Flat Roofing 101: A Comprehensive Guide to Understanding Flat Roofs
10 mins read

Flat Roofing 101: A Comprehensive Guide to Understanding Flat Roofs

What is Flat Roofing?

In the architectural world, flat roofing has evolved dramatically over the years. It is regarded as a practical and stylistically appealing option and is significant in contemporary construction designs. In this extensive guide, we explore the details of flat roofs, shedding light on their types, benefits, and essential maintenance tips. Traditionally, a flat roof has a pitch not exceeding 10 degrees to the horizontal. Despite the name, it’s not perfectly flat; it has a slight slope to facilitate water runoff.

A Deep Dive into Flat Roofing Systems: BUR, Modified Bitumen, and EPDM

As you plan your building project in the heart of Ottawa, Canada, it’s essential to understand your choices concerning flat roofing systems. They serve as the critical barrier protecting your investment from the elements. Each method has distinct attributes; your choice depends on your needs and local weather conditions. We’ll guide you through the intricate details of Built-Up Roofing (BUR), Modified Bitumen Roofing, and EPDM Rubber Roofing.

Built-Up Roofing

Built-Up Roofing (BUR), a classic and time-tested solution, has been safeguarding buildings for over a century. As its name suggests, this roofing system is built up through several alternating layers of bitumen (asphalt or coal tar) and reinforcing fabrics, creating a robust membrane. The topmost layer is typically finished with a surface treatment such as gravel or a reflective coating.

So, why might BUR be the right choice for your Ottawa building? Here’s why:

  • Durability: BUR systems are known for their robustness. The multiple layers provide a thick surface that withstands harsh weather and mechanical damage, serving well in Ottawa’s varying climate.
  • Waterproofing: BUR’s exceptional waterproofing abilities ensure your building stays dry and secure even during heavy rain or snow, which Ottawa frequently experiences.
  • Thermal Performance: BUR offers good insulation, helping maintain indoor temperatures and reduce energy costs.

However, installation can be labor-intensive and time-consuming. Proper ventilation is crucial during installation due to the use of hot bitumen.

Modified Bitumen Roofing

Modified Bitumen Roofing is the result of technological advancements aiming to combine BUR’s robustness with easier installation. This system utilizes bitumen modified with additives like atactic polypropylene (APP) or styrene-butadiene-styrene (SBS), which improve flexibility and strength.

Why consider Modified Bitumen Roofing for your Ottawa property?

  • Versatility: This system adapts to various building structures and designs, making it an ideal choice for commercial and residential properties.
  • Durability: Adding fiberglass or polyester layers enhances puncture resistance and longevity.
  • Easy Installation: Modified bitumen can be applied using several methods, including torch application, cold adhesives, or self-adhesive sheets, providing installation flexibility.

Be aware, though, that similar to BUR, installation can emit unpleasant odors and requires professional handling.

EPDM Rubber Roofing

EPDM (Ethylene Propylene Diene Monomer) roofing, often called rubber roofing, is a single-ply membrane known for its impressive durability and versatility. This synthetic rubber withstands the elements exceptionally well, making it suitable for Ottawa’s variable climate.

The perks of choosing EPDM for your Ottawa building include:

  • Weather Resistance: EPDM resists damage from UV rays, extreme temperatures, wind, and precipitation, making it ideal for Ottawa’s diverse weather conditions.
  • Durability: This roofing system is highly resistant to tears and leaks, offering a long lifespan.
  • Eco-friendly: EPDM is recyclable, and its light color options can reflect heat, reducing energy usage.

However, it’s worth noting that EPDM installation requires precision. Missteps could lead to leaks or reduced lifespan.

Exploring the Benefits of Flat Roofing

As you navigate the world of architectural design, you’ll encounter various roofing options, each offering unique features. However, flat roofing stands apart due to its distinct advantages, making it a compelling choice for many homeowners and architects alike. Let’s dive into the benefits of flat roofing, examining its versatility, ease of maintenance, cost-effectiveness, and aesthetic appeal.


The primary draw of flat roofing lies in its unmatched versatility. Unlike sloped roofs, flat roofs provide an extra layer of usable space, granting opportunities for numerous exciting applications.

