Types of Flat Roofs | Pros and Cons of Flat Roofing System


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Flat roofs are popular with homeowners and businesses. These types of flat roofs are valued for their flexibility and the variety of roofing materials available when building them. However, the selection of different flat roof materials on the market can make decision-making difficult. Failure to choose the best one for your specific coverage needs can result in time-consuming renovations and costs that are well beyond your budget.

Types of Flat Roofs

types of flat roofs

There are three main types of flat roofs: embedded roof, rubber membrane, and modified bitumen.

Built-Up Roof (BUR)

Before introducing modified membrane and bitumen variants, this was one of the most common flat roofs. This cost-effective roof system consists of an underlay or two insulation panels and many intermediate mixtures of asphalt or tar alternating with a felt roof. The top layer of built-up roofs are made from several layers of rocks and are less likely to catch fire Longevity – Each layer of material you add to your built-up roof will extend its life by about five years. 

Rubber membrane

The rubber membrane roof consists of a sheet of synthetic rubber known as ethylene propylene diene monomer (EPDM). These easily recognizable roofs are weighted down, weighed from large river rock, or glued together during assembly.

Modified bitumen

Developed in the early 1960s, modified bitumen roofs are a lightweight alternative to embedded roofs. It’s a DIY-compatible system as it can be installed without a mess. Its single-layer roof adhesive is usually applied with a burner to optimally heat the back of the material and to fuse it with the base layer.

Pros and Cons of Flat Roofing System

types of flat roofs

Pros of Roofing System


The materials used for flat roofs are cheap, which makes them affordable. Labor costs are also lower as the installation is less complex.

Easy to install

As mentioned earlier, installing a flat roof is easy and takes less time than installing alternatives. And the repair is painless because it is fixed quickly.


In contrast to pitched roofs, flat roofs are available to be easily inspected for damage and leaks. You can also use the roof in various ways, such as B. to create a terrace, a garden, or for relaxation or entertainment, z. B. at parties or other gatherings. Flat roofs are also the best place to install solar panels.

Leave space for the HVAC units.

There is enough space on flat roofs to accommodate HVAC equipment, including commercial ones. It is safer to install the building’s HVAC system on a roof to prevent vandalism or damage.

Energy efficient

Flat roofs are more energy-efficient than pitched roofs because they have a membrane system on rigid insulation panels. The nonappearance of holes impedes the section of air.

Easy to clean

Since flat roofs are cheaper than other flat roof systems, they are easier to maintain. The ability to make all parts accessible for regular cleaning prevents mold, algae, stains, and deposits.

Cons of Flat Roofs

Less attractive

Flat roofs are not a style; they are a function. They come in nonpartisan shadings like dark, white, and dim. So if you are looking for design and looks, look elsewhere.

Drainage problems

Flat roofs are subject to drainage problems as water tends to pool. Unlike pitched roofs, which are equipped with tiles to drain away water, flat roofs have to watch for stagnant water, dirt, and clogged drains. Ask your flat roof contractor about additional mechanisms to ensure proper drainage.

It won’t belong

Flat roofs typically need to be replaced after 10-15 years, affecting your ability to sell a property if the buyer is aware of the limited lifespan.

Less stable

Flat-roof buildings are less stable because they do not have adequate drainage and cannot bear the weight of snow and rain. This can lead to leaks at the seams.

Rubber Coating

types of flat roofs

Pros of Rubber Coating (EPDM)


Epdm rubber is a lightweight covering system. It weighs less than 2 kg per square meter or 100 square meters.

Easy to install

EPDM rubber is easy to install as it does not require thermal welding or special tools. Also available in rolls such as TPO and PVC, making it easier to place on roof surfaces.

Life expectancy

The EPDM rubber roof system is expected to last 20 to 30 years, roughly the service life of asphalt shingles. For example, the Florida building code says these shingles cannot be used on roof slopes less than 17 percent, or 2 inches of vertical rise for every 12 inches horizontal.


EPDM is more elastic than some other flat roof materials like TPO, PVC, etc. The standard black material absorbs heat, and light-colored coatings (recommended in warm climates) add 30% or more to the cost.


EPDM rubber costs between $ 75 and $ 450 per square meter (100 square meters). It’s cheaper than most other flat roof systems.

Fire resistance

EPDM rubber is very fire resistant. They even make EPDM with flame retardants that help put out the flames.

Temperature fluctuations

Due to its elastic properties, EPDM rubber can withstand a wide range of temperatures. It can withstand temperatures as low as -60 ° F or as high as 300 ° F.

Increase the wind

EPDM rubber has high wind resistance, ranging from 1 to 60, 1 to 90, and 1 to 120. This is great for commercial roofs where it matters.


EPDM has good resistance to impact damage, especially when reinforced like the fleece backing system. However, as EPDM rubber nears the end of its useful life, it becomes more fragile and more prone to impact damage.

