Waterproof for Flat roof: all you need to know

The roof of a home is often forgotten, perhaps because it is out of sight. Nonetheless, this relevant part of your building faces continued exposure to moisture and other harsh elements. This causes weakening and fast deterioration of your roof if regular maintenance checks aren’t in place. To ensure you get the most out of your beam and block flat roof, hence the need for waterproof.

When it comes to flat roofs, the proposes of ensuring your roof longevity, there are various aspects of the process you need to take into consideration. Unlike sloped roofs that drains the water, flat roofs have a very shallow slope of approximately ¼ of an inch, which affects their draining capacity. They also tend to collect debris such as leaves and branches, which further affects the draining capacity. To ensure you get the most out of your flat roof, you need to know more about waterproofing and an effective waterproofing system in that case.

What is waterproofing?

Waterproofing is a procedure that helps to prevent rainwater or any liquid from penetrating the beam and block the flat roof slab and damage your structureThe technique is widely used in flat roofs to help control the effect of any kind of liquid from penetrating the system. The process guarantees impervious barrier established using:

  • Durable and elastic liquid waterproofing membrane
  • Polyurethane liquid membrane
  • Cementitious materials
  • APP membrane from bituminous.  

Importance of waterproofing

Waterproofing is paramount as it helps reduce humidity on the flat roof slab and protects it from damage caused due to water exposure. It is also essential for the credibility of the building as it helps maintain the strength and durability of the concrete surfaces. Other benefits of waterproofing your rooftop slab include:

  • Reduce the Risk of Water Damage to your flat roof slab
  • Extends the shelve life of your flat roof slab
  • Improve Overall Performance
  • Prevent cold-related health issues
  • Reduce the Risk of Leakages
  • Increase the Property’s Value
  • More Energy Efficient
  • Reduce Repairs, Maintenance, & Replacements needed on the roof

How to WATERPROOF your flat roof slab

The approach you use to waterproof your roof depends on various factors, including your location, the weather, type of structure, size, and your budget. These are just some of the determining factors. However, the method you use should stop water leakages from your flat roof structure instantly. Three main flat roof waterproofing methods for flat roof include:

  • Liquid waterproofing
  • APP bitumen membranes
  • single-ply membranes
APP bitumen membranes

If you are looking for the best waterproofing method for your flat roof, you can this method because it is normally recommended for low-sloped roofs because of its proven performance.  The APP membrane (Atactic Polypropylene Membrane) is a waterproofing material that comes in rolls. Each roll is 10 meters long by one metre wide, which covers approximately an 8.7 m² area. With proper installation, this waterproofing material is durable and very efficient when used on a flat roof.

Liquid waterproofing 

Liquid waterproofing is the use of a particular type of coating to weatherproof your flat roof. Some Liquid waterproof products, such as the Liquid Styrene-butadiene copolymer latex, are “designed to use with cement compositions”, according to Kenbro. Depending on the quality, Liquid waterproofing can last anywhere between 20 to 40 years after application. Another common liquid waterproofing material for the flat roof is the fleece liquid membrane

Cementitious Waterproofing

Cementitious waterproofing USE materials are easily available in the market. This method is used in wet areas like toilets and bathrooms. but some people might decide to use it for a flat roof. However, the expansion and contraction take place in cementitious waterproofing when exposed to sunlight.


Flat roofs are becoming more and more desirable as they can typically be used in most housing projects, including commercial and residential buildings. While waterproofing protection might seem like a relatively minor component of your overall flat roof slab construction costs, it is a vital component that determines your flat roof longevity and overall structural integrity. It also maximizes the benefit you get from your beam and block flat roof slab.

At EcoConcrete, we understand the challenges of protecting your roof slabs from the damaging effects of water. We also understand how important your property is. Waterproofing will enhance the roof performance us it protect your roof against leaks and other hazards. 

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