Hey folks, I hope everyone is good!! I just spent a little while reading through some of the Pisa and Siena Stone wall posts and learned a fair bit. The one thing I am still stuck on is probably the most basic so I thought I'd ask it here. My supplier gave me prices for the following "pieces": Standard 500 Unit, 333 Unit, 500 Unit and 925 Unit. What I am not clear on is which I use for the base and which I use for successive courses. Or, is only one unit used for base and courses and the size depends on how large the wall is to be? The wall I am quoting on is going to be approx. 150ft long and approx. 6-8" high. My assumption is I will have two courses below grade and two or three above grade. In looking at some of the info on the RisiStone site (see link below) it looks like the standard unit can be used for base course and the courses above. http://www.risistone.com/products/machine-placed-walls/sienastone So I think what I need to do is divide the width of the standard unit into my overall length of 150 feet, multiply by the number of courses and then multiply that by the cost of each standard unit. 150 feet divided by 48 in. (width of standard unit) = 37.5 units per course 4 courses x 37.5 units per course = 150 units Coping would also be 37.5 units Then I need to account for: - excavating trench - installing and compacting base - adding drainage tile (with sock) in behind wall - installing geotextile (will I need it for only 4 courses)? - backfilling with gravel - actual placement of blocks using clamp - finish work: adding soil and sod Am I on the right track? I am hoping Paul and SLC and some of the other "gurus" that I saw posting in the other threads will weigh in on it. Some dated back to 2002 so hopefully they're still around. THANKS ALL!