Hi Mr Bright, thank you for your work and always sharing with us. I hope you had a nice stay in Gh recently. Please let me contribute here: POP is equally done on a concrete ceiling. It will not fall if done well with enough binding wires. They proceed with a tight grid 20x20 and notch the ceiling to install the binding wires and the plaster and fiber mixture. Togo artisans have always been trained in that technic since most of their roofs are concrete ceilings. It never falls. Actually, POP is stronger on concrete than when it is done on roof trusses because some carpenters may choose a poor quality wood that can bend or break under the weight of the POP and/or Plasterboard. Concrete slabs are much stronger to withhold their weight.