Sound insulation testing is not normally conducted on internal walls or floors within a property, though this does not mean that they are not required to have a level of sound insulation. Internal walls are required to perform at 40dB Rw in all home nations. Internal or intermediate floors are required to perform at 40dB Rw for England, Wales and Northern Ireland and 43dB Rw in Scotland. Testing for internal sound insulation levels is not done as part of pre-completion testing as it is not possible to test internal partitions as there is always a doorway into the room which noise will travel around or through rather than the floor or wall, giving a false result.