Easy, Step-By-Step Guide To Waterproofing A Bathroom in NZ

26th Nov 2022

Easy, Step-By-Step Guide To Waterproofing A Bathroom in NZ

Building or renovating your bathroom is an important project that needs to be done right. The last thing you want is moisture damage from improperly waterproofing your bathroom

At Tile Space, we don’t just have the materials you need to get the job done. We are dedicated to  offering expert advice for every tile project.

Read on for our guide that answers the five most important questions you may have about waterproofing your bathroom.


Here’s what’s covered,


Do you need to waterproof a bathroom floor in NZ?

Bathroom floors should be waterproofed to avoid water damage to the structure of the house. This is not only essential to keep your home in good condition, but  it is a requirement of New Zealand’s building code.


Do I need waterproofing behind shower tiles?

Yes, bathroom waterproofing requirements in NZ state that the membrane must extend under and up the walls behind bathtubs, sinks, and showers.

As the bathroom is a major wet area of the house, the floor needs to be capable of holding water.

Bathroom floor and wall tiles are impermeable, but cement-based grout does not prevent water seepage.

White tiled bathroom

Super White Mosaic | Super White Decor | $20 to $25 per sheet/s


Do I need to waterproof walls before tiling?

The walls in your bathroom and other wet areas should be waterproofed in any rooms fitted with pipes.

Waterproofing methods are more effective before the tiles are laid. Our recommended bathroom waterproofing product in New Zealand, Wedi, is installed behind tiles.

Related Guide:  Bathroom Tile Beginner's Guide


What happens if you don’t waterproof bathroom walls? You don’t want to find out!

Bathroom walls are vulnerable to dampness due to water leaking from faulty pipes or permeating through the tiled surface.

Moisture, even in the form of steam, passes through the grout and creates dampness inside walls. This eventually damages the structural integrity of the house.

Bathroom walls should be waterproofed all the way up behind shower spaces. These sections can then be tiled like the other wall spaces. Check out our recommendations for some gorgeous tiling trends to get an idea of grouting.

White and black tiled bathroom

Luxe White Matt | Luxe | $85 to $115 per m2


How do I completely waterproof my bathroom?

To ensure your bathroom is fully sealed and watertight, you need to apply a liquid sealant to tiles on the shower wall and floor - this is a protective barrier to stop water from breaching the surface.

You also need to have silicone sealant applied to gaps between the wall and floor joints. Overall, these combined sealants help completely waterproof your bathroom.


What are the best products for bathroom waterproofing?

Wedi bathroom waterproofing

Tile Space is proudly the exclusive NZ stockist of Wedi waterproofing systems. Easy to install and customise, Wedi systems create a strong and impermeable membrane that can be installed within just 3 hours!

They are backed with Codemark certification and BRANZ appraisal ready for NZ use.


Top Benefits:

A 3-in-1 waterproofing solution- that replaces plasterboards, screeds, and waterproofing membranes

Lightweight - easy to transport and install

✓ Shortens installation time from 3 days to 3 hours

100% waterproof and mould-proof shower system

✓ 15-year full replacement warranty


Wedi Waterproofing Systems


Can I do waterproofing myself?

Yes, you can waterproof your bathroom on your own as long as you follow the NZ Code of Practice for Internal Wet-area Membrane Systems. Using the Wedi waterproofing system would make waterproofing quicker and more convenient.

This membrane is crafted by experts so it can be used by home renovators with little to no experience.


Step-by-Step Guide to Waterproofing Your Bathroom

  1. Cut the Wedi board to fit the wall surface. Pieces can be joined using joint sealant.
  2. Fasten the board to the wall and floor surfaces using Wedi fasteners.
  3. Use a putty knife to spread the sealant over any joints.
  4. Perform a water test after a minimum of 2 hours to confirm that the waterproof membrane is watertight.
  5. Lay the tiles or other finishings on the waterproofed surface. Take a look at a few of our tile ideas for a modern finish.

For more detailed installation tips, download the Wedi Spa & Shower Systems Brochure.

Wedi is not only a superior quality waterproofing membrane, but it also boasts a rapid drying time.

This means it is ready to tile over in a matter of hours while most other waterproofing bathroom products take over 24 hours to be ready.


How many layers of waterproofing do I need?

Wedi building panels are applied in a single layer. This easy application is possible because the board itself is comprised of multiple essential layers.

Cement resin surface Blue XPS core
  • Serves as a high-quality bond surface for any tiles or tile adhesives.
  • Ensures a completely waterproof finish
  • Reinforced with embedded fiberglass mesh on both sides


At Tile Space, we are proud to offer you great products and excellent advice.

For fast, easy, and reliable waterproofing in New Zealand, Wedi is just what you need. Shop with us today to create your ideal bathroom.


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