A Complete Guide on Waterproofing

Waterproofing is integral to maintaining the integrity of a building structure. A comprehensive waterproofing system minimizes post-completion problems and reduces water damage from mould growth and rusting. A successful waterproofing foundation is based on drainage design, product selection, substrate preparation, membrane detail, inspection, and testing, and quality assurance. Waterproofing systems are designed to work under different environmental conditions and applications. 

Membrane Systems

The membrane type and primer determine how well a membrane system can bond with the substrate.  Waterproofing membrane systems are designed to prevent water seepage into the protected building components. There are two types of membrane systems, including

  • Hydrophilic systems consist of particles that crystallize upon coming into contact with water, thus preventing water ingress. 
  • Hydrophobic membrane systems block pores in the concrete to prevent water ingress.

Importance of Waterproofing

Waterproofing errors can cause all sorts of problems for construction companies, property managers, and developers. Waterproofing comes at a trivial cost as far as the whole construction work is concerned, but rectification and remediation expenses can prove costly from damage brought about by water leakage. The resulting damage from waterproofing mistakes accounts for 80% of construction defects.

Primary forms of waterproofing defects are roofing failures and internal water damage. The alarming rise in the number of building defects is caused by waterproofing failure. Rising dampness and water-logging are primarily responsible for waterproofing leakage.

Experienced waterproofing contractors know how different types of leaks are caused. They are trained in handling every source of leaks and applying waterproofing membranes to external and internal wet areas. 

Types of Waterproofing Membranes

Polyurethane Waterproofing Membranes

Polyurethane membranes can be applied on different substrates, such as concrete, rooftops, and cement sheeting. Since polyurethane is highly flexible, it is an attractive choice for properties with a lot of movement.

Polyurethane membranes are durable waterproofing solutions and can be either sprayed with a spray machine or rolled traditionally. The membrane may require a coating in some environments to protect against UV rays.

Rising Damp Waterproofing

​​​Rising damp problems are common in most old buildings that were built without waterproof courses. It is caused by the flow of moisture from the ground up through the wall capillaries.

A damp-proof course is built to prevent moisture from rising by capillary action or rising damp. 

Acrylic Waterproofing Membranes

Acrylic membrane systems are primarily used in internal wet areas and are highly durable. They are available in three forms, including solid bead, polymer and emulsion. Acrylic is a preferred waterproofing application in toilets, swimming pools, terrace, water tanks, sunken portions and asbestos roofs.

It binds two different types of materials, including new and old concrete, wood and concrete and metal and concrete, and used in patch repair of concrete. 

Torch-on Waterproofing Membranes

Torch applied membrane is a type of waterproofing used in retaining and binder applications. The most common failure is the overlapping of edges. The heavy-duty form of waterproofing enables heavy traffic.   

PVC waterproofing

One of the most preferred waterproofing options, PVC waterproofing is highly durable waterproofing options in Australia that require no maintenance or replacement. Since it has high-temperature tolerance, it is an excellent choice in such locations where temperatures soar up, rooftop soiling and contamination. It is highly resistant to impact.

Sheet Waterproofing Membranes

Their simple peel-and-stick application makes them ideal for use in industrial plants, shopping centre rooftops. Their application requires no heat and fumes and thus considered an environmentally friendly waterproofing solution without any volatile organic compounds.

Bentonite Waterproofing Membranes

A unique combination of sodium bentonite and a thick geo-membrane liner makes bentonite waterproofing membrane a preferred choice in building resurfacing projects. Easy to apply, a reactive bentonite compound is used to seal small punctures. Bentonite forms a continuous membrane upon contact with water. When pressure is applied, it forms a dense seal.

The selection of a proper waterproofing membrane system requires due consideration of the location. The membrane and primer type are key determinants in determining the adhesion capacity to the substrate. 

Locations

Internal wet areas, including bathrooms, require intense rectification and defect works due to constant wear and tear from exposure to water. The most common waterproofing membrane systems for internal wet areas include acrylic or polyurethane. 

However, attention must be paid to the compatibility between the adhesives and membrane. Another factor that requires due consideration is timing. Tiling must be done within 24 hours of membrane curing in some membrane systems for adhesion.

External wet areas, including balconies, require waterproofing since they are high-risk areas. Since they are an integral part of the building, the right drainage solution and membrane detail are required to avoid water leaks. Drainage outlets are carefully planned during building resurfacing to provide a good waterproofing system. 

Roof plant rooms are watertight to prevent water leakage. An external roof plant room requires an ultraviolet resistant membrane, which is durable and resistant to slip and abrasion.

The best waterproofing system is installed perfectly to drain away water and avoid waterproofing failures, such as mould growth, membrane bubbling, ponding of water and wet walls.

There is a high risk of water penetration if a waterproof failure occurs, and there are conditions like rising damp. Ponding of water risks causing waterproof failure and water penetration.

Careful consideration and proper waterproofing membrane application techniques involve 

  • Surface preparation with concrete
  • Caulking
  • Membrane installation and protection

Hardening concrete requires different surface preparation techniques to ensure proper adhesion of the membrane to the substrate. Waterproofing to concrete, which is 28 days old, must be avoided. The reason is that high moisture content of concrete might cause blistering or bubbling of the membrane.

Concrete older than 28 days old is apt for waterproof membrane installation. Appropriate waterproofing products act as a barrier to moisture and prevent the substrate from failing. 

The Waterproofing Experts Are Here

An experienced waterproofer reviews the type of surface preparation to prevent waterproofing mistakes that could result in mould growth. Waterproofing is a specialized process that requires a licence from the Queensland Building & Construction Commission. OPAT prides itself on being a leading waterproofing contractor in Queensland.

 Our experts keep up to date waterproofing technological innovations to ensure a quality outcome whether it is a new construction, rectification, or building resurfacing project.

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