My Dad has a flat roof over his garage. It's covered with tar and felt.
We had an unusually hard and cold winter last year (Republic of Ireland) and since then the roof has developed a leak.
We've made several attempts to patch it, with no success. We know where the water is exiting the roof but we can't tell where it's getting in.
Is there some device that will trace the water from the leaks exit back to where it's getting in under the felt?
I'm thinking more tricorder, and less dowsing rod 🙂