We just published our new AB Landscape Wall Guide and it got us to thinking, “How do you know what block is the best block for your site?” As you are planning your retaining wall project, it is easy to get overwhelmed with all the retaining wall block options. To help narrow this field of choices, the first thing I would recommend is to contact your local dealer to see what block is available in your part of the country.
If you are fortunate enough to have both the AB Collection and AB Europa Collection available in your area, it comes down to your personal preference whether you like the hand-laid look of the antiqued AB Europa Collection or the smooth, fluid finish of the AB Collection.
2 Course Pattern
Why?
Well, as you wall gets taller there is more soil behind the wall pushing against it. After about 3 ft (1 m) you start to get to a point where the weight of the block isn’t enough to hold back all the soil. At this point, the full size blocks may help keep the wall a gravity wall; otherwise you will need to add geogrid to the wall for stability.
Tom
I have a question or two about the pattern.
1. The brochure says a 2 course pattern should be used for turns. But, my wife really prefers the 3 course pattern. Besides that, the 16″ height of a 2-course pattern would be too small, and a 32″ pattern (2-course x 2) would be too tall. We think a 24″ 3-course pattern may even be a little tall for our project, but I think I can make it work…if we can turn the 3-course pattern. Can we?
2. How do you estimate the wall (using the spreadsheet) when a portion of the wall turns into the hillside? And along the same lines, how do you estimate for stepping up and stepping down?
Thanks.
Thank you for submitting your questions to the Allan Block Blog. For your patterned wall I would recommend a 2-course pattern for ease of construction, but there are times when a 3-course pattern may be used. If the curve has too small of a radius, you will end up modifying the bottom notch of the blocks to allow the wall to flow around your curve. For details showing how to modify the notch, see the Tighter Curves section of the AB Landscape Wall Guide.
Other things to keep in mind:
• Even with a patterned wall, we recommend using full size blocks (AB Classic or AB Dover) for the base course of block. Burying a little more block would allow you to build the wall to the exact height you are looking for.
• The patterns found in our Pattern Brochure are for guidance only. Feel free to modify the pattern as necessary to randomize your wall.
• An alternative to building a 3-course pattern would be to build a 1-course pattern and a 2-course pattern.
Using the AB Landscape Wall Estimating Tool is a great way to estimate the materials you will need on your job. To get a more accurate material estimate when your wall is changing height, you will need to use a different “Wall” in the tool for each different height. For example, if your wall was 100 feet long and stepped down from 7 blocks tall to 4 blocks tall, I would enter the following information:
• Wall 1: Number of Courses = 7, Wall Length = 25 ft
• Wall 2: Number of Courses = 6, Wall Length = 25 ft
• Wall 3: Number of Courses = 4, Wall Length = 25 ft
• Wall 4: Number of Courses = 4, Wall Length = 25 ft