A proper flashing on a brick chimney prevents damage to the interior of the home, and ensures the long term functionality of the chimney.
A brick chimney adds value and functionality to a home, but without the proper roof to chimney flashing, it can cause a lot of problems. At Valley Roofing & Exteriors, we recommend a 2-piece flashing that allows seasonal movement between the house and chimney to occur without causing any problems. The 2 pieces consist of a step flashing that is integrated with the shingles, and a counter flashing that covers the step flashing, and is fastened only to the chimney. This allows seasonal movement to occur without stressing the fasteners as can happen in a one piece system. We also prefer a straight counter flashing over a stepped counter flashing as it completely seals the flashing, and limits the number of pieces that are necessary to be installed.
Here is an example of a chimney flashing in Harrisonburg that had failed, and had caused the plywood around the chimney to fail.