Similar to concrete, masonry structures are easily repaired using the same techniques and products as used on concrete structures. Special care must be taken to replicate the existing appearance of the masonry unit. Continuous crack repair is replaced with strategic placing of ports to inject epoxy at every point at which bonding is capable. Epoxy surface sealers are often removed or replaced altogether with mortar in order to disguise any appearance of repairs. These chimneys in California were cracked and badly in need of repair.