An Overview of Waterproofing Membranes Types


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Your roof, floor, and walls need to be waterproofed to protect your property from rain and excess water. A waterproofing membrane is a protective layer that prevents water from leaking or damaging a surface. Several types of membranes can be differentiated by application and materials. In this article, you'll learn about the various types and benefits when choosing a waterproofing membrane.


Waterproofing membrane types

In general, waterproofing membranes are either sheet-based or liquid-applied. Although neither option is inherently better than the other, it all boils down to the building development requirements, time allowance, budget and environmental conditions. A professional waterproofing contractor should be able to recommend the ideal membrane,, depending on your requirements. Waterproofing membranes can be applied on various structures and surfaces for waterproofing,, such as:

  • Toilets & Bathrooms

  • Roofs & Balconies

  • Decks

  • Basements

  • Swimming Pools

  • Large Commercial & Industrial roofs

Sheet-based Membrane

Usually, sheet-based membranes come in rolls. A flat surface is prepared by unrolling and laying them on it. There are various types of sheet-based waterproofing membranes chosen based on how they adhere to the surfaces being applied. Application methods for membranes include torch-on applied membranes, self-adhesive membranes and liquid-adhesive membranes. Torch-on membranes are the most common application method in Singapore. The bituminous waterproofing membrane is one of the most popular sheet-based membranes.

Torch-on Membrane Waterproofing Singapore
Hydro-seal Engineering Technicians Performing Torch-on Membrane Works

Bituminous Coating Membrane

Also known as asphalt, it is one of the best waterproofing materials that can be used to insulate surfaces against water and moisture content. It can withstand building movements and UV rays.


The benefits of bituminous waterproofing

  • The application process is simple and flexible

  • There is no odour

  • The material is fit for larger application areas

  • Easy to maintain

  • Long-lasting

  • Uniform thickness of membranes

Modified bitumen membranes contain asphalt, polymers, tackifiers, and materials to stabilize the membrane. Fibreglass, polyester, or a combination of these may be used to increase strength and durability. When exposed to the weather, bitumen membranes typically have surface coverings such as mineral granules, coatings, films, or other opaque materials.


Torch-on Membrane

Torch-on membranes are great solutions when it comes to protecting exterior areas. This waterproofing membrane consists of polymers and bitumen that provide resistance to moisture. This method can also be used to prevent water from building up on flat surfaces.


A heated torch is used to apply roof membrane layers by melting them onto the surface. A wide variety of waterproofing jobs can be accomplished with this method, which is both environmentally friendly and reliable. A polypropylene-based asphalt known as Atactic Polypropylene Plastic (APP) and Styrene Butadiene Styrene (SBS) are popular types.


The benefits of torch-on membrane waterproofing

Suitable for areas that are fully exposed to water

Ensures environmental sustainability

Durable and long-lasting

The installation process makes less noise compared to other methods

Protection from strong solar radiation


Disadvantages of sheet-based membranes

The disadvantages of sheet-based membranes are minimal. They include:

  • Having the required size be cut to fit the area exactly

  • Requires special attention to seams, changes in plane or penetrations

  • Labour intensive application process

Liquid Applied Membrane

In contrast to sheet-based products, a liquid applied membrane can be sprayed, rolled or brushed onto the surface. The liquid cures to form a solid membrane either through evaporation of solvent or water, reaction with moisture from the air or in the case of a 2-component product,, the reaction between both components when mixed. The result is a monolithic, seamless, joint-free membrane formed without overlapping, welding, or seams. Some types of liquid waterproofing membranes include water-based, solvent-based, or cementitious-based.



Liquid-applied Membrane Waterproofing Singapore
Hydro-seal Engineering Technician Applying Liquid-applied Membrane

The benefits of a liquid-applied membrane

Membranes made of liquid applied polymer gel are waterproof and durable, further strengthened by adding glass fibres. As it offers a visually more impressive look than other waterproofing methods, liquid applied membranes are commonly used on older roofs. Other benefits include:

  • Material composed of a single component

  • Extremely easy to apply

  • Ensures full coverage of surface including corners

  • It fits both horizontal and vertical surfaces

  • This material can handle soil conditions as well as contaminated groundwater.

  • A cold application method and brush installation are both possible

The disadvantages of a liquid-applied membrane


Simiar to sheet-based membranes, liquid-applied membranes do come with a set of disadvantages. However, modern waterproofing technology is fairly advanced hence the downsides are limited. The disadvantages of liquid-applied membrane method are:

  • The possibility of air bubbles due to incorrect substrate preparation.

  • Inconsistent membrane coverage of surfaces, especially uneven surfaces

  • Longer completion time due to the drying process

These disadvantages can be mitigated if a professional waterproofing contractor performs the necessary preparation and executes the application well.


Contact Hydro-seal Engineering

Hydro-seal Engineering has assisted residential, commercial and industrial clients with membrane application since 1995. Whether it is sheet or liquid-applied membrane, Hydro-seal Engineering has years of expertise to assist you with your project.


Contact us at 6289 6811 for a free inspection and diagnosis of your property.