At a recent home inspection on San Juan Island, I discovered rusting/corroding flashing details at the chimney that should be further evaluated and repaired to help prevent potential leaks to the interior. Also, the installation of chimney caps is advised over open flues to prevent water intrusion which can reduce the life expectancy of masonry fireplaces. Finally, treating and removing organic growth from masonry is advised, together with applying a masonry sealant to properly maintain your exterior masonry elements.