I got hold of a kiln brick. I had been using them for a long time as a heat regulator. I had never seen anyone using it in the UK. For me then the idea of BBQ was not to take your kitchen outside and have an all singing and dancing peace of equipment. Tomorrow night will be the first time I will use a gas bbq on the balcony. We have the traditional Croatian wood fired oven and grill downstairs, its to hot in the summer to bother.I am going to have to try your brick trick.