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.