Damp under bay windows

[MrsSilenceDogood]

There is damp on the interior wall where the bottom of the bay meets the top of the wall. The damp only appears to be at the corners. The window photographed is on the first floor, but I also have the same problem with window on the ground floor. How can I fix this? Can I fix it from the inside? As I am a beginner, a quite detailed explanation would be amazing.

 

[blup]

It could be ingress of moisture from outside, the rain has got into the render/brickwork and not dried out. Its also possible that the room itself isn't kept war and damp has developed, although this would usually manifest itself as black mould. Inspect externally under the windows to see if there are signs of damp or gaps that would let moisture in. The remedy may be to chop out the plaster and let the wall dry out, replacing with breathable plaster.

 

[JohnD]

Rainwater penetration, the defect will be on the outside. Photograph the ground floor window all round. It will be easier to reach, Most likely the fault will be same on the other. Look at all joints for gaps. Water may be entering at the top and running down.

Sometimes bay windows have bad or missing gutters and water spills over.

 

[MrsSilenceDogood]

Hi John, thanks for the help. See below photos.

+8

Bay Window

• MrsSilenceDogood
• Today at 12:35 PM
• 17

 

[JohnD]

Good windows, set into the wall in the post-1666 London style. I think not likely the source. But I see a glimpse of a downpipe beside the bay. Is this near the damp?

And a manhole cover in front of the bay.

Please post a pic that includes the roof and gutters above the bay, and any external signs of damp near the downpipe or any other plumbing or overflows. How often do you water the plant trough? Does it have a saucer or tray to catch any overflow?

Just to check, the damp is both in the ground floor and on the first floor?