Imagine transforming your rooftop into a lush rooftop garden, contributing to urban greening while offering a relaxing retreat. Or perhaps you envision an outdoor lounge area for social gatherings where you can unwind under the stars. For city buildings, this space can even accommodate HVAC units, keeping them out of sight and freeing up ground space.

The possibilities are boundless with the versatility that flat roofs provide.

Ease of Maintenance

The accessibility of flat roofs also translates to simpler and safer maintenance. In contrast to sloped roofs, where height and incline can complicate routine tasks, flat roofs are easily navigable.

Routine tasks such as gutter cleaning, debris removal, and inspection for damage become much less daunting when you don’t have to navigate steep slopes. Consequently, you’re more likely to keep up with regular maintenance, extending the life of your roof. And when repairs are needed, technicians can accomplish them with ease, making the process quicker and less disruptive for you.


When considering any major building component, cost plays a significant role. Fortunately, flat roofing systems score high in cost-effectiveness. The installation process of a flat roof typically requires less time and materials than a sloped roof, translating to lower labor costs.

In addition, the simplicity of design and accessibility of flat roofs often means that repairs and replacements are less expensive. Given the significant potential savings, it’s easy to see why many view flat roofing as a financially savvy choice.


Last but not least, flat roofs offer a unique aesthetic appeal. Embodying modern and minimalist design principles, they provide a sleek look that complements contemporary architectural styles.

Flat roofs contribute to a clean, streamlined profile that can make buildings appear more spacious and open. Moreover, if you choose to leverage your flat roof as a living space or garden, it can further enhance your property’s visual appeal, serving as a stunning design feature.

Key Maintenance Tips for Flat Roofs: Ensuring Longevity and Performance

While flat roofs provide many benefits, it’s important to remember that, like all aspects of a building, they need regular maintenance to remain in optimal condition. Carefully maintained, a flat roof can continue to protect and enhance your property for many years. We’ll guide you through essential maintenance tips for flat roofs, focusing on regular inspections, timely repairs, and the value of professional services.

Regular Inspections

Firstly, conducting routine inspections is a vital practice for ensuring the longevity of your flat roof. These inspections allow you to detect potential issues at their earliest stages, preventing minor problems from escalating into significant damage.

Make a habit of visually inspecting your flat roof, ideally twice a year and after any severe weather conditions. As you examine the roof, look for signs of damage, such as cracks, blisters, or punctures in the roof’s membrane. Additionally, keep an eye out for pooling water – as flat roofs should have a slight slope to allow for water runoff and any areas where water gathers may indicate a problem.

Timely Repairs

Even with meticulous maintenance, you’ll likely encounter a few problems with your flat roof over its lifetime. When you notice any issues – no matter how small – it’s crucial to address them promptly. Ignoring a seemingly minor issue like a small leak can lead to more significant damage, potentially compromising the structure of your roof and building.

Performing timely repairs safeguards your flat roof’s integrity and can save you from costly replacements. Always remember: acting proactively can be a game-changer regarding roof maintenance.

Professional Services

While some simple maintenance tasks can be performed DIY-style, hiring professional services for inspections and repairs is often the wiser choice. Trained roofing experts have the knowledge, experience, and tools to do a thorough job. They can spot subtle signs of damage that may be easy to miss for an untrained eye and implement effective, long-lasting solutions.

Moreover, professional roofers understand the safety measures necessary for roof work, protecting you from potential hazards. However, it may seem like an extra expense. Consider professional services as an investment into your roof’s longevity and performance.


Flat roofing offers a world of possibilities: versatility, cost-effectiveness, ease of maintenance, and modern aesthetics. From Built-Up to Modified Bitumen and EPDM Rubber Roofing, your choice can meet your needs in Ottawa, Canada. However, expert, professional maintenance is the key to unlocking its full potential.

Protecting your investment through regular inspections and timely repairs ensures your roof’s longevity and performance, offering a safer, more secure home or commercial space. Yet, finding your way in this realm can be challenging.

That’s where roofing contractors come in. Their expertise can transform your roofing journey, guiding you to make the right choice, aiding in installation, and ensuring dedicated maintenance for your peace of mind.

Discover the benefits of flat roofing today and safeguard your property with the best. Your journey toward a robust, stylish, and efficient flat roof starts here.