Taking care when finishing sprayed concrete

The sprayed concrete technique revolutionised the construction industry, making a time consuming task much faster. Rather than troweling all of the material by hand or pouring it, the spraying equipment means it can be quickly fired at a surface. It is then a case of smoothing it down and getting the relevant finish.

When finishing sprayed concrete it is important to not disturb the impaction bond. This can result in premature failure of the material. The thinner the coating the less pressure should be used during finishing to prevent damage to the impaction bond. The only time this will not be the case is if a mix with polymers has been utilised as it will have much higher bonding potential.

Typically it is best to leave sprayed concrete finishes as they are to prevent the bond problems. Light troweling can be done as long as suitable tools are utilised. Wooden ones are best but a steel float can be utilised if care is taken.

Generally troweling is easier when finer aggregates have been used in the concrete mix. It becomes more challenge to smooth the surface effectively with larger ones as slight movements can ruin other parts of the surface.

If you do finish a concrete surface that has been sprayed you need to avoid adding additional water. This could cause big problems as the moisture content in the mix has been carefully calculated to ensure it will stick and set. Adding more water can compromise this and leave the material taking longer to dry.

At Churchill Concrete we have a lot of experience with sprayed concrete. We utilise the technique ourselves on countless projects, including when we repair surfaces. If you need any advice or want to arrange a professional service we are the company for you. Simply get in touch and we will arrange everything with you.