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How Much Does It Cost to Waterproof a Bathroom?

Last updated: 9th Jun 2019


Bathroom waterproofing services cost around $34.50 per square metre. If you only want a specific area waterproofed, you can expect rates to be as low as $33/m2. However, if your entire bathroom needs waterproofing, you could end up paying about $42.50/m2 to $60/m2 or more for a larger bathroom.

To completely waterproof an average-sized bathroom, expect to pay between $500 and $800 if the work has been carried out by a licensed professional. If waterproofing is a part of a larger renovation project, the cost has probably been already included in the quote and may be lowered.

Where do these prices come from?

All prices stated in this article are based on FY 2016 pricing data compiled by The figures resulted from a comprehensive analysis of quotes submitted by Waterproofing Specialists on the site from July 2015 to July 2016.

When you’re renovating your bathroom, the first elements that come to mind often include bathroom tiling, fittings and fixtures. One of the most important foundations of the bathroom, however, is the waterproofing that lies beneath.

In such a moist environment, waterproofing is absolutely essential in the bathroom to prevent leak-associated issues, including rising damp, peeling paint and plasterboard decay.

Not only will this guide address the waterproofing costs but also the most common questions on the topic, so read on. Let’s start with the basics.

What Is Waterproofing?

Waterproofing is a method of adding a membrane-like layer that lies beneath the tiles and prevents water from penetrating through the wet area walls into the rest of your house. Applied to the surface like paint, waterproofing is a highly flexible, water based, polyurethane substance that creates a protective film when dry.

The waterproofing process usually takes 2 or 3 days and involves 2 coats. The area being waterproofed must be completely cleaned and sealed before waterproofing application. If done professionally, you may expect it to last for 10 to 20+ years.

Image from BA Membranes

Why Is Waterproofing Needed?

Bathroom waterproofing is necessary to prevent a possible damage to your home caused by water leakage.

‘Faulty waterproofing is one of the top three building defects across Australia. It causes the most structural damage to a house alongside termites, and it also causes a lot of stress to homeowners.’

Nathanael Forster, the Australian Master Tilers Association (AMTA)

It will ensure the protection you need and prevent certain problems from happening:

  • water penetrating outside your bathroom and flooding the surrounding areas;
  • damp walls and ceilings at a lower floor due to water leakage in the bathroom above it;
  • dangerous water and electrics mixing because of water leaks;
  • condensation, damp and mould occurrence because water in your bathroom has penetrated the top layer (e.g. wood, plaster, brick or tiles);
  • harmful respiratory problems such as asthma caused by mould and mildew in the air;
  • your bathroom plumbing corrosion;
  • rotting of house beams and other structural timber;
  • increased energy bills during winter because your bathroom external walls haven’t been properly insulated (waterproof boarding is an excellent insulator which keeps the warmth in your home);
  • limited bathroom design options (e.g. you cannot have a modern open plan shower or a wall hung toilet and basin if your bathroom is not properly waterproofed as any other wet room);
  • when you want to sell your house, its value won’t be decreased if it’s waterproofed professionally and according to the legal standards.

Image from Pixabay

By law, waterproofing is an essential and basic requirement of every bathroom. As set out by the Building Code Australia (BCA), the following areas need waterproofing:

  • shower enclosure floors and walls,
  • shower enclosure step and down to the floor,
  • bathroom walls to a height of 1.5m,
  • bathroom floor if on the second floor or higher or made of timber.

Let’s dive a bit deeper into the Australian waterproofing regulations.

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What Is the Australian Standard for Waterproofing?

The Australian standards and minimum requirements for waterproofing a bathroom are regulated by the Building Code of Australia (BCA) and Australian Standards (AS 3740-2010) – Waterproofing of Domestic Wet Areas.

You could check out more detailed Waterproofing Requirements for Wet Areas in the linked information sheet based on a Housing Industry Association (HIA) document, as well as in the following video:

What Needs to Be Waterproofed in a Bathroom?

When it comes to bathroom waterproofing, many people wonder:

‘Do I need to waterproof my bathroom floor? Or just the shower? Must all my bathroom walls be thoroughly waterproofed?’

In short, your bathroom floor, the shower enclosure and the area around your bath and toilet need to be fully waterproofed, unlike the walls and the ceiling.

Bathroom waterproofing must comply with the following basic regulations, which clearly state what exactly needs to be waterproofed in a bathroom:

  • entire bathroom floor must be fully waterproofed if it is on the second or higher floor or if it contains wood or is made of any kind of timber;
  • entire shower floor must be waterproof;
  • bathroom walls are to be waterproof up to 150mm;
  • shower enclosure walls should be waterproofed to 1800mm from finished floor level;
  • the whole area over the hob or step down to the bathroom floor needs to be waterproofed at least up to 100mm.

Do Tilers Do Waterproofing?

Yes, some related tradies such as tilers, bathroom renovators and even builders are licensed to carry out waterproofing work. Still, if you can choose, it’s better to find a dedicated waterproofing specialist. Qualified specialists will typically have a Certificate III in Construction Waterproofing.

Waterproofing is often included in the tiling or the bathroom renovation quote, although this is worth checking with your tradies.

Remember: whichever qualified tradie does waterproofing work for you, they must provide you with a compliance certificate and warranty upon completing the job.

Only the tradies who hold a current waterproofer licence can legally undertake the waterproofing work in Queensland and New South Wales.

Always make sure the trade professional you engage is insured and don’t forget to check their accreditation and registration. You can do that by referring to the relevant Australian local licensing body:

Now that you know what are your local licensing requirements and how to check your tradie’s licence online, you’re ready to move on to some other burning questions on the topic.

