If you are thinking about overlaying your concrete surfaces, you should plan on performing thorough surface preparation. Often, overlays fail prematurely in numerous properties because the old surface lacks the capability to bond with the fresh material. For instance, if the old concrete is covered with dirt and grease, delamination of the fresh coating will occur. Fortunately, there are multiple types of equipment which you can choose to ensure that the worn out concrete layer is correctly removed, allowing the bonding of the overlay. Here are crucial considerations to help you select the right surface preparation machine. 

Old Concrete Finishing

When choosing your surface preparation equipment, you should consider the type of material finish you would like to eliminate. In simple terms, there are numerous coatings on concrete which limit the bonding capabilities of the old concrete. For example, the surface might have an epoxy, paint or mastic layer. If you have a light coating such as paint, you can utilise lightweight techniques such as shot blasting. However, if you would like to remove epoxy or elastomeric coatings from concrete, you should acquire a concrete grinder or scarifier. 

Thickness of the Worn Layer

You should think about the thickness of the layer you would like to remove from the old flooring. Simply speaking, you should consider the total depth of the worn out layer before choosing your surface preparation equipment. In general, abrasive blasting machines are only suitable for dealing with superficial coatings such as paint. Therefore, if you wish to eliminate a thick layer of concrete and polish uneven areas, you should choose concrete grinding or scarifying. The former option is ideal for most overlay projects because it eliminates finishes and scrapes away the top layer of concrete without going too deep. 

Type of Overlay

Finally, you should ensure that you understand the type of surface profile which is required for your overlay. The goal of surface preparation is to make sure that the concrete has enough 'bite' to promote adhesion of the coating. The level of 'bite' required will vary depending on the specific type of overlaying or coating product you would like to utilise during your project. For this reason, most manufacturers of overlays and other coating products will specify the specific equipment which should be used for surface preparation before the application of their product. Therefore, you should consult your overlay supplier before making a decision.

If you are uncertain about the right surface preparation technique for your overlay project, consult your experienced concrete contractor for advice.