What is a Waterproofing Contractor?

A Waterproofing Contractor is a licensed professional who installs membrane systems to protect wet areas such as bathrooms, balconies, and rooftops from water ingress. Their work is essential for preventing long-term structural damage and must meet strict compliance standards under the National Construction Code.

What does a Waterproofing Contractor do?

Your Waterproofing Contractor will complete works according to your agreed scope of works.


Typically, a Waterproofing Contractor will:

  • Inspect substrate conditions and confirm readiness for membrane application
  • Apply liquid or sheet waterproofing membranes to bathrooms, laundries, balconies, and external wet zones
  • Create water stops, upturns, and control joints in accordance with Australian Standards (AS 3740 or AS 4654.2)
  • Allow drying or curing time before tiling or further finishes
  • Issue a waterproofing certificate required for your private certifier or builder


Waterproofing usually occurs after wall sheeting and screeding, but before tiling.

Barry's Toolbox

You only get one shot at waterproofing — and defects can take months to appear. Always confirm your tiler and waterproofing contractor are aligned on timing and floor heights.

What Makes a Good Waterproofing Contractor?

Look for contractors who:

  • Are licensed and insured for internal and external waterproofing
  • Work strictly to the relevant Australian Standards
  • Use high-quality membranes suited to your application (e.g. under-tile, exposed, UV-rated)
  • Provide photographic records and a waterproofing certificate
  • Coordinate well with your tiler, plumber, and builder

Before You Begin: What You’ll Need Ready

To get quotes from Waterproofing Contractors, you’ll need:

  • Detailed plans showing all wet areas and balcony locations
  • Confirmation of substrate type (e.g. concrete, compressed sheet, screed)
  • Any floor heating or slope requirements already completed
  • A clear construction program to confirm install dates

Average Timeframe

For this task, Pros typically provide quotes within 7-10 business days.

When Can I Expect Quotes?

Timeframes often vary based on demand and the type of Pro you're engaging (e.g. a plumber). If additional communication or clarification is needed is needed, the quoting process may take longer.

 

Don't be alarmed if you don't receive quotes or communication from any Build Buddy Pros straight away. Some work is more complex and the Pro may need time to comprehend your documents or scope of work. Depending on the job, there may even be some work required by the Pro before they are able to quote (e.g. a site visit might be required).

 

If the average timeframe indicated here has passed, and you have not received any messages or quotes, please feel free to contact the Build Buddy Expert Guidance and Support team for an update on quoting for this task.

Frequently Asked Questions

  • Do I need waterproofing in laundries?

    Yes — in most states, laundry floors must be waterproofed or water-resistant. It’s typically included in the scope by default.

  • What’s the curing time after waterproofing?

    Usually 24 to 48 hours, depending on the product. Tiling should only begin once the membrane is fully cured to avoid failure.

  • Does waterproofing come before or after screeding?

    Internal areas often need waterproofing both below and above the screed — your contractor will advise the right approach for your site.

How to Complete this Task?

STEP 1

Review and Adjust the Scope of Works

Timeframes may vary based on demand and the type of Pro you're engaging (e.g., a plumber). If additional communication or clarification is needed, the quoting process may take longer.

STEP 2

Confirm Required Documents Are Uploaded

Check that the following required document(s) are uploaded for this task. These are essential to proceed:

STEP 3

Update the Quality Assurance Checklist

Go to the Quality Assurance tab in this task and review the checklist. Edit any details to suit your project requirements. Being clear and upfront helps set expectations with the Pro. Updating the checklist before requesting quotes ensures everyone is aligned.

STEP 4

Request Quotes

Click the orange ‘Request Quotes’ button to start the quoting process.

STEP 5

Review the Quotes

Once you receive quotes:

  • Review each one carefully, including the payment schedule and any special terms
  • Download attached quote documents for detailed review
  • Check each Pro’s profile and read past client reviews

STEP 6

Communicate with the Pro

If needed, message or call the Pro to clarify details or negotiate terms.

STEP 7

Accept a Quote

Choose the quote that best suits your needs. Once you accept a quote, any other pending quotes will be automatically declined. An agreement will automatically be generated.

STEP 8

Complete the Tasks In Your App

New tasks will appear to guide you through this job — follow each step carefully. Make sure to use the Quality Assurance Checklist, and refer to your contract and final Scope of Works whenever needed.

NEED HELP?

Reach Out to Your Build Buddy Pro

If you have any questions or need a hand, your Build Buddy Pro is your best first contact. They’re a licensed expert in their field and can understand the ins and outs of your project. You can message them via the platform, or you can call them directly.


If you have already contacted your Build Buddy Pro and still need further assistance, the Build Buddy Expert Guidance and Support team are here to help. They will be able to guide you on your next steps or help you find answers to any questions you may have.