A guide covering all your questions about concrete overlay systems, and why they’re becoming an increasingly popular flooring choice among designers, builders and home owners.

What is concrete overlay system?

A concrete overlay system is a thin, cement based coating that is applied directly over an existing concrete slab.  While most traditional overlay systems can only go over concrete, Alternative Surfaces X-Bond overlay system is a concrete overlay that can go over concrete, tiles and compressed sheeting, opening up a world of possibilities for renovators and new home builders.

The reasons a concrete overlay would be required is usually for repair or decorative reasons. You may not like the colour of the concrete, there may be a lot of inconsistency and imperfections in the slab, there may be visual damage from trades and works that have taken place, or you may have major cracking.

The beauty about a concrete overlay system like X-Bond is that you can still achieve a concrete looking aesthetic on your floor, a finish that is more uniform, consistent and can be the correct shade of grey that you were hoping for. 

Does concrete overlay last? 

There are many different concrete overlay systems on the market, and all products have a different lifespan depending on the quality of the product, quality of the sealer and the skill of the tradesman applying the concrete overlay. It’s important to note that an overlay system is only as good as the substrate it’s being applied over, which means that if there is alot of movement throughout your concrete slab, this can transfer through to your concrete overlay by way of hairline cracks. 

X-Bond is one of the most advanced concrete overlays on the market today. Developed by a team of surface engineers in the United States, X-Bond is flexible, strong and has been successfully installed to floors in residential and commercial projects for over 20 years.

How do you make a concrete overlay system? 

A concrete overlay system should be purchased or installed by a professional installer to ensure it’s a quality product that will last a lifetime. Concrete overlay systems usually consist of sand, cement, liquid polymer and colour pigment. These products are all mixed together and hand trowelled over your existing concrete slab at a minimal thickness (usually 3mm thick)

How long does it take concrete overlay to dry? 

For a concrete overlay system like X-Bond, it takes 24 hours after the last coat of sealer for the surface to be able to be walked on with protection. We recommend walking with socks during this time and also protecting your floor as the product will still be curing for a total of 7 days. 

Do concrete overlays crack?

Concrete overlays can crack. Being an overlay system, the concrete overlay follows the existing substrate which means that if there is movement in the concrete slab it’s applied over, this movement can cause cracks which can transfer through to the X-Bond creating hairline cracks. To avoid cracking, Alternative Surfaces have a anti-fracture membrane which is used during the preparation stage to minimise the risk of cracks appearing. 

Another precaution that can be taken to minimise the risk of cracking is placing saw-cuts where there is an existing expansion joint to allow for movement. 

Can you overlay over cracked concrete?

You can install a concrete overlay system over cracked concrete however there are a number of things you need to know before you do.

1. Overlaying over cracked concrete doesn’t guarantee that the cracks won’t appear through the new overlay system. Overlay systems follow the existing substrate which means that cracks can still appear through your overlay.

2. If there is bad cracking, or expansion joints, usually a saw cut or profile can be placed in these areas to allow for movement. Assisting in minimising the risk of cracks appearing through your overlay.

3. There are many different overlays on the market, and you will want to ensure you’re using a durable, quality overlay like X-Bond microcement.

4. An anti-fracture membrane may be recommended by your installer to mask any existing cracks. To find out more about how the anti-fracture membranes work, feel free to contact us here.

How thin can a concrete overlay be?

Concrete overlays are applied at a minimal depth, typically between 2-4mm thick. 

Are concrete overlays durable?

Concrete overlays are not as strong as a concrete slab, as they are a thin coating, however you can get concrete overlays on the market that are very durable and suitable for internal, external, foot traffic and vehicular traffic. This also comes down to the sealer that is used to seal the concrete overlay system. Alternative Surfaces use an industrial strength sealer called ‘Satin Stone’ which is water-based and used for residential and commercial applications.