Size the trench so there's enough room for the retaining wall block and at least 8 in. of space behind it. Excavate deep enough to completely bury at least one full course, including space for 6 to 8 ...

Q. Can you tell me how to build a retaining wall? Are retaining wall blocks a good choice? What critical things do I need to know so that I don't have a collapse or other failure in the years to come?

Los Angeles officials on Friday banned tall retaining walls that dot the city’s canyon communities from Woodland Hills to Mount Washington, with critics calling the massive bulkheads “the hillside ...