Overlays can be added to concrete surfaces to hide imperfections, to give them additional protection or to improve the aesthetics. There is a huge range of different types of overlay to choose from, so you can select the perfect one for each setting and requirement. They are designed to adhere perfectly to prepared concrete to provide a great finish. If the preparation is not done or does not meet the right standards, it can result in poor adhesion. Ultimately this can lead to delamination and early failure, underlining the importance of careful preparation.
The first step when preparing the surface is to clean it to get rid of any contaminants that would interfere with the adhesion. Substances like dirt, oil, grease and chemicals all need to be removed. Any old paint and sealant needs to be cleaned up too, including any markings that will prevent a smooth, even finish.
The second step is to inspect for any areas where the concrete is no longer sound including patches of spalling, scaling or delamination. Each of these will make adhesion tricky when the overlay is added, so they need to be dealt with. The best solution is to remove the damaged concrete to leave a solid surface.
Once this is done it will be easier to see whether there are any cracks on the floor or patches which need to be filled. Overlays can cover many small imperfections but larger damages will require repairing first because they will show through. Generally cracks which are over three inches wide should be filled and levelled off before moving on.
The final stage before adding the overlay is to profile the concrete. Overlays adhere better to roughened surfaces than completely smooth ones because they will have something to grip on to. The whole surface will need to be profiled right up to the edges to make sure there are no areas with poor adhesion.
There are a number of different ways to prepare a concrete surface for an overlay. Sand and shot blasting are amongst the most popular techniques because these methods can remove contaminants, broken concrete and add texturing. This can speed up the project but care needs to be taken to ensure that the job is done correctly.
At Churchill Concrete Technology we can provide a flexible service to prepare all kinds of concrete surfaces. Our team is highly skilled and capable of completing concrete repair and preparation jobs safely, efficiently and to a very high standard. If you would like further information or tips please contact us.