Some Frequently Asked Questions on Waterproofing

How do I select the best waterproofing method for my project?

There are many different waterproofing systems, and it can be difficult determining what approach is best. Always consult a reputable waterproofing contractor to ensure the right products are used in the right areas.

Can I waterproof my basement from the inside?

Yes. If the basement has rising damp or active leaks it can still repaired it from the interior. No matter what time of year it is, if your basement has suddenly started leaking, it can be waterproofed to protect you, and your family from the effects of water damage.

How long will my waterproofing last?

Most membrane manufacturers warrant their products for 7-10 years. This is not to say your waterproofing will not last longer. If the system is installed correctly waterproofing can last upto 20 years or more. It comes down to the structural integrity, the membranes used and the methods of installation.

Can I repair a crack on my concrete?

Yes you can. There are some specific waterproofing materials that are used for fixing cracks and leakages in concrete.

What causes water leaks in my basement?

There are many different causes, which will include; bad engineering or design, a low landscape, a poor drainage system, shifting of the structure, neighbors yards that are sloping towards your property, a new swimming pool, chemicals breaking down on your concrete walls.

Why are there cracks on my walls?

Cracks are often a result of a settling foundation. They can also be caused by water build up around your foundation which leads to movement of the ground.

Inspect balconies to assess signs of damage or failure such as:

  • Missing or cracked grout.

  • Popped tiles or damaged sand cement bedding.

  • Insufficient drainage.

  • Signs of efflorescence.

  • Damage or cracks in the substrate.

  • Ensure you waterproof the wall

  • Missing or failed waterproof membrane.

  • Excessive movement.

  • Water damage from underneath.

Efflorescence is now considered a building defect! Efflorescence mentioned in the list above refers to salts and minerals that are present in concrete substrates or sand cement beddings. Once wet, the salts and minerals wick up and through grout lines and between tiles giving a white to yellow appearance. The buildup can become quiet severe and begin to engulf whole tiles and cause irreversible damage to floor finishes. Waterproofing on-top of screeds or sand cement beddings can eliminate efflorescence as can admixtures used by tilers in the sand cement mixture.


It is important to waterproof your balcony correctly during the construction stage.

A good contractor will ensure the correct membranes are used and that they are applied to the manufacturers specifications.

It is said that prevention is better than cure. In this case, repairing an already damaged balcony is more expensive than doing it initially.


Click to call for your FREE waterproofing quote

For many real estate developers and homeowners, waterproofing is seen to be a costly undertaking that is unnecessary, but other than fire, the next worst thing that can happen to your home is water damage. We have all seen many houses flooding as a result of heavy downpour.

During construction, wet areas and areas prone to water exposure must be waterproofed to ensure that the living areas remain unaffected by water and kept dry especially during the rainy seasons. It also reduces humidity in the house, which can damage structural materials, furniture, fixings, floor coverings and even affect health.

Your home is probably your most important asset that needs to be protected. A waterproofing contractor will use membranes and other types of coatings and materials to protect the interior and exterior of the house giving structural integrity and will protect the house both inside and out.

Waterproofing starts in the early stages of construction, from the foundations right up to the roof top and landscaping.

Areas that need to be waterproofed:

  • Bathrooms

  • Balconies / Decks

  • Retaining Walls

  • Rooftops

  • Planter Boxes

  • Swimming Pools

  • Terrace or Roofs

There are many benefits to waterproofing your house, which include;

Safety: Waterproofing will keep your family and possessions safe during cold and hot seasons. Water is known to rot timber, cause concrete integrity issues, ruin furniture, floor finishes, fixings and cause different kinds of illnesses if mould is present.

Preservation: Waterproofing will keep your house in good condition for a long period of time, regardless of harsh weather conditions. This will also help keep the value of your home.Waterproofing your house may be expensive, but the benefits far outweigh the cost. The damage that is caused by water will cost tens of thousands of dollars to repair.

