Can a dripping overflow pipe damage foundations

Question

Our neighbours have a dripping overflow pipe that is right up against the side of our property. I have mentioned it to them but they don't seem concerned and are not in a hurry to get it fixed. I understand that a leaking pipe can undermine foundations is the same true of a dripping overflow pipe leading to water continuously sitting against the walls. On the one hand; external walls are supposed to be exposed to water, but on the other, its continuous water

It's dripping such that a 6 litre watering can placed underneath (neighbours solution) fills up over night.

Obviously the issue causing the overflow to leak should be fixed but I'm trying to gauge if that's entirely my neighbours problem or if it could cause damage to my house and I should be more insistent.

If relevant we are in the UK, a somewhat cold, rainy country¹ that rarely has built in AC units

¹That makes the UK sound horrible, it's a nice place really

Answer 1

That looks like a drain for the condensate from their air handler for their AC unit. If so, it's not something they can fix, it was installed that way. It also looks like there's a white PVC pipe exiting that wall too that might be from your AC unit.

It could also be from a leaking pressure relief valve from a water heater. Is the water warm or hot? The piping used to be done this way. If so, the neighbor should get this fixed, wasting water and energy.

You might try diverting the water with one of these water diverters, see picture below from Amazon.

Answer 2

The answer is simple yet the solution can be tricky. There should never be water constantly dripping from any source along the foundation of a structure. A simple solution is to shut off the drip. However it may be from an AC drain or some other necessary drain and cannot be shut off. Then there should be pipe added to carry the water away from the foundation. Now comes the tricky part. The pic showed your home and the neighbors home sharing a common wall. Depending on the laws in the area where you live you may , or may not be allowed to address this yourself.
If there is a manager of the complex ask them. Perhaps there is a board or some entity responsible for the common area. Tell them about this problem and be sure to include that it is more than an annoyance, but a concern with the long term safety of the structure. Since you discovered this instance there may be other areas around the building/s that have the same issue with the other owners ignorant to the long term implications. They all should be addressed. Good Luck