Contraction Joints for walls Contraction Joints for walls Deliman (Civil/Environmental) (OP) 20 Mar 09 14:41 On a Concrete retaining wall, the contraction joints should it be filled with expansion joint material or left open? Could we use brick mortor instead of the expansion joint material? RE: Contraction Joints for walls JDCengr (Structural) 8 Jul 09 18:14 Your post is titled "Contraction Joints" but your question says "Expansion Joint." A contraction joint is just a planned crack location. An EJ has a gap.It's important to keep rocks and other material out of an expansion joint. Otherwise, if something gets in the joint in the contracted state, it may keep the joint from easily moving as the concrete expands,causing unplanned stresses. Joint material is a good way to keep that from happening, though there are others. RE: Contraction Joints for walls jike (Structural) 14 Jul 09 13:27 Contraction joints in retaining walls would not have expansion joint material nor any other material. It is just a weakend plane thru the wall where cracking can occur (in a relative straight line) as the wall shrinks. The joint may be caulked (for appearance) if desired, but make sure the caulk that is selected can accomodate the anticipated movement without tearing.