Is waterproofing needed under the shower base?

[charlie01]

I was watching Bunnings' How to Install a Shower Base" video (https://youtu.be/K1889rjISd0?si=bHam5D3Omgzjtbn2) and noticed no waterproofing under the shower base was applied (In the video, there is no shower wall, so I'm not sure the whole plan of the shower). I was wondering whether waterproofing is required under the shower base according to the Building Code. Cheers.

[EricL]

Hello @charlie01 

Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your question about the shower base installation.

Since the demonstration was just about the shower tray installation the other parts of the shower assembly were not mentioned. Its purpose was to show you an example of how the shower tray can be installed.

In regards to waterproofing the National Construction Code is quite clear on the requirement in section Part 10.2 Wet area waterproofing. The floor and walls must be waterproofed before you fix the shower tray in place. I also recommend checking your local council rules and regulations regarding waterproofing as they might have other guidelines that must be observed.

Please note that some states require a registered waterproofing professional to apply the waterproofing in your bathroom before it is signed off. 

If you need further assistance, please let me know.

Eric

[charlie01]

Thanks for the link.

According to the 10.2.2 (2), waterproofing doesn't seem to be required if shower base/pan is used, as it says: "except for (a) which is not applicable."

10.2.2 Shower area (enclosed and unenclosed)

(1) For a shower area with a hob, step-down or level threshold, the following applies:

(a) The floor of the shower area must be waterproof, including any hob or step-down (see Figure 10.2.2); and

(b) The walls of the shower area must be waterproof not less than 1800 mm above the floor substrate (see Figure 10.2.2).

(c) Wall junctions and joints within the shower area must be waterproof not less than 40 mm either side of the junction (see Figure 10.2.2).

(d) Wall/floor junctions within the shower area must be waterproof (see Figure 10.2.2).

(e) Penetrations within the shower area must be waterproof.

(2) A shower with a preformed shower base must also comply with the requirements of (1), except for (a) which is not applicable.

[Explanatory information:

Preformed shower bases are commonly made of plastics, composite materials, vitreous enamelled pressed steel, or stainless steel.]

[EricL]

Hi @charlie01 

It's that first statement (a) The floor of the shower area must be waterproof that tells me that it must be covered. As I understand it the exception refers to the shower base not needing to be waterproofed above as it it is not applicable. But from a practical point of view waterproofing the entire floor area is like an extra guarantee of protection even if you have an impermeable shower tray. Why leave a small area to chance? It's better to have it totally sealed for peace of mind.

If you need further assistance, please let us know.

Eric