One of the biggest things you can do when caulking masonry if to use the right caulk. Polyurethane caulks generally work the best and are currently going to cost you (if you are going to do it yourself) about $5 a tube. Make sure you follow the manufacturer specifications. Also know that even the best caulk will break down by the UV rays of the sun within 7-10 years.
General advice. Contact licensed chimney expert for your particular situation.
For years, people throughout the greater Milwaukee and Waukesha areas have been turning to Smoke Stacks, Inc. for their chimney repair and relining needs. At Smoke Stacks, Inc. we believe that attention to detail, professional work, courteous service and honest prices are the qualities that make the difference.