Window Flashing around Rosette Corner Blocks
I am repainting a wall sided in red cedar clapboard, with 3/4″ x 3.5″ trim surrounding Anderson windows.
At the top corners (either side of the head casing) the builder installed rosette corner blocks, 1 18″ thick X 3.75″ square.
I want some ideas for how to flash around these corner blocks and head casing.
Some rot had developed around and under the blocks, which were nailed into 1/4″ plywood. The plywood was installed in a 4″ band around the windows. The plywood went over foam board insulation to create a nailing surface for the window trim. The foam is on top of very old logs (pre Civil War). There is no housewrap or felt. I guess they counted on the foam board to be a WRB, and did not bother with felt over the plywood.
They put aluminum drip edge over the casing, between the rosette blocks. But, there is no flashing over the blocks at the corners. They depended on caulk alone, with predictable results.
I could get a longer length of drip edge to extend the full length of the trim above the window, extending it out over the blocks. But I’m afraid it will look clunky, since the blocks are thicker than the casing. Maybe fashion a wooden drip cap over the casing?
Does anyone have a good detail picture of how to trim and flash in this situation? Thanks in advance.
Replies
You could easily bend aluminum flashing to make a suitable drip cap. Make it a hair longer than the block is wide so it can overlap the window drip cap. Or you could use rubber membrane.
Also, the blocks should have been made with a bevel on top, to drain better. This is something that craftsmen 100 years ago would have done without even thinking about it.