One of the multiple benefits of designing landscape or architectural elements in precast concrete is the ability to achieve many different aesthetic styles. Precast concrete as a construction material offers a plethora of customisation options. This article will focus specifically on the different types of concrete finishes available, which play a big part in the appearance of the finished product.
What types of concrete finishes are available?
Pictured above from left to right, the five standard finishes offered by Anston are an off-mould finish, shot-blasted finish, honed finish, polished finish and buffed finish. Our most popular surface finish is a shot-blasted finish, especially in our paving and pool coping product ranges.
Read on to learn the defining characteristics of each of these different types of concrete finishes.
Off-Mould Finish
An off-mould, or off-form, finish is the resulting finish after a precast concrete product is stripped (taken out) from the mould that it was cast in. No further surface treatments are applied, and the off-mould finish is typically very smooth to the touch. There may be some small, visible pockmarks from little air bubbles in the concrete mix.
The off-mould finish is a budget-friendly option that does not compromise on the visual appeal of a precast concrete product.
Shot-Blasted Finish
We have found the shot-blasted finish to be the most popular finish among our client base, as it’s highly suitable for all product applications including precast concrete furniture, paving, planters and bollards.
The shot-blasted finish is created by blasting the surface of the product using very small steel shot or recycled glass fragments, which removes the smooth top surface of the product and creates a rough, textured finish. This technique typically exposes the stone or aggregate material within the concrete mix, creating an additional design detail.
An advantage of opting for a shot-blasted finish is the ability to customise the level of blasting between a light, medium or heavy blast. Light blasting means that only a little bit of the smooth surface is revealed, whereas the heaviest blast will create the most textured surface and expose a lot of the stone aggregate detail. The example image below shows the resulting effect to a concrete product that has been subjected to different levels of blasting.
Honed Finish
The honed finish is used in applications where a smooth, even concrete surface is required, as well as the visual detail of an exposed aggregate finish.
To achieve a honed concrete finish, the product must first be shot-blasted to remove the top surface layer, and then ground down further using a grinding disc to produce the smooth surface. Due to the additional labour required, honed products are more costly than off-mould or shot-blasted products and will incur additional lead times for production.
Honed products are less slip-resistant than products with our shot-blasted finish, and this surface finishing option is not available on our pool coping range.
Polished Finish
To add some sparkle and shine to a concrete product, a polished finish is the way to go. A polished finish is achieved by applying an additive such as a varnish or resin to a honed product, which adds a clear, lustrous layer to the concrete that makes it even more eye-catching.
Due to the requirements of blasting, honing and then polishing the concrete product, a polished finish is the highest priced option and also incurs the longest lead times. However, the result is definitely worth it!
Polished products are less slip-resistant than products with our shot-blasted finish, and this surface finishing option is not available on our pool coping range. It is also less popular for paving products.
Buffed Finish
A buffed finish is not as popular as some of the other concrete finishes already mentioned, but is no less appealing for customers looking for an authentic concrete style.
The term buffing refers to treating an off-mould concrete surface with a polish additive, resulting in extra protection of the concrete and adding a lustrous shine.
Buffed products are less slip-resistant than products with our shot-blasted finish, and this surface finishing option is not offered in our paving and pool coping product ranges.
Slip Resistance of Special Concrete Finishes
All Anston concrete finishes are rated Class 1 as per the Australian Standard 3610. Apart from our polished and buffed finishes, which achieve a P4 slip resistance rating, all other Anston surface finishes achieve the highest slip resistance rating of P5 (wet pendulum test).
Slip resistance ratings are relevant for products such as paving, pool coping and stair treads, as these products are subjected to foot traffic. Customers can rest assured that our precast concrete products achieve the highest slip ratings where required, ensuring safe, trafficable surfaces for pedestrians.
What’s Next?
Now that you know all about the available concrete finishes from Anston, it’s time to start designing your unique product! Our team can assist if you would like some guidance on which type of concrete finish would be most appropriate for your project.
Take a look at our project gallery for some inspiration, or contact us if you’d like to discuss your design concept with an Anston representative.