A contractor came today to assess the cellar. He quickly established that the primary leak is the ever-popular window corner crack, in my case running down the foundation behind the framing timbers of the wall between the furnace room and the rest of the cellar.

Boo, hiss.

So, first I must get in a carpenter to rip out the end of the partition and remove enough drywall to expose the entire crack. Then I can get a realistic estimate on repairing the crack, plus the carpenter again to make good the damage to the walls.

I hate finished basements.