expansion joints in walls

[Mike Wadsworth]

Hi everyone.  I have a potential retaining wall project in the works.  I live in the northeast, where freeze and thaw plays a role in every exterior concrete project.  I'm going back and forth between foam and cement block construction.  Either way, I plan on having a footing, with rebar for reinforcement.  Does anyone have any input on incorporating expansion joints into the wall.  Without them, I'm pretty certain there will be heaving and separation.  The wall will be 4' tall.  Thank for any advice you guys have.

[jeff kirt/ kirtbag Carving mix]

Hey mike, i don't believe you will need expansion joints in the wall. As long as your footing is below the frost line it should not move. Also, backfilling behind the wall with stone and having the proper drainage should prevent it from moving from behind also. Good luck buddy.

[Jeff Tobler]

If you build the wall with CMU (block) , use a couple courses of open bottom lintel blocks with #4 rebar. This allows you to have horizontal steel as well as vertical. Grouting the blocks in is a must. Backfill as Jeff Kirt recommended with stone. Backfilling with expansive soil leads to the heaving and separation  you are looking to avoid. Don't skimp on the footer either, a rule of thumb on retaining walls is footer width to be 50% of wall height.

[Mike Wadsworth]

Thanks guys.  Very helpful info.