Wet above skirting board - advice please?

[Ppdavies9494]

Hello!

Nit sure if this is the right place to post but hoping someone can help!

There is a wet circle is shape above some skirting in my house but I'm not sure what is causing it! Does anyone have any ideas? It's nowhere else in the house!

 

[HERTS P&D]

What is on the other side of the wall?

Andy

 

[Ppdavies9494]

My neighbours garden, there's no tap by there it's the side of an extension (can see the corner in the picture). Thanks for replying!

 

[HERTS P&D]

Any faulty guttering? Try and post a picture from your neighbours side.

Andy

 

[bobasd]

is ther a DPM membrane under any solid floor?
is that dotandab plasterboard?
is it a solid wall or cavity wall?
is that outside corner, or the return wall where the breakthru for the extn cam?
an solid floor below the large tiles?
is the ouside rendered?
is the outside ground level lower than the inside FFL?