Do you need to waterproof a laundry?

[Newbie2k23]

Hello all, and thank you in advance.

Im having trouble deciding regarding law about laundry. Some said i need to waterproof the laundry. The tiler said i don't need to waterproof, just water resistant. Can someone please help me with what to do please.

[MitchellMc]

Hi @Newbie2k23,

In the Nation Construction Code 2019 in table 3.8.1.1 (which appears to be still in use in the newer 2022 code) 'Waterproofing and water resistance requirements for building elements in wet areas', it lets you know whether you need to waterproof or if water-resistant flooring will suffice. At a glance, it would appear that in a laundry, only water-resistant flooring is required. I'll include the section below for you to look at yourself. For SA readers, there is an additional section that states if that laundry has a floor waste, it's considered a penetration and waterproofing is then required. 

Also, in the 2022 NCC it states: 

10.2.5 Other areas

2019: Table 3.8.1.1

(1)For walls adjoining other types of vessels (e.g. sink, basin or laundry tub), the following applies:

1. Walls must be water resistant to a height of not less than 150 mm above the vessel, for the extent of the vessel, where the vessel is within 75 mm of a wall (see Figure 10.2.5).
2. Waterproof wall junctions where a vessel is fixed to a wall.
3. Waterproof tap and spout penetrations where they occur in surfaces required to be waterproof or water resistant.

(2)For laundries and WCs, the following applies:

1. The floor of the room must be water resistant.
2. Wall/floor junctions must be water resistant, and where a flashing is used, the horizontal leg must not be less than 40 mm.

There seems to be plenty of information out there that states you must waterproof a laundry with no exceptions. As I'm not an expert on reading the NCC, I encourage you to do your own research and come to the conclusion that you are happy with. It is my opinion that it would be in your best interest to waterproof the floor, even though the code appears to state it isn't mandatory.

Please let me know if you have any questions.

Mitchell

[Newbie2k23]

Thank you for your reply @MitchellMc. What does it mean water resistant for the floor? Our laundry doesn't have floor waste. That's why some said only need water resistant. With the wall , i watched a bunnings video on youtube on how to install villaboard. for the floor, im not sure what water resistant they are talking about

[MitchellMc]

An example of water-resistant flooring would be tiles @Newbie2k23.  

At what stage are you in your project? What is the subfloor made from, is it elevated on a timber frame or on a concrete slab?

Mitchell

[Newbie2k23]

Concrete subfloor. We were nearly finished in the lounge for tiling, and our next will be laundry. That's why i did ask for help because i have to make sure we are doing the right thing before we start tiling the laundry.

[MitchellMc]

If you had a timber sub-floor, it would be more of a concern @Newbie2k23.  With a concrete slab, it appears, according to the code, that no waterproofing is required. So you could use tiles or Hybrid vinyl flooring.

Mitchell

[Newbie2k23]

Thank you so much, @MitchellMc. we will order villaboard and change our wall for it. And we can continue our tiling in that case.