Here’s another example of someone doing wrong without realising.
You CANNOT have any type of screwed connection in a place that is not accessible. We had to attack this one from the ceiling as it was not possible to lift the floor above.
They have done a very neat job – granted, but screwed connections become loose and cause fires, the ones labelled – “electrical faults”
We repaired this with maintenance free connections as per electrical regulations that DIY’ers and some of out competitors don’t seem to bother with.