Today, for our Entertainment Room, we calculated the number of concrete blocks and concrete floor beams needed to build a sound reducing barrier around the walls and ceiling. There are twelve rows of standard dense concrete blocks, a lintel for going over the doorway and eleven 4 metre long concrete beams, the smallest one available (the 150mm by 120mm wide version) because it is just a false ceiling and not holding up any loads apart from itself. The concrete shell is approximately 5metres long by 4metres wide and 2.6metres high, just shy of the first floor joists.
The total number of blocks is around 635 but we ordered 650 to have some spares. We also ordered a ton bag of soft sand and eight bags of regular cement and a concrete lintel measuring 1200mm long, 100mm wide and 65mm thick to go over the doorway, it is rated at seven kilo-newtons (7kN/m) and we calculated that the block and beam ceiling will be 3.6kN per metre , loading over the 900mm wide doorway. That means a double safety factor, without us having to do anything special, just the minimum strength of the lintel we selected.
We have asked Jewson’s for a price on the whole job and we are waiting for it…