10/09/2026
**SMALL JOINTS. BIG IMPACT.**
🌡️ As temperature and moisture change, masonry expands and contracts. Without room for that movement, stress builds and walls can crack.
🧱 In clay brick, expansion joints allow adjoining wall sections to expand.
▪ In concrete block (CMU), control joints create planned separations that help control where shrinkage cracks develop.
🔧 For these joints to work, mortar must not bridge the gap. Backer rod controls sealant depth, while flexible sealant helps keep water out as the joint opens and closes.
Correct placement, width, and installation turn a simple gap into a functional construction detail.
🏗️ **The best lessons come from the jobsite: we’ve seen our properly installed joints make a difference, and through our restoration work, we’ve corrected details overlooked in completed projects.**
Barnes Construction Company
Built on Precision, Driven by Performance.