- Q.What is the best way to
flash around a wood-frame-and-stucco chimney for asphalt
shingle roofs?
A.The best way is to build and sheathe the chimney,
then flash to the sheathing with the same step flashing
that’s recommended for a brick chimney. Next, install
waterproof building paper over the sheathing and flashing as a
counter-flashing (see illustration at right). Attach the metal
lath or welded wire lath with furring nails, which keep the
metal spaced away from the waterproof building paper.
Apply the three coats of stucco, and finish the bottom with
a stop screed, or weep screed, about
1/2 inch above the shingles. The step flashing should show
enough to allow the application of a second layer of asphalt
shingles in the future without touching the screed.