Image from Pexels

Are Tiles Waterproof?

Now that you’ve realised how critical waterproofing is for your bathroom and the whole dwelling, you might be wondering whether the tiles are waterproof or you need additional waterproofing for the peace of mind.

Tiles are water-resistant but NOT waterproof.

Wait, there’s a difference? Confused now?

Don’t worry. It’s a common misconception.

Here’s the truth.

Tiles can help your bathroom walls and floors resist water penetration to some extent and stay protected from water damage, but tiling alone is NOT enough for FULL protection if a water membrane hasn’t been applied before laying the tiles.

Another issue here is the grout sealing the gaps between your bathroom tiles, which is also water-resistant to a certain degree but still allows water to go through the walls and floor.

So, only waterproofing your bathroom can totally block water penetration to the surrounding areas.

Image from Flickr

But you’ve already got tiles laid with no prior waterproofing. Or your old waterproofing system has failed.

What to do now? Is it too late for waterproofing? Can you waterproof over tiles at all?

Here comes the answer.

Can You Waterproof over Existing Tiles?

Applying a waterproof membrane over the existing tiles might perhaps be theoretically possible, but only if the tiles are in a good condition and not loose or cracked. Still, doing it this way, your bathroom will NOT be fully waterproofed.

If the tiles have been installed and you’ve experienced a water leak or damage, it’s better to remove the tiles first and then to properly waterproof your bathroom walls and floor before laying new tiles.

Starting from scratch may sound tedious to you?

Perhaps you think applying a sealer onto the grout joints could help?

Well, it might but it won’t actually waterproof your bathroom.

Make sure you avoid more serious and costly damage by having the job done professionally.

Image from

What Is the Cost of Bathroom Waterproofing in Australia?

For a standard bathroom, you can expect to pay around $600 to $800 for a complete waterproofing job. For second storey bathrooms, which require floor waterproofing, you can expect this cost to rise.

On the other hand, you can expect the cost to lower if packaged with your tiling job or part of a larger renovation involving multiple rooms eg. ensuite, main bathroom, kitchen renovation or even the entire home renovation. Remember?

Image from

We cannot stress enough the importance of hiring a professional to do your bathroom waterproofing. Unlike other jobs which could potentially be DIY’d, an amateur waterproofing job could cost you thousands of dollars down the track when a leak comes through.

Serious structural damage can be caused by poor waterproofing, so hiring a reliable, well-reviewed professional is also a MUST. lets you check reviews of local professionals and compare quotes to find the business that’s right for you. Post your waterproofing job now to start receiving free quotes.

Bathroom Waterproofing Prices from Real Customers

Richie from NSW
He needed waterproofing and tiling done for a bathroom renovation at his Paddington residence. The job was already started, and he just needed someone to finish it.
TOTAL COST: $3,500
Abraham from NSW
He hired a professional to waterproof the bathroom and the kitchen at his home in Tuggerawong.
TOTAL COST: $3,000
Viliam from QLD
He paid for waterproofing and screeding to be done on the shower area of his home in Toowong. The job included tiling the shower floors, bathroom walls, and an extra wall in the hallway.
TOTAL COST: $1,750

Image from Pexels image

What Factors Affect the Cost of Bathroom Waterproofing?

There are jobs that you can do by yourself, but bathroom waterproofing is definitely NOT one of them. It is best left to qualified bathroom waterproofing experts in your area.

In order to prepare for the cost of hiring professionals, you need to understand the factors that can affect the final price of the job.

Besides your location, the foundation, the urgency of your waterproofing project and the problem cause, here’s what else to take into consideration.

What’s Your Bathroom Size?

Since plenty of waterproofing businesses quote on a per-square metre basis, the size of your bathroom will naturally affect the actual cost of the project. The price also depends on whether you want the entire bathroom waterproofed or just a particular area like the shower floor.

What Materials Are Used for Waterproofing?

Liquid-applied membranes are the most widely used waterproofing material for wet areas like bathrooms. Various types of waterproofing membranes include:

  • acrylic,
  • chlorinated rubber or latex,
  • epoxy,
  • polyurethane,
  • polyester resin, and
  • tar epoxy.

When it comes to bathroom waterproofing, there is no clear best option, as it will all depend on the application and other job-specific requirements. Additionally, membranes vary in elasticity, and those with higher elasticity typically offer more protection.

As for the cost of materials, for example, 1 litre of primer can be found at about $17, whereas bond breaker costs around $85 and the other necessary waterproofing materials will set you back $300.

How High Are Waterproofing Labour Costs?

Hiring a licensed waterproofing business may seem costly at first, but it’s definitely a worthy investment. Also, remember that the cheapest quote does NOT necessarily mean it’s the best one for your budget.

By hiring unlicensed or shady tradesmen, your bathroom becomes at risk of being damaged. This is will definitely cost you more in the long run.

That’s definitely NOT what you want, right?

Check out the Service Seeking top-rated bathroom waterproofing specialists who always do the job right at competitive prices.

That’s how you’ll certainly avoid getting ripped off and paying twice for the same job. What’s more, not only will waterproofing protect your bathroom, but the overall value of your house and you’ll be worry-proof.

Disclaimer: Our cost estimates are based on quotes for bathroom waterproofing services and are useful as a guide only.

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There are a lot of qualified bathroom waterproofing experts in your area who can help you. Take a look at’s highest-rated bathroom waterproofing specialists in these major cities: