OK the obvious solution is replacement, but a temporary solution is required.
My daughter's house has a damp wall immediately under the upstairs bathroom window. The silicone round the window has been renewed, but the damp has continued. I took a look yesterday and spotted that the frame under the opening section of the window has cracked at the bottom hinge point. The crack neatly lines up with the seal on the window so water is being wicked into the crack.
The whole window will need replacing but a temporary repair is required in the meantime to stop further water ingress which is now affecting the kitchen downstairs. Any suggestions bearing in mind that anything with any thickness with stop the openable window shutting.
Thanks Rob