Flat Roofing 101: Pros & Cons, Repairs & More!

Whether you’re in the market for a new roof or need help with your current flat roof, you’ll want to read on. In this blog post, we will discuss everything you need to know about flat roofing: what it is, types of flat roofs, the pros and cons, and common repairs. By the end of this article, you should have a good understanding of your flat roof and what to do if you run into issues.

What is Flat Roofing?

Flat roofing may seem self-explanatory but there’s more than meets the eye. While flat roofs may appear to be completely flat when looking at them from the ground level, most of the time they are slightly pitched (5 to 15 degrees) so that water can drain off of them properly. In this guide, we will discuss the basics of flat roofing, including its types, materials used, and benefits.

Pros of Flat Roofing:

Easy maintenance & access:

Flat roofs are often easier and safer to maintain than sloped roofs. They simplify debris removal and regular inspections to keep seams and penetrations in good condition. This easy access allows for more efficient repairs and routine maintenance with less injury risk.

Additional space:

Flat roofs provide extra usable space for storage or mounting equipment like HVAC units. This extra space is valuable for both residential and commercial properties, offering flexibility in using the area above the building. Some people even use flat roofs as recreational spaces, like rooftop gardens or patios.

Reflective surfaces:

Flat roofs often use reflective materials to reduce energy bills by reflecting sunlight and minimizing heat absorption, which lowers cooling costs in summer. This makes flat roofs an eco-friendly option.

Aesthetics:

Some flat roofs are visually appealing and may not block scenic views, ideal for certain locations. They can be designed to complement modern architectural styles. “Green” flat roofs with gardens and plants create beautiful, sustainable spaces, improving air quality and offering natural insulation.

Cons of Flat Roofing:

Leaks:

The main downside of a flat roof is its higher risk of leaks due to fewer drainage paths. Regular inspections and timely repairs are necessary to prevent damage. Locating the source of a leak can be tricky because water can travel far between the roof and ceiling before dripping, leading to confusion. Proper sealing and maintenance can help, but they require consistent attention.

Snow and ice:

Flat roofs accumulate snow and ice more easily than sloped ones, which can lead to dangerous conditions and structural damage from the weight. This can also cause ice dams, blocking water drainage and increasing leak risks. Regular snow and ice removal and considering solutions like heating cables are crucial.

Heat loss:

Flat roofs are prone to heat loss since warm air escapes more easily, making them less energy-efficient than sloped roofs. This can lead to higher heating costs and reduced comfort in colder months. Investing in good insulation and ensuring roofing materials minimize thermal transfer can help. Regular checks for insulation issues are important for energy efficiency.

Types of Flat Roofing:

When it comes to flat roofing materials, several options are available, each with its pros and cons. Below, we’ll detail each one to help you make an informed decision based on cost, durability, maintenance, and weather resistance.

Built-Up Roof (BUR)

BUR is a common flat roofing system using layers of bitumen and fabric for a durable, waterproof surface.

Pros:

BUR systems are known for their longevity and excellent fire resistance. Composed of multiple layers, these roofs provide robust protection and can last 20 years or more with proper maintenance. Regular inspections can enhance their lifespan, making them cost-effective long-term.

Cons:

Improper installation can cause ponding water, leading to damage. Professional installation is crucial to prevent this.
These roofs require periodic gravel re-coating every year or two, based on sun exposure and weather conditions, to maintain their protective qualities.

Modified Bitumen

Modified Bitumen is asphalt mixed with polymers like SBS (Styrene Butadiene Styrene) or APP (Atactic Polypropylene).

Pros:

This versatile mix can be applied using cold adhesives, hot mopping, or torch-down methods. Cold adhesives make application easy and safe, while hot mopping uses heated asphalt for a strong bond. Torch-down uses an open flame for a robust seal.
With proper maintenance, these roofs can last 10 to 20 years. Regular checks, cleaning, and minor repairs can extend their life, keeping the underlying structure protected.

