To spray or not to spray!?

When it comes to GRC, there are two basic processes: ‘wet cast’ or ‘spray up’. Wet cast is the most popular for beginners as very few tools other than a bucket and a paddle mixer are needed to get started, however wet cast is also used extensively by professionals for convenience and consistency of surface finish. Wet casting is also used to make cast-in-place (insitu) benchtops directly on kitchen cabinets “face up”. While this avoids the hassle of transporting and installation, it can be a messy process! Spray up or Precast GRC, on the other hand, moves all of the processes off site into a controlled environment like your garage or workshop. You can take your time building moulds and closely monitor the curing process which is critical!

In order to spray GRC you’ll need a few more specialist tools such as a face coat spray gun, along with an air compressor etc. Typically sprayed GRC is built up in 2 stages: a thin “mist coat” is sprayed first and provides the surface appearance, followed by a “backer coat” which has the fibre mixed in.