In my newly purchased house, there is a built-in but disconnected expansion tank. The tank is located in a room upstairs, and I want to remove it. When I tore down the "walls" that were built around it, there is some kind of insulation and sawdust. However, they have not laid any floor, and the tank is propped up with wooden blocks. Does anyone have tips on how I can create a floor that can be stood and walked on? The hole around the tank is about 50 cm * 50 cm.
