Attached are three free graphics showing a tall retaining wall built as an extension of the basement wall versus a properly designed cantilevered retaining wall. Basement walls are “Propped” retaining walls held in place by the subfloor system at the top. By extending the basement wall geometry and reinforcement to build a retaining wall over 4-foot in height violates modern building codes. This results in the majority of retaining wall failures I see. The lack of lateral restraint at the top is the root cause of the failure. The second issue I commonly see is the retaining wall is not properly attached to the basement wall. Retaining walls that were built after the basement was poured often are not attached to the basement wall or poorly attached by drilling in a few inches and sticking a rebar in the hole. The preferred method is to install the dowel bars in the basement wall forms and allow the dowels to stick out through a hole in the forms. Drilling the dowels into the basement wall later and anchoring them with epoxy takes time, skill and knowledge of the proper depth and knowing which epoxy to use.
4 Likes
Super nice graphics!
If you are looking for projects; How about wood timber, CMU block or poured concrete retaining walls over 4 feet? I am constantly writing these up for issues resulting in poor design/install.
I have these I stole from somewhere if they help you a bit. Not as pretty as Randy’s but they ain’t bad.
6 Likes