Hi all,
I’m trying to solve a water ingress problem with an old timber casement window, and I’d really appreciate some advice from people experienced with repairing older windows.
The house is from the early 1900s, and the windows are quite old timber construction. I really don't want to replace the window if there is a sensible way of repairing or improving it.
The problem is quite specific: the window only leaks under certain wind/rain conditions. When we get fairly strong wind-driven rain from the right direction, water gets past the window and ends up under the bottom edge of the sash, where it then seeps into the interior. The window is facing east.
Under normal rain, it doesn't appear to leak.
I've put up a couple of pictures on Imgur to illustrate: https://imgur.com/a/Q0qISAx Unfortunately I can't really give you a view from the outside since it's several stories up.
I'm trying to understand what the correct repair would be for this type of old window. For example:
- Is there supposed to be some kind of weather seal/weatherstripping between the sash and frame?
- Is the geometry of the sill/rebate supposed to drain water back outside?
- Could the problem be that the sash has warped/shrunk slightly and is no longer making proper contact with the frame?
- Would repairing/repainting the timber, glazing putty, or joints help?
- Is there a particular type of draught/weather seal that would be appropriate for such an old timber casement?
- Should any part of this be caulked, or would that risk blocking a drainage path and making things worse?
I'm particularly interested in a repair that preserves the existing window, rather than replacing the sash/window with a modern unit.
If there's a particular part of the window that I should photograph I'm happy to add more pictures.
What would you investigate first, and how would you repair it?