I realise that this is a render but I’m actually working on something like this at the moment.
The way we’re achieving it is through a material called GRC (glass reinforced concrete). It’s effectively like if you broke your arm and got a plaster cast, but with concrete and fibreglass.
The contractor has been taking on site castings of live rock in a quarry where afterwards he will set up around 10x 1mx1m square molds that we’ll cast the GRC panels from. These are being mounted on the wall in a randomised series of translations and rotations before being site patched to cover the joints and fixing holes and painted.
The actual finishing is done by an artisan in the cinema effects industry rather than the builder.
We’re using GRC as it will feel cold to the touch like real rock, and in some cases we will back fill it with light weight concrete so it doesn’t sound hollow if you knock it either.
