Damp issue

[Grant785]

Can anyone advise what might be causing this damp. The property is a 2 storey end terrace, walls are standard red brick with block internal. The damp is on the end wall at the top of the stairs just below a window. To my knowledge it has only appeared today after the persistent rainfall. Unfortunately, I only just noticed it so couldn’t really see the external wall properly in the dark, however it didn’t appear to have any damage.

 

[Si_]

Check the sealant round the window first. An easy fix if that's the problem. When I had similar in the old house a 2mm gap in the sealant let in three bucketfuls of water during a single rainstorm.

 

[Grant785]

Thanks for the feedback, will have to check in the daylight. I also had someone suggest the pointing could be causing it. Hopefully nothing major though.

 

[JohnD]

Is the wall plastered block, or plasterboard on dot and dab?

The round shape suggests water is coming through at one specific point.

 

[Grant785]

I believe it is plastered block

 

[Grant785]

I’ve been up on the ladder to see if there was any damage to the pointing or bricks but there didn’t seem to be anything obvious. The bottom circled area is where the damp patch appears internally. The only area of pointing that looked suspect is circled at the top of the picture, although I’m not sure if it’s anything or not. Unfortunately, I couldn’t get up high enough to see if there was any damage to the window seals, from where I was they didn’t look too bad.

 

[Grant785]

I’ve now just discovered a damp patch in the bottom corner of the window, the opposite corner to the damp on the wall. The plaster is very soft and the sill is swollen in the same area.