It was fascinating to see the progress with the station floor at Wingfield this week.
Following the careful break out of the modern concrete floors, the layers of the new floor are now being installed.
The substance with a coal like appearance is Geocell, which is actually a foam glass aggregate made from 99% recycled glass.
It is an insulation material for underground use and is both economical and environmentally sound.
It is surprisingly light weight and combines a drainage layer and insulation in a single product, thus reducing the depth required for floors etc.
The next layer will be a geo-textile membrane, followed by geogrid for the underfloor heating and a lime crete screed.