Whether you’re aiming for the rugged functionality of industrial styles, elegant minimalism, or something more contemporary, concrete is a versatile building material that can function in many different areas of a home and suit a wide variety of design styles. Where it’s featured most often in our builds, though, is as a flooring material. So, let’s take a look at the good, the bad, the types you can choose from, and a few of our trade secrets to ensure a top-notch end product.
THE GOOD
Concrete is one of those materials that seems to stay popular no matter what design style is trending. There are a few good reasons for this.
Thermal mass – Thanks to its thermal mass, concrete helps regulate indoor temperatures and reduce the need for electric heating and cooling. It does this by absorbing heat during the day and slowly releasing it as it gets cooler at night.
Cost-effective – Because the concrete forms part of the home’s structure, it’s often quite a cost-effective choice. There’s no need to pay for extra materials like timber floorboards or carpet, and it requires much less labour.
Incredibly tough – As long as the concrete is properly sealed, you can drop a glass, let your kids run amok or even let them ride their skateboard across it; you might need to give it a quick mop, but dents or long-term damage are much less likely.
Versatile – As a raw product, concrete has a very natural aesthetic that can look stunning in a wide variety of design styles.
THE NOT SO GOOD
As with any other building material, there are some important caveats to consider before deciding whether concrete is the right option for your build.
Cracking – No matter how careful your builders are, concrete floors will almost always develop some cracks. Depending on the finish, though, these may not be very noticeable.
Difficulties with samples – Concrete samples are rarely able to provide an accurate example of how the finished product will look on a large scale, and once it’s installed there’s nothing you can do to change it except pull it all up and start again. So, always be prepared for some variation and make your selections with this in mind.
Damage during construction – Unlike floor finishes like timber and carpet, which are installed closer to handover, concrete is poured during one of the first stages of construction and can be at risk of damage during the rest of the build.
Undulation – In Australia, construction standards allow for up to 30mm of undulation across a slab. This may not seem like much, but it will when you spot a gap beneath your cabinetry or skirting boards that then needs to be addressed.
Once it’s set, it’s set – Once your slab is poured, it’s set in place and there’s not much you can do to change it. This means that services can’t be relocated later, so always triple check their locations before the concrete is poured, and consider including some extra routes just in case.
TYPES OF CONCRETE FLOORS
Concrete flooring can come in a few different finishes, but all begin with a cement slab made from a mix of cement, sand and stone (aggregate). Let’s look at two of the most common options:
Polished concrete
Polished concrete is made by grinding the concrete slab to expose the aggregate within it. Depending on how much of the concrete is grinded down, you can completely expose the aggregate to see large chunks of stone, or aim for a more subtle ‘salt-and-pepper’ finish with only small chunks of the aggregate visible. The finished look can also vary significantly depending on the type of stone used as the aggregate, such as granite, quartz and black stone. After grinding, the floor will then be finished with a sealant to suit your needs and style, such as hyper gloss, matte and non-slip (typically used for outdoor areas like alfrescos). Compared to burnished concrete it tends to result in a more consistent finish.
Polished concrete at Alfred Road.
Salt-and-pepper at Hausen Court.
Burnished concrete
Burnished concrete also starts with a standard concrete slab that then gets ‘trowelled’, a process of heating and buffing a wax-based coating onto the surface. This densifies the top layer of concrete and often darkens it in the process. Be aware that some variation at this stage is virtually unavoidable as the finished look will depend not only on how the concrete has been poured, but also how long the concreter spends trowelling each location. Burnished concrete is typically cheaper than polished concrete because there’s no need to spend extra on specific aggregate mixes.
Burnished concrete at Amherst St.
TRADE SECRETS
If you have a very specific vision for your floor, both polished and burnished concrete can be a bit of a risky choice as variation and minor flaws are almost unavoidable. That said, there are a few tricks we’ve learnt over the years to help provide a more guaranteed finish.
Prep is vital – The preparation of your site and its foundations need to be spot-on before pouring the concrete slab or you increase your chances of a cracked or uneven slab.
Watch the weather – Rain is an obvious issue for wet concrete, but hot weather can also be a problem as the concrete can cure too quickly and become more likely to crack.
Perfect formwork – To ensure a high-quality end product, you need to start with perfect formwork. That’s why we build all formwork to the exact height of the slab, so the concrete can be poured and levelled accurately.
Stronger mesh – To strengthen the concrete slab and reduce the chance of cracking, we use a thicker gauge steel mesh than is typically used in concrete slabs—our go-to is usually SL92.
Check all the services – Once the concrete is poured, services can’t be moved without demolishing the entire slab: check, check twice, then triple check.
Floor heights – If other rooms have a different finish, like timber or carpet, make sure the concrete slab is recessed in those areas to ensure flush transitions throughout your project.
A recessed floor to ensure a small transition between burnished concrete and timber flooring.
Some of our favourite projects
