This small job in Haverford was one detail: copper flashing where a bank of windows sits on a slate roof.
Why copper here
When a wall with windows rises out of a lower roof, water running down the roof hits the bottom of the wall. Without flashing it goes straight into the framing under the windows. The fix is apron flashing: a piece of metal that runs up the wall behind the siding or trim and lies down over the roof.
On a slate roof the flashing should last as long as the slate, which can be a century. Aluminum and galvanized steel do not. Copper does, and it suits the gray of the slate and the stone of the house.
HaverfordNov 2024How it is installed
The November 6, 2024 photos show the copper apron running along the base of the windows and turned down over the slate. Copper is fastened with copper nails or cleats only, because steel or aluminum fasteners corrode where they touch copper in the wet. Corners are folded and soldered rather than caulked.
HaverfordNov 2024The copper is bright in these photos. Within a year it turns brown, and over many years it may go green. Either way it keeps working.
