Waterproofing in a Nutshell | Do You Need to Waterproof?

Besides fire, one of the worst things that can happen to your building is water penetration caused by lack of waterproofing. It has resulted in many buildings losing structural integrity and even collapsing.

When building your home, nobody needs to convince you to get a roof (which is made using waterproof material); but what about waterproofing solid concrete structures such as bathroom floors, balconies, concrete gutters, retaining walls, and basements? Not many people understand what concrete waterproofing is or why it is important.

Diverse opinions abound on what should be done on concrete surfaces such as the aforementioned. Some opine that it is better to set aside a budget for paint instead of specific waterproofing materials. This reasoning, however, only works for short term gains and fails to take into account that any water that will find its way into your house through either the foundation (ground water) or the concrete gutters (roof water), will land directly into your walls thereby damaging the same expensive paint and in some cases leaving you with a weak foundation.

What is Waterproofing?

Waterproofing is a protective measure that sees the application of a layer of an impermeable material to halt water from penetrating a structure or an object. The process guarantees that a smooth system is established through the application of durable and elastic membranes. The technique is widely used in the construction industry to control the effect of environment liquid penetration into the system. It helps maintain the strength and durability of concrete surfaces.

Types of Waterproofing materials

There are various sophisticated waterproofing systems available worldwide. The type of waterproofing product to purchase is mainly dependent on the area you need to waterproof. We come across waterproofing failures arising from poor workmanship, wrong product used on the wrong surface and failure to follow the manufacturer’s specifications.

Waterproofing membranes are the most common waterproofing systems used in Kenya.

Liquid Waterproofing Membranes

This method involves applying a thin coating mostly consisting of a primer coat and two other coats of the liquid waterproofing solutions using either a roller, brush or by spray. Its durability is usually determined by the polymer the manufacturer used to make the liquid waterproofing membrane. This type of membrane is mostly recommended for internal use such as bathrooms that will not be exposed to the harsh UV Rays.

Bituminous Waterproofing Membrane

Due to its performance, bituminous waterproofing membrane method is usually used when waterproofing low-sloped roofs, concrete gutters, basements and retaining walls. The most commonly used bituminous membrane in Kenya is the APP membrane. APP stands for Atactic Polypropylene. APP waterproofing membrane on the other hand, is bituminous which makes it stronger and with better climatic changes impact resistance. The application method is through a heated blow-torch making the surface bonding stronger and consistent.

Where is Waterproofing Used?

Waterproofing is required in several locations in a building.


Waterproofing is vital as this is the area with direct contact with the earth surface. Basements are prone to water seepage from the surrounding into the building structure.

Bathroom, kitchen, and toilet

Water is continuously used in these places, thus proving to be a critical location for seepage.


Water from the rain and utility works makes it necessary for the area to be waterproofed.

Swimming Pool

This area is always filled with water, thus presenting the highest chances of leakage.


The area is open for any form of seepage thus the need for it being waterproofed.

Why is Waterproofing Important?

  • It helps save money in the long-run.
  • It prevents damage to the structure.
  • It prolongs the life of the structure.
  • It is easy to install at the initial construction stage
  • It helps protect the interiors

What to Consider when Waterproofing

When it comes to waterproofing, one has to consider several things. For example, one has to decide on the membrane to use. Every membrane has features that make them unique from the other.

For instance, when using the reinforced bituminous membrane, one should consider the heavy lifting and heating equipment that is required. Finally, the condition of the area to be waterproofed should be taken into account as the surface should be prepared accordingly to receive the membrane.

Would you like to know more about Waterproofing concrete structures and flat roofs? We conduct a FREE program ‘’Roofing 1on1’’ at our REXE Showroom on Menelik Court, off Menelik Road and we would love if you could pay us a visit. Feel free to Get in Touch with us for more information on our Roofing materials and products which include supply and installation of APP Waterproofing membrane, Roofing Shingles and Stone Coated Roofing Tiles among other Roofing Boards and accessories


  • Urban moran

    July 18, 2020 at 5:01 am

    Great education for any prospective person that intends to engage in a construction project.


    • REXE Roofing Products

      August 4, 2020 at 5:20 am

      Thank you very much for the feedback.
      Looking forward to adding great value to all the projects we undertake.


  • Jedida Kinyanjui

    July 22, 2020 at 10:16 pm

    I’d like to know more about waterproofing on flat roof on block buildings, what time do you open?


    • REXE Roofing Products

      August 3, 2020 at 2:07 pm

      Hi Jedida,

      We are open from 8:00am to 5:00pm on weekdays and from 8:00am to 1:00pm on weekends. You can check our contact details


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