What's causing this water line on my hallway wall??

Working_Mum

What is the indentation on the side wall? It looks like it is in the same space as your horizontal condensation mark? I would be getting my stepladders and taking  a closer look in that area - small cracks may see the water getting in.
I work for a surveyors and we once had a case where there was a weird patch of damp/stain on an internal wall of an old property - eventually we discovered an old window frame which had been badly covered over was the cause!
Good luck!

Homer_home

frayedknot said:

Homer_home said:

That would be a totally random place to run a water pipe , as that is clearly an outside wall I would be looking at your pointing

Any chance of some pics of the outside wall from the outside?

Not really random , the pipes have to run somewhere and it's flats so anything usually goes.  What are you hoping to see outside? The pipe runs along the inside of the wall, it will be a cold rising main so quite cold particularly in winter and may cause condensation. With it being flats i.e bodge central , i bet the pipe is about 2mm under the plaster.

That would be the most random place to put a water pipe ever , for starters your asking for trouble cause somebody could easily put a nail through it and there's loads of other reasons there's not a water pipe there but I can't be arsed listing them all

And as for what I'm hoping to see on the outside of an external wall where there just happens to be a leak................... The cause of the leak perhaps? Hhhhmmmmmm

Homer_home

I'm going to assume your kitchen is the room in the corner with the dual aspect windows? If so I would be looking very carefully for a leak from that waste pipe under the sink which is travelling into the hole in the wall and along your hallway wall 

Your pics appear to show the leak coming from the right hand side as there is a slope running from right to left , which says the leak is running from right to left because as you know water will generally not travel uphill cause of that wonderful thing called gravity