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 ...

Highlights The typical cost range to build a railroad tie retaining wall falls between $2,000 and $2,400, while the national average cost is $2,200. The main factors that affect the total cost of this ...