GRC Bauhaus Promenade Flagstones 450mm x 450mm x 38mm - Cornish Slate Properties Compostion: Glass reinforced concrete. Dimensions: 450mm x 450mm x 38mm. Coverage: Approximately - 5 flagstones per m2. Weight: 17kg. Thermal resistance: 0.43. Description The Bauhaus acknowledges the simplification of form as characterised by modernist design. Both contemporary and stylish with an emphasis on the visual aesthetic. Eurodec GRC Promenade Flagstones are a specifically designed paving system to be loose laid onto paving support pads to provide an attractive, hardwearing surface to protect most flat roof waterproofing substrates from pedestrian traffic.