How to replace a shower floor?

Question

Hello.  I have removed an old 860 x 860 shower and am left with a partial hole in the floorboards in the corner where the old ceramic tray had been.  My objective is to have a linear drain against one wall with a tiled pan made from building up a sloping concrete base by hand and a square rim (hardwood) around the outside, supporting a sheet glass screen on one side.  My idea is to remove a few extra floorboards (some are water damaged but joists are fine) and put down a new wider floor but I'm not sure what to use.  Does anyone have any advice or experience in doing this type of job?  What type of flooring should I use, is hardwood ok for the surrounding lip, what sort of concrete to use, what sort of waterproofing and where, etc?  Are there any online resources anyone can recommend?

MitchellMc · Accepted Answer

Welcome to the Bunnings Workshop community @BigDazza. It's brilliant to have you join us, and many thanks for your question about building a shower recess.

For your shower build, I’d recommend using compressed fibre cement board (also known as fibre cement sheeting) as the substrate for the new floor. It’s a solid and durable option that can handle the wet conditions of a shower area. You should remove the surrounding floorboards and install this fibre cement board across the entire area where the shower pan will go.

The wall should be sealed against the edge of the floorboard with polyurethane sealant. It's important to ensure that your joints are waterproofed properly, which means applying waterproofing tape at the joints and then using a waterproofing membrane over the top of the entire surface. This will help ensure a watertight seal and prevent any future leaks.

For the sloping concrete base, you can screed the concrete to the required slope towards the linear drain. As for the hardwood lip, it could work, but it’s important to ensure it is well sealed and maintained to prevent water damage.

Due to the complexity of constructing a shower from scratch, including the necessary waterproofing and code requirements, I'd strongly recommend consulting a professional to ensure everything is done according to the required standards.

Here's a helpful guide: How to waterproof a shower.

Please let me know if you have any questions.

Mitchell