Types of waterproofing:

Negative or hydrostatic Pressure Membranes:

These products can be applied to damp surfaces from the inside of structures. They cannot stop active leaks but can stop rising damp and hydrostatic water pressure. They are commonly used in basements from the internal wall to stop water seepage. Common Negative pressure membranes include, Hydrostatic Epoxies, Cementitious membranes & water reactive polyurethanes.

Cementitious Membranes:

This is the easiest waterproofing method used in construction, because the materials used in cementitious waterproofing are easily sourced from suppliers, and are easily mixed and applied.

It is used internally in areas that are normally wet. This is because it is a rigid type of waterproofing that is also semi-flexible.

Liquid Membranes:

A liquid membrane provides a coating which is approximately 1.2mm thick and consists of two top coats and a primer coat that are roller applied. It is more flexible than the cementitious method. The liquid forms a coating which is of rubber-like consistency on the walls & floors that provides an impervious coating. The two main liquid membranes used today are Water Based Acrylic membranes and Solvent Based Polyurethanes.

Bituminous Membranes:

This is a type of waterproofing method that provides a protective waterproofing coating in accordance with the laid out polymerization and formulation grades.

It is also known as asphalt coating and the most common areas of application are below ground and roof tops. It also provides an excellent protection on concrete foundations. This is because it is made from bitumen materials which become fragile and brittle when exposed to sunlight.

Bituminous Sheet Membranes:

This is a method for low-sloped roofs that is very popular because of its proven performance. It is applied as self-adhesive or torched on with a butane torch.

The self-adhesive comprises of polymers, asphalt, and filler. It may also contain some oils and certain resins that improve the adhesion characteristic. It has a low shelf life because the membranes bonding properties reduce with time.

Torch on membranes have covered and exposed types. The exposed membrane contains an aggregate called mineral granular that withstands wear and tear r. The other types of membranes usually requires an extra layer of protective screed to avoid puncture.

TPO or Thermoplastic Polymer Membranes:

This is mainly used on flat areas, such as rooftops as it can withstand extreme exposure to weathering. It can also be used in internal wet areas, balconies and planter boxes. It is very expensive and the costs usually double to triple the price of a liquid membrane system. The system consists of modified polymer sheeting that is heat welded at the seams and has insitu pieces for corners and floor wastes. It requires the most skill of all waterproofing types but is superior in many ways. It is also convenient as it only requires one layer and usually the job can be completed within a day.

Cementitious Plug:

This helps to seal up any large cracks or active water leakages. It hides any untidy marks, and provides an aesthetically appealing coverage. It can be coated over with any negative pressure membrane.

Crack Injection:

This is one of the most superior waterproofing solutions. Crack injection is used for active water leaks, usually below ground and is applied by drilling a port into the joint or crack and using a high pressure pump to inject a water reactive polyurethane. The polyurethane reacts and expands into the joint with contact of water and seals the leak instantly.

Spray Applied Polyurea Membrane:

Spray applied polyurea is one of the newest innovations in waterproofing.It requires little preparation and large areas can be waterproofed in a small amount of time.Spray applied Polyurea is very fast setting, easy to apply and extremely flexible and tough.It consists of a high pressure pump fed from a large drum of solution and is applied via a wand, similar to a pressure washer.


It is important to waterproof your balcony correctly during the construction stage.

As mentioned earlier, there is a common misconception that waterproofing is not very important, but when you think of the possible consequences if your waterproofing was to fail the damages far outweigh the initial cost, prevention is better than cure. A house is constructed to last a lifetime, and your waterproofing is a major contributing factor to it doing so.

The cost of waterproofing is typically 1% of your build cost yet is the most common defect in new buildings. The average house will cost $2500 to waterproof whereas the cost to strip, re-waterproof and refit just a single bathroom can easily reach the $15000 mark.

Protect your valuables,your home and your health by ensuring your waterproofing is carried out by a qualified and experienced waterproofing contractor.