I’ve used several water leak detectors over the past 20 years. The first was using the simple FSK devices from UK company Ciseco and their simple ‘personalities’. This was a two pronged contact switch on the end of a lead with the main box housed higher up
More details are here and this was mounted on the side of my shed at the bottom of our sloping garden where the river floods into our property. When triggered by rising water it sent messages via NodeRED to my mobile phone. One time I got a warning text when away from home and was able to talk with my family to ensure nothing was damaged in the flood water.
I cannot stress just how simple it was, and just how easily – even for a technical hacker like me – that the whole system “just worked”. I feel that is fundamental in our gadget obsessed age. They also ran for over a year on a single coin cell battery.
I currently need something like that working at my commercial building where I am a caretaker but for there (and for home) I’d like something that detected water along a horizontal access. An example is my newly refurbished bathroom that I’ve extensively waterproofed (or ‘tanked’ as they say locally) to keep the kitchen below dry. In spite of all the taping and sealant that I have put some water does splash over from the shower-over-bath arrangement and drop onto the kitchen ceiling. My solution is to buy some water-leak detection rope from AliExpress and couple this with a Dragino LWL01, having removed the existing twin-pronged detector and running the water leak cord across the exit for the bathroom where the water now trickles through. Similar detectors are around 5 – 8 times more expensive.
Once working, I’ll connect this via NodeRED (perhaps using the excellent CakeRED from Datacake) and link this back to my intelligent bathroom mirror to generate a synthetic voice via the espeak module saying “Water leak! Water leak!”
Perhaps then I’ll sleep easier knowing that the bathroom floor mat will be used correctly and my kitchen ceiling will be safe.