And other concrete overlay questions.

One of the most common questions we’re asked as microcement installers is: can microcement be applied over concrete? The answer is yes! Keep reading to find out more about concrete resurfacing with a microcement overlay.

Why install a concrete overlay?

If your concrete is discoloured, damaged, or cracked, you might be thinking about a replacement. Resurfacing concrete with an overlay — like microcement — is becoming a preferred option because it bypasses the need for demolition. Removing the old concrete and re-laying it can be expensive and time consuming, especially if you’re hoping to complete your renovations on a tight deadline.

How does microcement adhere to concrete?

Microcement is a cementitious coating formulated from a mix of stone and polymer bonding agents. There are plenty of microcement products on the market; X-Bond has been our speciality since 1999. It’s formulated with additional latex polymer to create a strong bond at a molecular level over almost any hard substrate. Together with Liquid Membrane, which offers anti-fracture and crack-bridging protection, this system has transformed a wide range of concrete spaces.

Are there joints in microcement?

No, it’s generally applied in seamless joint-free layers — provided a break isn’t required for structural reasons. For example, if there is an existing expansion or control joint in your concrete slab, our installers will replicate this with a thin saw-cut. The saw-cut allows for movement through the X-Bond, minimising the risk of hair line cracks.

Will microcement crack if the substrate moves?

Not all microcements are created equal. It’s true that overlays can be prone to cracking if their formulas are too rigid to withstand the rigours of a naturally moving substrate. That’s why engineers made flexibility a priority with X-Bond. It’s an extremely flexible material, meaning it will resist cracking as the substrate expands or contracts in the event of temperature fluctuations or natural settlement. In 25 years of installing X-Bond Microcement in Melbourne, we’ve never had a delamination issue, either.

Does microcement look the same as concrete?

Microcement products like X-Bond were invented as a concrete alternative, so the final surface can provide you with a very similar look — especially if you choose X-Bond Micro or X-Bond Natural Concrete. There are also a wide range of options for customisation; X-Bond is available in 10 different colours, with the ability to create custom shades too.

How much height does microcement add to a concrete floor?

You don’t have to worry about any extra height on top of your old surface. X-Bond Microcement is applied at 2-3mm thick, a truly seamless option for replacing concrete. It won’t impact door heights and thresholds, or load-bearing capacity.

Can you install microcement on damaged concrete?

Yes, you can resurface cracked or chipped concrete with microcement. X-Bond’s installation process involves a unique step of preparation: the application of Liquid Membrane, a waterproofing and anti-fracture membrane in one, that can bridge small cracks to prepare a strong base for the microcement overlay. For more extensive damage, our installers can restore concrete to the condition needed for effective X-Bond application.

What kind of concrete surfaces can you install microcement on?

Microcement can be applied to existing concrete floors, walls, and ceilings. A key difference is that, unlike other overlay systems, X-Bond can be used both internally and externally — whereas most other concrete resurfacing products can only be used for one or the other. Due to its hand-applied installation, microcement can also be used in more intricate resurfacing jobs including concrete staircases, joinery, and pool copings. X-Bond can be installed over underfloor heating, which is the most common heating system used for concrete flooring.