Cons of Rubber Roofing (EPDM)

Cons of Rubber Roofing (EPDM)

Absorbs UV rays

This can be an advantage or disadvantage depending on the type of EPDM material used. The material is also 100% recyclable and eco-friendly, which is great for companies trying to go green. Most EPDM rubbers are black, which means that it absorbs UV rays and heats the roof. They produce white EPDM rubber that reflects UV rays and reduces energy costs. However, the most commonly used EPDM rubber is the common black color.


From what I’ve seen, EPDM seams aren’t as durable as TPO or PVC seams. The adhesive between the seams can tear if the EPDM rubber expands and contracts with temperature changes.


EPDM rubber is by no means a “feast for the eyes.” It’s black and looks like a hose that doesn’t look as good as TPO or PVC, which looks clean and elegant in white. There is an added benefit of TPO that it is 100% fully recyclable! 

Must be installed correctly

If the EPDM rubber roof is not installed correctly, it will leak from day one. It’s important to have a roofing contractor that knows what it’s doing. The National Roofing Contractors Association (NRCA) defines a low-slope roof to have no greater a slope than 25 percent, or 3 inches of vertical rise for every 12 inches horizontal.

Corrosion from petroleum products

EPDM rubber degrades when exposed to petroleum products.

Learn More: Roof Framing Plans

Commercial Metal Retrofit Roofing: Pros & Cons

Commercial Metal Retrofit Roofing

Pros: Metal Retrofit Roofing

Refurbishing a metal roof is an easy and inexpensive way to cover an old unused metal roof with a durable membrane.

The main advantage is the cost of modernizing the metal roof. Not only does this material significantly extend the life of the roof, but it is also not as expensive as a traditional metal roof replacement. While having a metal retrofit roof installed over your existing metal roof can extend the life of your roof by up to 20 years, a complete metal roof installation is generally estimated to last between 30 – 60 years.

During installation, the original metal cover protects the interior of the building so that you can continue with your daily work after work is finished. This protects your employees, your stock and does not stop production.

Customization is also environmentally friendly. Without removing the cover or damaging/dismantling the materials reduces landfill waste and makes the cover an attractive choice for those who respect the environment.

When renovating a metal roof, you can benefit from the reuse of existing roof insulation and additional membrane insulation. This saves energy and ensures a constant building temperature.

Cons of a Retrofit metal roof

While installing a retrofit metal roof over an existing metal roof can extend the roof’s life up to 20 years, an all-metal installation typically takes 30 to 60 years.

Keep in mind that this significantly increases costs and can be more affordable with a simple upgrade.

Types of Flat Roofs: FAQs

Which roof is best for a flat roof?

For many projects, we prefer PVC roofs as the best flat roofing material on the market. PVC roofs are slightly more expensive than other commercially available single-ply materials but offer various cost advantages.

What is the longest flat roof?

The most popular flat roofing material is PVC membrane. It has an estimated lifespan of 15 to 30 years, making it the hardest flat roof material you will find. You can get a fairly good idea of the estimated cost to cover a flat roof based on the national average: It is not surprising that many roof manufacturers only install flat roofs if they are made of PVC. Estimated costs are $7.50 to $12.50 per square foot installed, depending on the project and location.

How frequently should a level rooftop be supplanted? 

By and large, a decent quality level rooftop will last around 10 years, yet with sufficient inclusion, it can last any longer. Fixing is an incredible method to broaden the existence of your level rooftop and diminish the number of fixes you may require.

Why are flat roofs so expensive?

In terms of cost, flat roofs tend to be more expensive than sloped roofs. Flat roofs consist of several levels and usually require the installation of thermal insulation.

Do flat roofs cause problems?

Level rooftops prompt harm. However, in my own experience, problems with flat roof leaks often arise from insufficient roof cladding, poor maintenance by the builder, or age.

Are flat roofs leaking anymore?

The main reason flat roofs are likely to leak is because they have less water to leak out. That is, they prevent elements like water from sliding off them as easily as steep roofs. That is why they are also known as low roofs.

Is It Bad To Buy a Flat Roof House?

There’s no reason not to, but they don’t always have a good reputation and can cause insurance problems. This can create problems finding a mortgage lender willing to offer you an extended flat roof mortgage.

Will a flat roof put a strain on me?

The base prerequisite for level rooftops is to help a concentrated load of 100 pounds for every square foot in many areas.

Why do houses have flat roofs?

It rains or snows in any weather. There is no snow and very little rain in some places, so flat roofs have less debt and almost always cost less than a normal corner roof.

What are flat roofs used for?

Flat roofs are an old form mainly used in arid climates and allow the roof surface to be used as living space or a residential roof. Whether you have a commercial or residential building, some type of roof covering is 100% mandatory. Flat or low roofs are also common in commercial buildings around the world.


Flat roofs may not be the most attractive option for homes and buildings, but they have their advantages. Keep these and consider them when deciding how to get the best roof for your building.

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