The most common way of finding a leak is to wet the caravan roof and watch for the points the water is seeping through.
Static caravan roof vent leaking.
If your caravan roof only has minor leaks and you have been able to identify where they are it might be worth rethinking whether you need to replace the whole roof or resealing the roof would be an option.
Most caravan leaks occur at a join or attachment hole where a screw or rivet holds down the sheeting to the frame.
Unfortunately the rubber boot damage often becomes the main cause of roof vent leaking.
Some leaks can be hard to track to their source but one i recently found was a pretty straightforward job.
It was leaking through the join of the handles so i fix it using a foolproof method buy the mastic that i used h.
Check out the step by step for evidence.
Replacing the entire roof is never a small job.
I applied different colours of dye to small areas at a time eventually i narrowed down the leak source colour of dye emanating within the caravan.
Many years ago i had an untraceable leak in a static caravan eventually i applied water to the roof containing drain tracing dye.