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Why bathrooms get water leaks in Sydney

Watch this video to see how incorrect tiling and waterproofing caused water leaks in this bathroom in Sydney

The main causes of bathroom water leaks in Sydney

We explain the most probable cause of your leaks

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Nu-Trend is a bathroom renovator in Sydney that are also licensed plumbers who can diagnose and repair bathrooms that have a water leak. In the video above we demonstrate one of the biggest causes of water leaks in bathrooms which is incorrect room preparation during a renovation. 

We normally discover this in two scenarios;

  • The home owner tried to do a DIY bathroom renovation but didn’t follow every specific step required and therefore the bathroom wasn’t water tight.
  • A home owner paid renovation contractors to do a bathroom renovation in Sydney but either chose the lowest quote they could find which meant the contractor used inexperienced labour or was cutting corners on materials or the time put in to build the bathroom.
  • The renovation contractor deliberately built the bathroom incorrectly and did not follow Australian Standards or Building Codes to save time and money.
This is the reason why some complete bathroom renovations might cost $10,000 in labour and others cost $20,000. 

To demonstrate this, the owner of this home had a leaking ensuite bathroom which had been given a cheap renovation. As you can see though it wasn’t done correctly;

  • There was no render on the brick wall
  • The tile is spot glued direct to the brick with no sub surface
  • There was no water proofing
  • The sheeted walls were Gyprock and not fibre cement sheets, these didn’t have water proofing either
So while this bathroom looked ok it wasn’t renovated correctly, wasn’t built to Australian Standards and obviously was causing a water leak in the downstairs area of the home. The bathroom had large format tiles on the walls that could have fallen and injured someone as they entered the bathroom.
So while it is possible to get cheap bathroom renovations what you can’t see or determine is where or how costs are cut to deliver the low cost bathroom renovations that people promote in Sydney. 
This problem often arises when bathroom renovators overlook crucial preparatory steps such as proper floor and wall preparation, including wall sheeting and waterproofing, before proceeding to tiling. Understanding the reasons behind these water leaks and the correct process for installing new tiling is vital in ensuring the longevity and safety of a bathroom renovation.
While it didn’t happen in this situation the water that was leaking in the ceiling cavity could have weakened the bearers in the ceiling or even the Gyprock roof sheeting of the rooms below and lead to them collapsing and falling onto people in the room below. The other consideration for safety would have been the build up of mould as the water sits in areas that it can’t drain or dry quickly.
Therefore this isn’t just about a bathroom renovator trying to make more money, it is a set of standards that should be followed to keep people safe and reduce damage to property.

Reasons for Water Leaks in Sydney Bathrooms:


As a licensed plumber in Sydney these are the most common reasons that we discover for bathroom leaks;
  • Inadequate Waterproofing: According to the Australian Standard AS 3740 – Waterproofing of domestic wet areas, waterproofing is a critical step in bathroom renovation. Skipping this step or improper application can lead to water seeping through to the underlying structures, causing damage over time.
  • Incorrect Wall Sheeting Installation: Before tiling, walls need to be prepared with suitable sheeting that can withstand moisture exposure. The National Construction Code (NCC) and Building Code of Australia (BCA) specify the requirements for wall sheeting in wet areas. Failure to adhere to these can result in moisture penetration, leading to deterioration of the wall structure and the growth of mold.
  • Poor Tile and Grout Application: Tiles and grout must be applied correctly to create a watertight seal. Incorrect tiling practices can leave gaps and cracks, through which water can escape.
  • Faulty Seals Around the Bathtub or Shower Tray: Over time, the sealant can deteriorate or crack, allowing water to seep through.
  • Cracked Tiles or Grout: Cracks in tiles or grout lines can allow water to penetrate beneath the surface.
  • Leaking Plumbing Fixtures: This includes leaks from the sink, bathtub, shower, or toilet, often due to worn out washers or seals.
  • Damaged or Deteriorated Waterproofing Membrane: A compromised waterproofing layer beneath the tiles can lead to leaks.
  • Poorly Installed Plumbing: Incorrect installation of pipes and fixtures can result in leaks.
  • Worn Out Shower Door Seals: Over time, shower door seals can become worn and fail to prevent water from escaping the shower area.
  • Blocked Drains: Blockages can cause water to back up and leak around the fixtures.
  • Loose or Leaking Pipe Connections: Connections that have become loose over time or were never properly tightened can lead to leaks.
  • Damaged or Corroded Pipes: Old or corroded pipes can develop leaks.
  • Inadequate Caulking or Sealing Around Bathroom Fixtures: Insufficient caulking around sinks, toilets, and bathtubs can lead to water seepage.
  • Overflowing Sinks or Bathtubs: Sometimes leaks are simply due to water overflowing from sinks or bathtubs where the water will pour onto the floor, most will go down the waste drain but some of it might get into cracks in the floor or wall tiling that you don’t see straight away.
  • Condensation Build-Up: Excessive condensation in poorly ventilated bathrooms can sometimes be mistaken for leaks because you will see a pool of water on the floor or mouldy spots on the walls.

