Waterproofing Systems We Specialise in

The waterproofing systems that Revo-seal installs for clients are able to withstand the effects of Singapore’s tropical climate of high humidity and heavy rainfall, two factors that demand the latest waterproofing technology and techniques to protect a building against the elements.

Often, waterproofing is confused with damp-proofing. The former is a system that prevents water seepage into buildings; the latter, a method of resisting water vapour.

Internal, external, and blindside waterproofing

Depending on the type of building and its water resistance requirements, a waterproofing membrane may be located internally (negative), externally (positive) or in places that are inaccessible under normal circumstances (blindside).

Internal waterproofing

The key advantage of interior waterproofing is that it’s accessible for future updates or repairs. However, it doesn’t stop water from getting into wall and floor substrates.

The most frequently-used applications in internal waterproofing are cementitious coatings and epoxy injection.

External waterproofing

An external waterproofing system protects a structure from the effects of the weather, and can be applied to the areas of a building that are above ground (above grade), the portion of a building that’s below ground level (below grade), or at ground level (at grade).

A drawback with exterior waterproofing is that it’s unreachable after construction without the time-consuming and costly process of digging out soil all around the building.

Blindside waterproofing

Blindside waterproofing is a complex procedure, entailing application on top of a soil-retention system, before masonry or concrete foundation walls have been poured.

Sometimes, though, it’s the only solution, when for example, neighbouring structures or property lines restrict access and excavation.

Types of waterproofing membranes

To fulfil its primary function of resisting the hydrostatic pressure caused by a build-up of water, a waterproof membrane needs be flexible, robust, and elastic. With these properties, it can then cover crevices and cracks while coping with movement in the building (buildings shift all the time but usually these movements are imperceptible).

Waterproofing membranes comprise thin layers of water-resistant material that cure to form a seamless barrier against water intrusion. Typically, this membrane is sited between the substrate of a wall or floor and the finished surface. For example, in a shower stall, the membrane would be between the plasterboard and the finish tiles.

The 2 types of waterproofing methods commonly used in Singapore are:

1. Sheet-based
2. Liquid-applied

Sheet-based waterproofing membranes

Sheet-based membranes, often utilising the viscous properties of bitumen, are rolled out onto a firm surface. The material is fixed to the substrate with a hot tar-based adhesive, using blowtorches.

Roofing felt is one example of a sheet-based waterproofing membrane. Other sheet-based applications include PVC and composite materials.

Liquid-applied waterproofing membranes

Liquid-applied materials are sprayed or brushed onto surfaces, the liquid curing to create a seamless membrane.

This method of waterproofing has the advantage that it doesn’t entail joints, like sheet-based systems. However, if a membrane created by liquid application is too thin, it can break down or tear.

Common waterproofing materials used by our clients

Revo-seal will take these factors into consideration when recommending the waterproofing system to apply on your premises:

• Where the site is located.
• Design and location of the amenities situated on the site.
• Type of surface the waterproofing material is to be applied on.
• Gradient of the surface.
• Whether the surface is stable or there’re frequent shakes.
• Amount of foot or vehicular traffic on the site.
• Frequency and amount of water ponding.
• Exposure of the waterproofing membrane to the sun’s ultraviolet (UV) rays, chemicals, and heat.
• Resistance to the roots of plants (if the site is a green roof or has planter boxes).
• Conventional local practice.
• Durability of the waterproofing membrane.
• Total cost of the installation of the waterproofing membrane.

Waterproofing systems can be categorised into:

1. Preformed membranes. These systems may be bituminous (such as asphalt and bitumen) or non-bituminous (e.g. bentonite clays and polyvinyl chloride (PVC)).
2. Liquid applied membranes. Such systems may also be sub-categorised into bituminous and non-bituminous. Examples of non-bituminous membranes are acrylic, polyurethane (PU), and cementitious.
3. Integral systems. They consist of crystalline waterproofing, chemical admixture, and waterproofing screed.

There’re many different materials available designed to prevent water incursion in residential, commercial, and industrial premises, and we’ll know which ones are best for your particular building.

Let’s take a brief look at the ones we implement for our clients.

Acrylic

Acrylic waterproofing materials, which are applied as liquid, are highly elastic and very durable. They’re often used in roof and balcony waterproofing.

Bitumen

Bituminous waterproofing membrane is highly resilient against water penetration, and often used in roof waterproofing. It can be applied as liquid or in sheeting form.

Cementitious

Cement-based waterproofing materials are comparatively inexpensive and easy to apply. They’re liquid-applied, often in layered coatings.

Epoxy

The epoxy waterproofing system is an efficient, liquid-applied solution for sealing cracks in concrete, and is often used to waterproof car parks.

Polyurethane (PU)

The polyurethane waterproofing material is a crystalline compound that’s applied as a liquid to create an impermeable membrane. It usually lasts longer than bitumen-based materials.

Liquid, sheeting, and injection systems

The varying materials used in waterproofing have their own specific application requirements.

Liquid

Membranes formed from waterproofing materials in liquid state that are trowelled, brushed, mopped, rolled, or sprayed onto a surface. Liquid membranes cannot be removed or relocated.

Sheeting

A sheet or film waterproofing system involves the use of adhesives, mortar, tapes, fasteners, and fire torches. The composition of the resulting membrane may consist of bitumen, bentonite clay, rubber, or reinforced polymers.

Injection

An injection process is used when an existing construction needs waterproofing repairs or improvements. Holes are drilled through walls and floors, though which liquid polyurethane, bentonite clay, or epoxy is then pumped.

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