Just thought of a way.
If you have a region of roof where you need to know exactly where the leak is coming from you can divide the roof say into 8 parts and hose each one in a different colour water.
8 packets of dye (tile grout die perhaps), using the darkest colour at the lowest of the eight regions, and working progressively upwards to the lightest colour and topmost region.
Would need bucket hose pump.
Then you can tell where the leak is from the colour of the interior stain and repair the right bit.
Another way is to get a bendy camera and stick it through a light socket.
If you have a region of roof where you need to know exactly where the leak is coming from you can divide the roof say into 8 parts and hose each one in a different colour water.
8 packets of dye (tile grout die perhaps), using the darkest colour at the lowest of the eight regions, and working progressively upwards to the lightest colour and topmost region.
Would need bucket hose pump.
Then you can tell where the leak is from the colour of the interior stain and repair the right bit.
Another way is to get a bendy camera and stick it through a light socket.