I am fortunate to have a son that has practiced the art of landscaping for a number of years, and is a bit of an expert on building retaining walls. Here are a few tips he passed on to his Dad:
TIP #1: Use 10-foot lengths of either 4x4 or 6x6 pressure treated lumber. From experience Egin has found that these are the optimal length for larger retaining walls.
TIP#2: Use 1/2 or 3/4-inch rebar to secure the bottom row. Drill the appropriate size hole and drive at least a 3-foot length of rebar ever 4 feet.
TIP#3: Secure each row to the one below it with a 8-inch spike. Drilling pilot holes just smaller than the spike will make this go much easier. Again drive these every 4 feet making sure to offset each row by 2 feet. There should be a spike on each row at the corners.
TIP#5: Try not to make any retaining wall higher that 7 or 8 rows high. It is better to have a series of retaining walls to retain a large depth than one big one. This will resist the weight of the grade by spreading the pressure over a greater distance.
Related Posts:
5 Tips for Building a Strong Retaining Wall
5 Tips to creating a Great Retaining Wall
;-)