Planning a bathroom renovation can be exciting, but it also comes with a lot of technical questions. One of the most important things to get right is what goes on your walls before the tiles even touch them. If you’re doing a shower, you can’t just use any old wall sheet. You need something that can handle the steam and splashes of a busy Australian household.
What is shower plasterboard?
Shower plasterboard is a water-resistant wall sheet specifically designed for wet areas like bathrooms, laundries, and kitchens. While it looks similar to the standard plasterboard used in bedrooms, it has a special core treated with wax or silicone to stop water from soaking in. In Australia, you can usually spot it by its green or blue paper face.
Think of it as the “heavy-duty” version of standard plasterboard. Because it doesn’t soak up moisture like a sponge, it stays strong and keeps its shape even when the bathroom gets steamy. However, keep in mind that “water-resistant” doesn’t mean “waterproof.” You still need to apply a proper waterproofing liquid (a membrane) over the top in the areas where water hits directly, like inside the shower.
Can you use normal plasterboard in a shower?
No, you should never use standard plasterboard in a shower because it will soak up water, turn to mush, and cause your tiles to fall off. Standard plasterboard is made of gypsum and paper. When it gets wet, the paper peels away and the inside crumbles. This leads to “leaky shower syndrome,” where water gets into your timber house frame and causes expensive structural rot.
Even worse, wet standard plasterboard is a magnet for black mould. Once mould gets behind your tiles, it’s very hard to get rid of and can make your family sick. Using the right water-resistant board from the start is the best way to avoid a “renovation nightmare” down the road. It’s a small investment now that saves thousands of dollars in repairs later.
What are the best materials for bathroom walls?
Siniat Watershield Plasterboard
The two most common materials for Aussie bathrooms are Water-Resistant (WR) Plasterboard and Fibre Cement Sheeting. Both are great choices, but they are used in slightly different ways depending on where you are tiling and how heavy those tiles are.
WR Plasterboard (Green Board): This is the most common choice for general bathroom walls and ceilings. It’s easy to cut, light to carry, and gives you a very smooth finish for the areas you want to paint.
Fibre Cement Sheeting (Villaboard): This is a much tougher, cement-based board. It is almost impossible to damage with water. Most tradies prefer using fibre cement inside the actual shower cubicle because it is stronger and can hold the weight of heavy, large-format porcelain tiles much better than plasterboard.
If you are planning on floor-to-ceiling tiles that are thick and heavy, fibre cement is usually the way to go. For basic walls and ceilings, WR plasterboard is perfect.
What are the rules for waterproofing a shower?
In Australia, you must follow the AS 3740 standards, which require a professional waterproofing membrane to be applied over your wall boards in all “wet zones.” This means that even if you use the best shower plasterboard on the market, you cannot skip the waterproofing stage. The law requires a waterproof seal in the shower up to at least 1.8 metres high.
Waterproofing involves painting a thick, rubbery liquid over the joins, corners, and tap holes of your plasterboard. This creates a “tub” that catches any water that might sneak through your tile grout. In Australia, it is highly recommended (and often legally required) to have a licensed team do this part of the job to ensure your home stays dry and your warranty stays valid.
How do you install shower plasterboard?
To install shower plasterboard, you screw the sheets into your wall studs using special “treated” screws that won’t rust, making sure to leave a small gap at the floor. You want to avoid having the board sit directly on the floor where it might “wick up” any puddles.
When you are putting the sheets up, make sure the joins are tight and land on a timber stud so they don’t move. Instead of using standard “base coat” plaster, you should use a moisture-resistant jointing compound. Once the boards are up and the joins are sealed, you are ready for the waterproofing membrane and then your tiles. It’s all about creating layers of protection to keep the water where it belongs.
Recommended Products for Your Project
Choosing a trusted brand is the best way to ensure your bathroom stands the test of time. Here are the top products used by Aussie tradies:
Siniat Watershield Plasterboard: This is a premium water-resistant board specifically engineered for wet area walls and ceilings. It features a highly moisture-resistant core and is a favourite for its durability and ease of installation.
Siniat TruRock HD: This is the “all-rounder” for high-traffic homes. It is not only water-resistant but also fire-rated and impact-resistant. If you want a bathroom wall that can handle steam while being tough enough to resist bumps and knocks, TruRock is the gold standard.
James Hardie Villaboard: The industry standard for fibre cement sheeting. It is incredibly tough and the best choice for walls that will be carrying heavy, high-end tiles.
Build a Bathroom That Lasts
Don’t be tempted to cut corners with standard materials. Stick to the products designed for the job to ensure your new bathroom stays beautiful and healthy for decades. At Building Supplies Australia Network, we offer the widest range of construction materials at competitive prices. We deliver quality supplies directly to major cities across Australia. Order online today or request a quote.