How much does bathroom waterproofing cost in Australia?

When renovating your bathroom, there are DIY tasks you can handle, but waterproofing isn’t one of them. It’s crucial to leave waterproofing wet areas to the pros. If there’s a leak, it could lead to various problems like decaying plasterboard, mould growth, rising dampness, peeling paint, and even severe structural damage. Fixing these issues could end up costing you more than waterproofing initially, so it’s wise to ensure it’s done correctly from the start.

This guide will cover:

• Why waterproofing your bathroom is essential
• Key questions to ask before hiring a waterproofing professional
• Expected costs for professional waterproofing services

What is the best way to waterproof a bathroom?

Waterproofing a bathroom is crucial to prevent water damage and maintain the structural integrity of the space. There are several effective methods for waterproofing, each with its own benefits and considerations. Let’s explore some of the best ways to waterproof a bathroom.

1. Waterproof Membranes: One of the most common and effective methods is using waterproof membranes. These are thin layers of material applied to surfaces like walls and floors to create a barrier against water penetration. Membranes can be made of various materials such as PVC, bituminous, or even rubber. They are flexible, durable, and easy to install, providing comprehensive protection against moisture.
2. Sealants and Caulking: Sealants and caulking are used to fill gaps and joints in bathroom fixtures, such as around bathtubs, showers, and sinks. These products create a watertight seal, preventing water from seeping into the surrounding areas. Silicone-based sealants are commonly used due to their flexibility and resistance to mould and mildew. Regular inspection and reapplication of sealants are necessary to maintain their effectiveness.
3. Waterproof Paints: Waterproof paints are specially formulated to resist moisture and provide a protective coating on bathroom surfaces. These paints contain additives that create a waterproof barrier, preventing water from infiltrating walls and ceilings. Waterproof paints are ideal for areas with high humidity levels but may require multiple coats for adequate coverage.
4. Tile and Grout Sealing: Tiles are a popular choice for bathroom surfaces due to their durability and aesthetic appeal. However, the grout lines between tiles are susceptible to water damage if left unprotected. Applying a sealant to both the tiles and grout helps to repel water and prevent moisture absorption. Sealants should be reapplied periodically to maintain their effectiveness, especially in areas exposed to water regularly.
5. Sheet Membranes: Sheet membranes, also known as waterproofing membranes, are thick, flexible sheets made of materials like rubber or polyethylene. These membranes are applied beneath tile installations to create a waterproof barrier. Sheet membranes are particularly effective in wet areas such as shower enclosures and bathroom floors. They offer excellent protection against leaks and can withstand the movement of building materials.
6. Pre-formed Shower Trays: Installing pre-formed shower trays can simplify the waterproofing process in shower areas. These trays are made of materials like fibreglass or acrylic and come with built-in slopes to direct water toward the drain. By using a pre-formed shower tray, you can ensure proper drainage and minimize the risk of water pooling on the bathroom floor.
7. Proper Installation Practices: Regardless of the waterproofing method chosen, proper installation is essential to ensure effectiveness. This includes thorough surface preparation, correct application of materials, and attention to detail in sealing joints and seams. Hiring a professional contractor experienced in bathroom waterproofing can help ensure the job is done right the first time.

Can I waterproof the bathroom myself or should I hire a professional?

Waterproofing a bathroom in Australia is not just a good idea—it’s the law. It’s mandated by the Building Code Australia (BCA) and must comply with Australian Standard AS3740. Here are the basic requirements:

• The floors of shower enclosures must be fully waterproofed.
• Walls of shower enclosures should have waterproofing up to a height of 1800mm.
• Bathroom walls need waterproofing to a minimum height of 150mm.
• If the bathroom floor is timber, or if it’s on the 2nd floor or higher, thorough waterproofing is a must.
• The area from the shower enclosure step down to the floor should be waterproofed to a height of 100mm.

In New South Wales and Queensland, you need a professional. Anyone handling waterproofing in these regions needs to hold a valid waterproofer’s license.

According to NSW Fair Trading, waterproofing is defined as “any protective treatment of a dwelling to prevent water or moisture penetration, or the protection of wet areas to stop water from escaping.” This could involve applying solid membranes or using methods like brushing or rolling. To obtain this license, individuals typically complete a Certificate III in Construction Waterproofing.

Sometimes, trades like tilers may also be licensed to perform waterproofing tasks.

In other states and territories, while a specific license might not be required, a qualified waterproofer should still furnish you with a compliance certificate upon completing the job. It’s essential to ensure your waterproofer provides you with both a waterproofing certificate and a warranty once the job is done.

So, since some states are not requiring a professional, let’s see if you still want to do it yourself.

DIY Waterproofing:

1. Cost-Effective: DIY waterproofing can be more budget-friendly than hiring a professional. You can save money on labour costs by doing the work yourself. However, it’s essential to consider the cost of materials and tools needed for the job.
2. Flexibility: Doing it yourself gives you the flexibility to work at your own pace and schedule. You can tackle the project in stages, depending on your availability and budget. DIY also allows you to customize the waterproofing process to suit your preferences.
3. Learning Experience: Waterproofing your bathroom yourself can be a valuable learning experience. You’ll gain practical skills and knowledge that can be applied to future home improvement projects. There are plenty of online tutorials, guides, and videos available to help you along the way.
4. Control Over Quality: When you do the waterproofing yourself, you have full control over the quality of the workmanship. You can ensure that every step is done correctly and to your satisfaction. However, it’s crucial to research and follow best practices to achieve effective waterproofing.

