Flat Roof: Waterproofing Know-Hows

Flat Roof: Waterproofing Know-Hows

Flat roofs are becoming increasingly popular in both residential and commercial buildings due to their aesthetic appeal and cost-effectiveness. However, one major concern with flat roofs is waterproofing.

As the name suggests, flat roofs have a low slope or no slope, making them prone to water accumulation. This can lead to serious damage if not properly waterproofed.

Today, we will discuss everything you need to know about waterproofing your flat roof. From understanding the common causes of leaks to the different types of waterproofing options available, this article will provide you with the knowledge to ensure your flat roof stays leak-free.


Common Causes of Flat Roof Leaks

Before diving into the various waterproofing options, it is important to understand the common causes of flat roof leaks. This will help identify potential problem areas and preventative measures.


1) Poor installation

One of the leading causes of flat roof leaks is poor installation. If the roof is not properly installed, or if shortcuts are taken during the process, it can lead to gaps and weak spots where water can seep through.


2) Lack of maintenance

Flat roofs require regular maintenance to ensure they stay in good condition. Neglecting routine inspections and repairs can lead to small issues turning into larger, costly problems.

It is important to have a professional inspect your flat roof at least twice a year.


3) Ponding water

As mentioned earlier, one of the main concerns with flat roofs is water accumulation. This can happen due to poor drainage or improper installation.

When water sits on the roof for an extended period, it can seep through any small cracks or gaps and cause leaks.


Types of Flat Roof Waterproofing

Luckily, there are several options available for waterproofing your flat roof. Each has its own advantages and disadvantages, so it is important to understand which option would be the best fit for your specific roof.


1) Built-up Roofing (BUR)

Built-up roofing, also known as tar and gravel roofing, is a traditional method of waterproofing flat roofs. It involves alternating layers of bitumen (a petroleum-based material) and strengthening fabrics to create a durable barrier against water.


  • Proven track record
  • Can withstand foot traffic
  • Cost-effective option


  • Heavy and requires additional structural support
  • Time-consuming installation process


2) Modified Bitumen (MB)

Modified bitumen is another popular option for flat roof waterproofing. It is made from asphalt and various modifiers that create a durable, flexible sheet. These sheets are then heat-welded together to form a seamless, waterproof barrier.


  • Resistant to ultraviolet (UV) rays
  • Can withstand extreme temperature changes
  • Easy installation process


  • Prone to punctures and tears during installation
  • Limited lifespan compared to other options


3) EPDM (Ethylene Propylene Diene Monomer)

EPDM is a synthetic rubber material commonly used for flat roofs. It comes in large rolls, which are adhered to or mechanically attached to the roof surface.


  • Durable and long-lasting
  • Resistant to UV rays and harsh weather conditions
  • Easily repaired if damaged


  • Can be expensive compared to other options
  • Requires professional installation for proper adhesion


Additional Tips for Waterproofing Your Flat Roof

Apart from choosing the right waterproofing option, there are a few additional tips that can help keep your flat roof leak-free.

1) Regular maintenance is key

As mentioned earlier, regular inspections and maintenance are crucial in preventing leaks on your flat roof. Have a professional check for any cracks, tears, or gaps that could potentially lead to water seepage.


2) Keep the roof clean

Debris, such as leaves and twigs, can accumulate on your flat roof and clog drainage systems. This can lead to ponding water and potential leaks. Make sure to regularly remove any debris from your roof.


3) Consider adding a protective coating

Applying a protective coating over your waterproofing layer can provide an extra barrier against UV rays, harsh weather, and foot traffic. It also helps extend the lifespan of your waterproofing system.



Properly waterproofing your flat roof is essential to keep it leak-free and in good condition for years to come.

Understanding the common causes of leaks, the different types of waterproofing options available, and implementing preventive measures can save you time, money, and stress in the long run.

Remember to regularly maintain your flat roof and consult a professional for any repairs or concerns. So, next time someone asks you about flat roof waterproofing know-hows, you are well-equipped with all the necessary knowledge.

No Comments

Sorry, the comment form is closed at this time.

Enquire Now
close slider