Hello, We have a old chimeny built in 1980s. The exterior base seems to be retaining water throughout the year. Freezing in the winter and cracking in warmer weather. I have attached pictures. We are wondering if it would be cheaper and easier to just demolish it all and just repair the walls? Or to repair the foundation which is crumbling away. The structure seems to be mainly cinder blocks. It is slowly crumbling away and we are worried it may all come down. We aren't sure how structurally sound this chimeny was built so we would appreciate any advice. Thank you in advance.