If you’ve been walking around your neighbourhood, you’ve probably noticed a lot of modern, smooth-walled houses. You might have wondered, “Is that rendered brick?” The answer is: probably not. More often than not, those sleek, contemporary homes are built using Blueboard.
If you’re planning a reno, you’ve likely come across this term. But what exactly is it, and why is every second tradie talking about it?
What is a Blueboard?
Hardie™ Tex Base Sheet (Blue board)
Blueboard is a strong, cement-based sheet used for the outside of buildings that is designed to be covered with a textured render finish. Think of it as the “skin” of a house. It is made from a mix of cement, sand, and cellulose fibres, which makes it incredibly tough and resistant to the harsh Australian sun. The reason it’s called “Blueboard” is pretty simple: the sheets come with a factory-applied blue primer on the front. This blue coating isn’t just for looks; it helps the render (the sandy, paint-like finish) stick to the board properly.
In the past, if you wanted a smooth, rendered look, you had to build a whole wall out of bricks and then hire a plasterer to render over the top. Blueboard lets you skip the heavy brickwork. You just nail these sheets to a timber or steel frame, and you’re ready to go.
Here are the most common ways Aussies use it:
Upper-Floor Extensions: If you’re adding a second storey to your home, bricks are often too heavy for the existing foundations. Blueboard is much lighter, making it perfect for “popping the top” of a house.
Fencing: Want a solid, rendered wall for a fence but don’t want to spend a fortune on a bricklayer? Blueboard over a frame gives you that high-end look for a fraction of the price.
Gables and Verandas: It’s great for filling in those triangular sections under a roof or enclosing an old porch.
Modern Facades: It’s used on the front of many new homes to create a clean, minimalist aesthetic.
Is Blueboard Waterproof?
No, Blueboard is not 100% waterproof on its own, but it is highly water-resistant and won’t rot or break down if it gets wet. Think of it like a raincoat. The board itself can handle getting wet during a storm, but for your house to stay completely dry inside, the Blueboard needs to be part of a “system.” This involves:
Sarking: A foil-like paper installed behind the board to stop moisture.
Jointing Tape: Used on the gaps between the sheets.
Render: The final thick coating that acts as the primary seal against the rain.
If you leave Blueboard unrendered and exposed to the elements for months, it won’t “dissolve,” but it might soak up some moisture, which can cause the joints to crack later on. Always aim to get it rendered as soon as possible after installation.
Blueboard vs. Villaboard: Which One Do I Need?
The main difference is where you use them: Blueboard is for the outside of the house, while Villaboard is for the inside (specifically wet areas like bathrooms).
While they are both made of fibre cement, they have different jobs:
Blueboard: Has a rougher surface so that heavy render can “grip” onto it. It’s also thicker to handle the wind and outdoor conditions.
Villaboard: Has a very smooth finish. It’s designed to be tiled over or painted, making it the king of Australian bathrooms and laundries.
The Golden Rule: Never use Blueboard inside a bathroom (it’s too rough) and never use Villaboard as your main external wall (it’s not designed for heavy render).
Blueboard vs. Greenboard
Blueboard is made of cement and goes outside; Greenboard is made of plaster and goes inside.
Greenboard (which you’ll recognise by its green paper face) is just water-resistant plasterboard. It’s great for the walls in your kitchen or behind a vanity, but if you put it outside, it will eventually turn to mush.
Durability: Blueboard is tough and can handle a direct hit from a footy or a heavy hailstorm. Greenboard is relatively soft.
The Core: Blueboard is cement-based, so it’s basically a thin stone sheet. Greenboard is gypsum-based (chalky), which absorbs water much more easily.
Why Choose Blueboard for Your Project?
If you are renovating or building a fence, Blueboard offers a few big wins:
Speed: You can cover a huge area in a single afternoon.
Cost: It is significantly cheaper than hiring a bricklayer and buying thousands of bricks.
The “Look”: Nothing beats that smooth, rendered finish for adding value to a home.
Termite Proof: Since it’s made of cement and sand, termites have zero interest in eating it.
Get Your Blueboard Delivered Today
Installing Blueboard is a job many handy DIYers can take on, but remember that the “finish” (the rendering) is an art form. If you want that perfect, magazine-style look, it’s usually worth hiring a professional renderer once you’ve got the boards up. At Building Supplies Australia Network, we make getting the right materials easy. We stock the widest range of construction supplies, from Blueboard and Villaboard to all the accessories you need to get the job done right. Order online or request a quote today to get your project started.