Resolving Water Leaks and damage may involve inspecting the lead/sub flashing, observing wood near the chimney for water stains, and maybe even mold damage due to consistent or steady water penetration.
Being successful when dealing with water could require a combination of repairs. the following are some or the ways that may be necessary to correct water penetration:
A. A chimney cap; installing a chimney cap with the proper lid can cover the surface area of the top of the chimney which can greatly prevent water absorption.
B. Grinding and re-pointing the chimney with new mortar can help immensely.
C. Spray on application of a water repellent containing the chemical Siloxane (the main ingredient in the top water sealing products today)
D. Repairing or replacing lead/step flashing in and around the chimney.