Waterproofing is an important and essential component of a building project. Getting it right the first time is critical as effective waterproofing through the application of membranes keeps your building protected against damage from water and moisture. Failure to do so will lead to expensive ongoing repairs not only to the waterproofing system but also the building.

Incorrectly applied waterproofing is one of the leading defects in the Australian building industry, with inadequate surface preparation, membrane application and curing times some of the primary causes behind most problems. Faulty workmanship can lead to catastrophic outcomes, including the unhealthy growth of mould and mildew, the possible onset of concrete cancer, and water ingress over time, leading to degradation of the building’s structural integrity.

Hiring a Contractor 101

The first step to getting your waterproofing right is to select the right contractor to waterproof your commercial building. Invest sufficient time to create a shortlist of several contractors who may be suitable and fit the basic requirements.

Considerations at this stage would include:


Insist on the best quality waterproofing system for your premises, else you’re exposing yourself to long-term structural problems. Confirm that the selected waterproofing products are appropriate for your building and meet or exceed the requirements of AS 4654.1. Also make sure the membrane is suitable for its intended application, as some membranes have limitations.

Warranty is an important component of a waterproofing product. Most of the time, only the product will be guaranteed and it will normally be for 10 years. On the other hand, if you choose a contractor who is licensed to install Wolfin membrane, you will get a single point warranty on the product as well as the labour.


Any contractor must be fully licensed to do the job and preferably be as experienced as possible. Licensing requirements vary by state and territory, but at a minimum contractors need to successfully have completed Certificate III in Construction Waterproofing (CPC31411/ CPC31408), Waterproofing (General Construction) (BCG31403) or the TAFE equivalent (Course 8126). Always ask to see their licence as it pays to be certain.

It would also help to know if the contractors have completed a similar project to yours in the past and if you can see the results. Do your own research about the contractor online and contact their customers about the quality of their work.


Make sure the contractor you choose is insured so you and your premises are fully covered in the event of any incident. They should have the following types of insurance:

WorkCover: Workers’ compensation that provides wage replacement and medical benefits to the contractor’s employees if they’re injured on the job.

Public Liability Insurance: Protects the contractor from liability if someone sues them for death, injury or damage to property.

Indemnity Insurance: Protects the contractor from liability if they’re found to be at fault for an event due to misjudgement or negligence.

The last two forms of cover simply mean that you’ll have legal recourse available to you if your contractor’s work results in a problem.


Project costing is important; get quotes from at least three contractors and compare what you are getting for your money.

Assess your shortlisted contractors

Now it’s time to look at the attributes of each candidate in your list – the differences at this stage will be more subtle, but can have a major impact on their quality of work.

Key factors to compare at this stage include timeframe, warranty and references.

Timeframe: They may have the right product at the right price, but will they be able to complete the job for you in a realistic timeframe and with the least amount of disruption to your business? Get a completion date in writing.

Warranty: Do they guarantee their products and workmanship? If they don’t, you could be seriously out of pocket if something were to go wrong; so make sure they back their work with a written warranty (at least 10 years) and provide a waterproofing certificate.

References: Every successful business has a track record of satisfied clients and successfully completed projects. These should be displayed prominently on your contractor’s website; alternatively, ask the contractor to provide you with the contact numbers of previous clients.

You’re hired

Finally, having identified the best contractor for the job, the last step in the process is to get everything in writing by setting out the terms and costings for the project in a legally binding contract.

Tick all the boxes

Of course, if you don’t have that sort of time to invest, you could simply contact us at Projex Group about our Wolfin Waterproofing System, which ticks all the boxes mentioned above and comes with a 10-year warranty on both labour and materials. It’s also installed by a licensed applicator, and inspected, certified and warranted by Projex Group.