Professional Waterproofing:

1. Expertise and Experience: Hiring a professional waterproofing contractor brings expertise and experience to the table. They have the knowledge and skills to assess your bathroom’s specific needs and recommend the most suitable waterproofing solutions. Professionals are familiar with building codes and industry standards, ensuring compliance and quality.
2. Time-Saving: Professionals can complete the waterproofing job more quickly and efficiently than a DIY approach. They have the necessary tools, equipment, and manpower to get the job done in a timely manner. Hiring a professional allows you to avoid potential delays and mistakes that can occur with DIY projects.
3. Warranty and Guarantee: Many professional waterproofing contractors offer warranties or guarantees on their workmanship. This provides peace of mind knowing that you’re covered in case of any issues or defects. Professional waterproofing services often come with assurances of quality and reliability.
4. Complex Projects: For complex waterproofing projects or extensive renovations, hiring a professional is usually the best option. Professionals have the experience and resources to handle challenging situations, such as repairing structural damage or installing specialized waterproofing systems.

Factors to Consider:

1. Skill Level: Assess your own skill level and comfort with DIY projects. If you have experience with home improvement tasks and feel confident in your abilities, DIY waterproofing may be feasible. However, if you’re unsure or inexperienced, it’s safer to leave it to the professionals.
2. Budget: Consider your budget and weigh the costs of DIY versus hiring a professional. While DIY may initially seem cheaper, it’s essential to factor in the potential cost of mistakes or rework. Get quotes from professional waterproofing contractors to compare prices and determine affordability.
3. Time Constraints: Evaluate your time constraints and availability for completing the project. DIY projects can take longer, especially if you’re juggling other responsibilities or commitments. Hiring a professional can save you time and hassle, allowing you to focus on other priorities.
4. Risk of Damage: Improper waterproofing can lead to costly water damage and repairs down the line. If you’re unsure about your ability to achieve effective waterproofing, it’s safer to enlist the help of a professional. They can ensure that the job is done right the first time, minimizing the risk of future issues.

How much does bathroom waterproofing cost?

Well, it can vary, but at the lower end, you might be looking at around $40 per square meter. However, that’s just the starting point.

On average, expect to shell out between $500 and $750 to fully waterproof a standard-sized bathroom. If you’re waterproofing multiple bathrooms or bundling it with a complete bathroom overhaul, you might snag a lower price. Conversely, for larger bathrooms, wet rooms, or bathrooms on higher floors, the cost could climb.

To ensure you’re getting a fair deal and quality service, gather quotes from multiple providers. Ask for detailed breakdowns of what each service includes. While it’s tempting to go for the cheapest option, prioritize reputation over price to ensure thorough waterproofing.

For an accurate cost estimate tailored to your project, reach out to local bathroom waterproofers for quotes. This will give you a better idea of current market rates.

Factors Influencing Cost:

1. Size of the Bathroom: The size of your bathroom is a significant factor in determining the cost of waterproofing. Larger bathrooms require more materials and labour, leading to higher expenses. Smaller bathrooms, on the other hand, may have lower waterproofing costs.
2. Extent of Waterproofing: The extent of waterproofing needed depends on various factors such as the type of surfaces, existing damage, and desired level of protection. Waterproofing a shower area or bathtub enclosure typically costs more than waterproofing walls or floors.
3. Materials Used: The choice of materials for waterproofing affects the overall cost. High-quality waterproofing membranes, sealants, and paints may come at a higher price point but offer better durability and effectiveness. Cheaper materials may save money upfront but could lead to higher long-term maintenance costs.
4. Labour Costs: Labor costs contribute significantly to the total cost of bathroom waterproofing. Hiring professional contractors or waterproofing specialists typically involves hourly rates or project-based pricing. The complexity of the job, skill level required, and local labour rates can all impact labour costs.
5. Preparation and Repairs: If your bathroom requires extensive preparation or repairs before waterproofing, such as fixing leaks, replacing damaged tiles, or repairing plumbing fixtures, these additional tasks will add to the overall cost. Proper preparation is essential for ensuring the effectiveness of waterproofing.
6. Accessibility: The accessibility of the bathroom can affect labour costs. If your bathroom is easy to access and work in, such as in a single-story home with ample space, labour costs may be lower. However, if your bathroom is located in a multi-story building or requires special equipment for access, labour costs may increase.
7. Professional vs. DIY: The choice between hiring a professional contractor and doing the waterproofing yourself also impacts the cost. DIY waterproofing may save money on labor costs but requires purchasing materials and tools. Hiring professionals may involve higher upfront costs but ensures quality workmanship and peace of mind.

Average Cost Range:

• DIY Waterproofing:
  • If you choose to waterproof your bathroom yourself, the cost can range from $200 to $500 or more, depending on the materials and tools needed. DIY kits for waterproofing membranes, sealants, and paints are available at home improvement stores and online retailers.
• Professional Waterproofing:
  • Hiring a professional waterproofing contractor typically costs between $500 and $2,000 or more, depending on the size and complexity of the project. This cost includes materials, labour, and any additional preparations or repairs required. Prices may vary based on location, contractor reputation, and project specifics.

Additional Considerations:

• Warranty and Guarantees:
  • Some professional waterproofing services may offer warranties or guarantees on their workmanship, providing added value and peace of mind. Be sure to inquire about warranty terms and coverage before hiring a contractor.
• Long-Term Savings:
  • Investing in high-quality waterproofing materials and professional installation can save you money in the long run by preventing water damage and costly repairs. Properly waterproofed bathrooms are more durable and resistant to mould, mildew, and moisture-related issues.
• Get Multiple Quotes:
  • When hiring a professional waterproofing contractor, it’s advisable to obtain multiple quotes from different providers. This allows you to compare prices, services, and reputation to ensure you’re getting the best value for your money.

Please note, the costs mentioned here were accurate at the time of writing, but they can vary depending on your location and market conditions. Always use them as a rough guide and consult local professionals for precise quotes.