A cold joint is a weak seam formed when pouring new concrete against concrete that has already started to set. Avoid cold joints by pouring continuously—plan ahead, have enough concrete and workers, and complete the pour without. A cold joint in concrete is an area or surface with a structural discontinuity caused by the delayed concrete pouring between two layers of concrete. What is the difference between a contraction joint, isolation joint, expansion joint, construction joint, and a cold joint? A. If this is not achieved, there is insufficient adhesion subsequently. Understanding what cold joints are, their effects, how to prevent them, and how to repair them is essential for ensuring the quality and integrity of concrete structures. In this comprehensive guide, we'll delve into all aspects of cold joints in concrete.