials Installed by Professionals

Choosing the right flat roof material isn’t something to take lightly. With decades of experience serving Montreal and surrounding areas, our flat roof’s roofers helps you select and install the most suitable roofing materials for roofs, ensuring optimal durability and weather resistance.

Whether you’re building new or replacing an aging roof, contact our team for a personalized assessment. We offer: