Leak next door

[Gw1743]

Hi,

I finally got round to investigating the dark patch in my hallway and discovered my next door neighbors have a leaking pipe that comes out of their wall into the garden. I don’t know how long it’s been leaking for as their garden is so overgrown I can’t see the pipe from mine. I can only assume the constant running water is the cause. The right side of the wall is a new extension not even 4yrs old. Is it a simple case of once the pipe is fixed (management company sorting but very slow and not keen to take responsibility) then allow the wall to dry out then repaint or do I need to do something else? 
(In the photos the brick wall behind the pipe is my extension)
Thanks

[Mr Punter]

It will take a long time to dry.  Yes, just get rid of the loose stuff, wipe with bleach and off you go.

[Temp]

A desk fan blowing on the area will help speed up the drying process but don't let it fool you. It will dry the surface quickly making you think its done but there will still be quite a bit of water hiding in the wall.  I'd give it a few months before repainting.

 

Then you might consider painting it with Zinsser Primer Sealer (@ Screwfix) before applying a regular emulsion. I'm not sure which is better, the Zinsser BIN (Shellac based) or the Zinsser 123 (water based) but Zinsser paint is darn good where there is any damp. I'm using their paint over a shower that causes water drops to form on the ceiling.  

[Gw1743]

20 minutes ago, Mr Punter said:

It will take a long time to dry.  Yes, just get rid of the loose stuff, wipe with bleach and off you go.

Thank you. How long roughly do you reckon I should leave it to dry out?

[Mr Punter]

Sounds crazy but I would leave it a year.

[Gw1743]

11 minutes ago, Temp said:

A desk fan blowing on the area will help speed up the drying process but don't let it fool you. It will dry the surface quickly making you think its done but there will still be quite a bit of water hiding in the wall.  I'd give it a few months before repainting.

 

Then you might consider painting it with Zinsser Primer Sealer (@ Screwfix) before applying a regular emulsion. I'm not sure which is better, the Zinsser BIN (Shellac based) or the Zinsser 123 (water based) but Zinsser paint is darn good where there is any damp. I'm using their paint over a shower that causes water drops to form on the ceiling.  

Thanks, I’ll look into that paint.