Pond Boss Forums GENERAL QUESTIONS Property Projects & Construction Construction Question - Retaining Wall on Clay

That height walls you will need a good foundation with rebar coming up from that foundation a good way into the walls, and the horizontal rebar needs to tie to that vertical rebar.

Mom & Dad had 40"' vertical walls that tapered to 18" height, poured, 8" thick to hold back soil. The contractor didn't put rebar up from the 4" thick slab and didn't have a footer under the wall. It lasted for 6 years before it started tipping in at the top due to the soil pressure (clay). EVERYTHING had to be removed, a footing dug out, rebar put in and everything re-poured. This was on a 8' wide, 50' long "chute" that went from 6" height to 40" height at the walk-out basement doors. I can't remember if the 2nd contractor used #6 or #5 rebar for vertical pieces, but they weren't #4's.