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A waterproofing membrane is applied to wet areas such as your bathroom to prevent water from leaking into the floor or wall, which can damage your house. The problem with water seepage is that it’s hard to detect until the worst of the damage is done.

You will discover the damage when you see mildew and mould growth, which can cause severe structural damage to the house. Therefore, you can prevent leakage by putting a waterproof membrane, which is a layer of material that doesn’t allow water to seep through.

The article will provide you with in-depth insight into waterproof membranes that you can use to waterproof your bathroom.

Reasons Why You Should Waterproof Your Bathroom
  1. Bathrooms without insulations can contribute to rising damp or the rise of water through walls or floors.
  2. Water leakages can cause warping and rot of beams, joists, bearers, and posts that can jeopardize the integrity of the entire house.
  3. Lack of waterproofing membrane can compromise the light fittings, which can cause electrocution or increase the risk of fire.
  4. Water leaks can cause corrosion of plumbing, and the rusting pipes can contribute to further water leaks.
  5. Mildew and moulds thrive in damp places; thus, leaks can support their growth and spread to other places. Spores from moulds can trigger asthmatic attacks.

Newly bathroom tiling completed in Shepparton (1)

Causes for Membrane Failure

Poor workmanship: The waterproof membrane may fail if the installation is wrongly done, and when you don’t allow it to cure correctly.

Priming: the membrane may fail in cases where the respective parts and surface are not primed before the waterproof membrane is applied. Priming is done to reduce air entrapment, porosity, and dust.

The substrate residual moisture causes the de-bonding of the membrane or adhesive failure. Thus, the concrete slab should be appropriately accessed for moisture content before the application of the membrane.

Cheap waterproofing product has low quality and can fail anytime.

Types of Waterproofing Membranes

Faulty waterproofing is among the top three defects that are reported in Australia. These mistakes are damages the structure just like termites because water leakages are not easily noticeable. Therefore it’s essential to waterproof wet areas like bathrooms, laundries, and kitchen

You should select a waterproofing membrane that is flexible to blend with the shape of the surface it’s laid over, turn up and over walls.

Two waterproof membranes can be used in showers to prevent water leakages.

Liquid Applied Membrane

The waterproof membrane is bought in the liquid from and brush applied or sprayed on the surface. It forms a seamless, joint-free membrane after curing in the air. You can increase the thickness of the layer by applying more liquid in the area.

It is essential to finish the application in the same day to avoid cold joints. The cold joints can be overcome by overlapping the membrane if the contractor can’t complete applying the liquid layer in a single day. The old membrane and the new one will stick easily during the curing process.

The membrane is superior as compared to the sheet-based membrane because it’s joint-free. However, the liquid waterproof membrane can fail if the right thickness is not applied. A thin layer will break or tear over time. Further, the adhesion of the membrane and the surface should be excellent.

You should do sand broadcasting if you decide to apply a concrete layer or tiles on top of the membrane to make the surface hard. This is done when the membrane is wet, and this will make the two surfaces stick together.

Sheet Waterproofing Membranes

There are different sheet membranes available in the market. They are made from a mixture of plastic compounds that are made to stick to the floor or the tile backer board. They have either a peel and stick or thin-tile mortar layer.

You have to apply a primer on the shower pan or backer board before spreading the peel and stick shower membrane. Further, you can use moulded or performed membranes pieces that are sold separately to seal the corners in the bathroom surround.

The durability of Waterproofing Membrane

Waterproofing membrane in bathrooms can last for a minimum of 7 years if correctly applied. Your bathroom will have water leakages when you see signs such as swelling skirting boards, mouldy cupboards, peeling paint, or when the timber under the subfloor, walls, and ceilings may get stained.

You may be tempted to use a silicone sealer that is sold over the counter to fix the bathroom leak. However, these are the short-term solution because it only targets one area, and this can allow moulds to thrive.

Therefore, you should opt for a long term solution instead. You need to remove the tiles and replace the current waterproofing membrane with a superior quality membrane. Contact Shepparton Bathroom Renovators to remove the existing layer and replace it with a new one to improve longevity. It’s recommended that you should use a licensed and accredited tradesperson since most of the waterproofing failures are caused by poor workmanship.

Australian Regulations on Waterproofing

Recent bathroom renovated in Bendigo with porcelain tiles (1)

All waterproofing membranes installation should adhere to Australia standards and building codes A S3740-2010. These general rules are;

Shower floors and walls should be waterproofed up to 1,800 mm height and 150 mm for bathroom walls.

You should waterproof the step between the floor and the shower to prevent water seepage from one surface to the other.

The entire bathroom floor should be waterproofed if it’s not located on the ground floor.

Waterproof the bathroom if it’s constructed with wood.


You should waterproof your bathroom to prevent the leakage of water that can compromise the structural integrity of your property. It is also a requirement by the Australian building standards A S3740-2010

There are two different waterproofing membranes that you can use for your bathroom. However, you can contact Shepparton Bathroom Renovators if you’re struggling to pick the appropriate waterproof membrane for your shower, or none of this makes sense to you. The professional renovators will offer you both internal and external solutions to needs.

Quality waterproofing will minimize frequent maintenance, and this will save you time and money.

Did you find our blog a helpful tool in waterproofing a bathroom? Please visit us at or you may email us at [email protected] or call us at 0491 728 623.

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