The Biggest Advantage and Disadvantage of Flat Roofing

When driving by the local superstore, or some residential housing, you may notice some buildings don’t have the archetypical triangle protecting them from water accumulation. Somehow, flat roofs exist without causing any significant problems. 

The question remains, why do some residents still prefer flat roofs? Won’t water from rain and snow pool up in the roof’s center and cause massive amounts of damage to the structure? What about other debris that lands on it? 

Despite its unpopular appearance, there is a functional reason for the existence of flat roofing. There are also some creative advantages that flat roofs have over standard roofing.

The Biggest Advantage

When considering a building project, sometimes the most important factors that go into the materials and design can be summarized in one word: Cost-efficiency. 

Some homeowners and commercial enterprises want their roofs to be as affordable as possible. On the other hand, they want the top to be reliable long enough not to be an immediate problem.

Flat roofs are by far the cheapest and fastest design to build. This is because flat roofs lack the intricate support structures of a regular roof. Therefore, they don’t require as much material and expertise to make. Visit our website for more information on economical roofing solutions.

Cost-Effective Materials

Inexpensive “tile” options contribute to the cost-effectiveness of flat roofing. They are limited to a few specific types, which fall under the “rolled roofing” category. Flat roofs use sheets of either rubber, Bitumen, EPDM rubber, or TPO (thermoplastic olefin). PVC (polyvinyl chloride) is another popular option. 

Each of these types have different properties. However, the advantages and disadvantages are fairly similar. Rubber, TPO, PVC and Bitumen are good insulators of heat and weather-resistant for at least ten years. 

While the materials are affordable in comparison to pitched roofs, flat roofing can become expensive if you’re dealing with large surface areas. Also, materials like TPO and PVC require special expert installation and equipment.

The Biggest Disadvantage

The main disadvantage of flat roofing is the water build-up from a lack of filtration. Puddles tend to form and remain on sections of the roof, especially in areas where tiles are slightly uneven.

Many flat roofs contain internal drainage systems to counter this disadvantage. The drains are set near the middle/ side areas to prevent what is called “ponding.” Other troughs (or  scuppers) can be added to the edge, though ponding is still most likely to occur in the center, destroying the material and causing leaks over time if not treated. Water should not accumulate on a roof longer than 72 hours.

Creative Ideas for Flat Roofing

Just for fun, we’ve decided to include a few ideas for how you can use a flat roof creatively. These might impact your roofing decision.

An exciting solution to ponding (the flat roof’s most significant disadvantage) is to go the environmental route with a sod top. Sod roofs, or “green roofs,” are widespread for flat-roofed buildings and involve growing a patch of grass in place of traditional roofing materials. 

These living roofs come in 3 types depending upon the medium grown. Typically various sedums are grown & installed in modular trays that are connected. They’re able to withstand harsh conditions and minimize water loss.

In other words, it is possible to convert a bland, flat roof into a garden. Even without a garden, green roofs provide an exciting and efficient material.


Flat roofs also have an extra key feature- that being space. Most sloped roofs require special fastenings and creative solutions to install certain features like air conditioners. They are also very dangerous to walk on. Flat roofs are safe because they are flat, making it possible to climb/ store external items on top of it with little worry. 

Rooftop Patio

Another innovative feature of a flat roof is its possible use as a patio or porch. Most sloped roofs require extra modifications to build an elevated outdoor section, whereas flat roofs are pleasing just as is.


To conclude, flat roofs are not a malfunction of poor or cheap planning. These roofs do have certain practicality to them. It is still essential to understand these systems’ unique physiology and applications, as they are very different from their pointy cousins. 

Request A Free Roofing Quote

Simply call our office or fill out this form to request a free on-site visit from one of our professional consultants.

Mon - Fri: 9:00 AM to 5:00 PM

Sat: By appointment only

Sun: Closed

Request A Free Estimate

    Do you own the building at this address?

    What is this quote for?

    When do you need your roof?