Isolation joints permit horizontal and vertical movements between abutting faces of the slab and fixed parts of a structure.
 
 
 
 
 
 
 

Contraction joints provide for horizontal movement in the plane of a slab or wall and induce controlled cracking caused by drying shrinkage.
 
 
 
 
 
 
 

Horizontal construction joints in walls with V-shaped (left) and beveled (right) rustication strips.
 
 
 
 

Typical contraction joints
 
 
 
 
 
 
 

Construction joints are stopping places in the process of construction. Construction-joint types a, b, and c are also used as contraction joints.