How should wall tiles be installed in a bathroom in Sydney to prevent leaks?

While we have demonstrated there could be numerous causes for a water leak in a bathroom, let’s focus on the tiling as this was the problem for the bathroom we featured in the video above. Whether we are engaged as a bathroom renovator or called out as a plumber to inspect or find a leak in a bathroom these are the steps we suggest that are taken to reduce the chance of a water leak caused by the incorrect installation of new tiling.

1. Initial Assessment: Before any work begins, assess the bathroom for any existing moisture damage or structural issues. This is important for determining the extent of preparatory work required.

2. Wall and Floor Preparation: According to the BCA and NCC, surfaces must be clean, dry, and free of contaminants. Wall sheeting suitable for wet areas, such as cement sheeting or water-resistant plasterboard, should be installed as per manufacturer instructions and relevant standards.

In a recent job we found loose rubble under a foundation, read the story here and we explain why floor preparation is critical 

3. Waterproofing Application: This is a crucial step that must be executed meticulously. AS 3740 specifies that waterproofing membranes must be applied to the entire floor, the lower section of the walls, and in specific areas such as around the bath and shower recess. All joints and junctions should be treated with a waterproof bond breaker. This should also be signed off by a licensed waterproofer in Sydney.

4. Tiling: Once the waterproofing is cured, tiling can commence. The choice of adhesive and grout should be appropriate for wet areas. Tiling should be done carefully to ensure there are no gaps or uneven surfaces. Grout should be applied evenly, filling all joints thoroughly.

It’s important to also consider that tiling must also focus on applying the right adhesives to ensure each piece has a solid bond to the wall. A shortcut is to use small patches of adhesive rather than covering the entire back of the tile. This can cause movement later on.

5. Sealant Application: After tiling, applying a silicone sealant around edges, corners, and where the tiles meet fixtures is crucial for preventing water leakage.

6. Quality Inspection and Testing: After installation, a thorough inspection and possibly a water-tightness test should be conducted to ensure there are no leaks.

Why should bathroom tiling be installed to meet codes or standards?

Yes you might hear tradies in Sydney complaining about all the rules and regulations when it comes to renovating a bathroom. Although lets face it, the reason many of these regulations are in place are to ensure the safety of other humans. In the case of this bathroom the tiles could have easily fallen off the walls and the water leak could have led to a collapse of the ceiling below it.

The correct preparation of floors and walls, including proper waterproofing and tiling, is essential in preventing water leaks in Sydney bathrooms. Compliance with the BCA, NCC, and AS 3740 not only ensures a high-quality renovation but also safeguards against future structural and health issues. 

Hiring experienced and knowledgeable bathroom renovators who understand and adhere to these standards is crucial for any successful bathroom renovation project so that you can have;

  • Durability and Longevity: Properly executed tiling and waterproofing extend the life of the bathroom, reducing the need for frequent repairs.
  • Health and Safety: Prevents the growth of mould and mildew, which can pose health risks.
  • Legal and Compliance: Adherence to the BCA, NCC, and AS 3740 ensures that the renovation meets Australian legal standards, avoiding potential legal issues and penalties.

How can you identify the cause of a leak in your bathroom in Sydney?

Discovering a leak in your bathroom can be a distressing experience, often leading to concerns about damage and the costs of repair. Identifying the source of the leak is the first critical step towards resolution. In Sydney, where homes vary from historic to modern builds, the causes of bathroom leaks can be diverse.

How to identify these leaks and why involving professionals like Nu Trend, who have licensed plumbers in Sydney, is essential and this is why;

Common signs of a bathroom water leak

  • Water Stains: Look for water stains on the ceilings below bathrooms or on the walls adjacent to showers and bathtubs.
  • Musty Smells: A persistent musty odour can indicate hidden mould growth due to moisture.
  • Loose Tiles or Peeling Paint: These are often signs of moisture issues behind walls or beneath flooring.
  • Increased Water Bills: An unexplained spike in water bills might indicate a hidden leak.

Identifying the cause of a bathroom leak in Sydney can range from a simple visual check to more complex investigations. While some issues can be spotted and addressed by homeowners, many leaks require professional attention. Nu Trend’s licensed plumbers in Sydney offer the expertise and technology necessary to accurately identify and resolve these issues, ensuring your bathroom remains a comfortable and safe space. 

If you suspect a leak in your bathroom, don’t hesitate to reach out to Nu Trend for a thorough and professional inspection. 

We are a bathroom renovator in Sydney that has completed thousands of bathroom renovations.

Nu-Trend has been operating since 2009 as an independent bathroom renovation and plumbing contractor in Sydney. Rick and his team provide a wide range of services for home owners in houses, units, apartments or businesses.

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