Re: How to install a shower cabinet?

Wallenberg

Hi Community,

I'm planning a DIY shower installation in the downstairs laundry in my home located in Perth and wanted to reach out to the community for some general advice before I get too deep into it.

This is my first time doing a full shower install from scratch and I want to make sure I understand all the core requirements from a DIY perspective, assumuing the installation (e.g waterproofing) other than plumbing works can be done as a DIY project.

Some points of what I'm working with:

I’m starting from the subfloor and painted brick walls in existing laundry —no drywall, no plumbing yet or though a floor drain is nearby and existing plumbing in adjacent existing toilet is available.

I’ll be installing a prefab shower base + wall kit (not doing tile).

I’m reasonably handy, but I know plumbing and waterproofing can be tricky.

Things I’m wondering about:

How precise does the drain location need to be for a prefab base? Can I fudge it an inch or two if needed?
Since I'm considering a prefab unit, do I still need to waterproof behind the walls? Or is the kit sealed well enough?
If waterproofing is required behind prefab unit, what is the preferred method? The existing wall is brick so no plaster in sight.
Any common things people forget to do that could cause problems with inspection (or just long-term use)?
Any tools or materials you wish you had when you did your install?

I’m trying to plan everything out before I start cutting/drilling so I don’t get halfway in and realize I missed something critical.

Appreciate any tips, lessons learned, or even resources you recommend (videos, guides, etc).

Thanks in advance!

MitchellMc

Welcome to the Bunnings Workshop community @Wallenberg. It's terrific to have you join us and many thanks for your questions on installing a shower.

It’s best to check with your local council or building authority to confirm whether waterproofing can be done as a DIY project in your area or if it must be signed off by a qualified waterproofer.

The drain location for a prefab base needs to be very precise and directly beneath the outlet in the base. There may be limited adjustment possible, but if you are even 50mm off, there is usually not enough space under a prefab base to divert the pipe to the correct position. Ideally, it should line up exactly, although some bases may allow for a flexible coupling depending on the design.

If the prefab unit has sealed wall panels, you generally will not need to waterproof behind them, as they are designed to form a watertight enclosure. However, you will still need to comply with building codes, which often require waterproofing to extend beyond the shower area, across the bathroom floor and partially up the walls.

Given that your existing walls are painted brick, it could be worth considering cladding them with fibre cement sheeting. Battening out the brick and installing fibre cement sheeting over the entire room would give you a clean surface to waterproof and a solid base for your shower installation. Once waterproofed, you can position your prefab unit in the corner.

It would also be a good idea to check out these step-by-step guides and videos on waterproofing and shower installation, as they walk through the process clearly and can help you visualise how everything comes together before you begin.