Cons:

It can be pricier than BUR (Built-Up Roofing) systems, but many find the extra cost worth it for the durability and performance.
Installation is more complex and may need specialized equipment and skilled labor, adding to the cost and effort.

Ethylene Propylene Diene Monomer - Flat Roofing

EPDM

Ethylene Propylene Diene Monomer is a synthetic rubber, usually black but also available in grey.

Pros:

Commonly used in commercial roofing for its low cost and easy installation, making it a budget-friendly choice without sacrificing quality.

Cons:

Prone to punctures if not properly installed and maintained, so hiring experienced professionals is crucial for durability.
It’s wise to explore and compare other options, as it may not suit all climates or building types.

TPO/PVC

Thermoplastic Polyolefin / Polyvinyl Chloride are the latest materials for residential flat roofs. They are similar, with TPO sheets being seamed and PVC seams welded.

Pros:

Non-flammable: These materials resist ignition, making them ideal where fire safety is crucial.
Long-lasting: Designed for extended use, they reduce the need for frequent replacements and ensure durability.

Cons:

TPO can be pricier than other flat roofing options due to its durability and energy efficiency, offering long-term savings despite the higher initial cost.
TPO roofs may be prone to punctures if not installed correctly, leading to leaks. Proper installation and regular maintenance are essential for longevity and performance.

Metal Roofs

Metal roofs can be installed on flat or low slope roofs and come in various materials like copper, zinc, steel, and aluminum. Their main drawback is that they tend to be hard and inflexible, making them more challenging for workers unfamiliar with them.

Pros:

Can last up to 50 years or more with proper maintenance, offering a long-term investment for property owners.
Provides excellent protection against extreme weather like hail, windstorms, heavy rain, and snow, making them popular in areas with severe weather.

Cons:

The initial installation cost can be higher compared to other flat roofing materials, but their longevity makes them cost-effective over time.
Regular inspections and maintenance are needed to prevent rust and corrosion from moisture and harsh conditions. Regular cleaning and repairs can help extend their lifespan.

Common Repairs for Flat Roofing:

There are a few common repairs that you may need to perform on your flat roof from time to time. Here are some of the most common:

Leak repair: Leaks are by far the most frequent issue encountered with flat roofs. When water penetrates the roofing material, it can lead to significant problems, not just for the roof but also for the interior of the building. Addressing leaks promptly is crucial because, if left untreated, they can result in extensive damage, promoting mold growth and compromising the structural integrity of the building below.

Patching and sealing: Another routine repair for flat roofs is patching and sealing any cracks or holes in the roofing material. Over time, weather conditions, temperature fluctuations, and physical wear and tear can lead to minor damages. By patching these vulnerabilities, homeowners can prevent water from seeping through, thereby averting further damage and extending the roof’s lifespan.

Recoating: Recoating is a preventative maintenance method used to enhance the longevity of flat roofs. It involves applying a fresh layer of protective coating over the existing roofing material. This process not only helps to prevent leaks by adding an extra waterproof barrier but also increases the overall durability of the roof. It is advisable to perform recoating every few years, depending on the roof’s exposure to the elements, to maintain its integrity and extend its service life.

Gutter cleaning: Flat roofs often have gutters attached to them to efficiently channel rainwater away from the structure. Keeping these gutters clean is essential in preventing clogs caused by leaves, twigs, and other debris. Clogged gutters can lead to water pooling on the roof, which increases the risk of leaks and water damage to the building below. Regular gutter cleaning helps ensure proper drainage and protects the roof and building.

Have a Flat Roof and Need Help, What’s Next?

If you’re looking for a new roof, be sure to consider all of your options before making a decision. Flat roofs have many benefits but also some drawbacks that should be taken into account when weighing whether or not they are right for you.

If you have a flat roof and need help with repairs, don’t hesitate to book a FREE Roof Inspection today! We are experts in all things flat roofing and would be happy to assist you with whatever needs you may have.