Concrete blocks go far beyond the drab gray cinder blocks of the past.

Concrete Retaining Blocks

by Brian Barth

If you have an eroding slope on your property and you're wondering about the best choice of materials for building a retaining wall, manufactured concrete blocks are hard to beat for their ease of installation and good looks. In the past few decades, concrete block walls have been elevated to both a science and an art form. You will love the array of colors, textures and sizes that are available to choose from -- plus, they are designed to make beautiful curved walls with ease.


Concrete retaining wall blocks range from the size of a brick to pieces that require heavy machinery to lift into place. In choosing the size of block for your retaining wall, keep in mind the overall proportions of the structure -- the smallest walls look best when made with small blocks and the proportions of bigger walls generally dictate using a larger size of block. Also keep in mind the weight of the blocks if you're doing the project yourself. To give you a general idea of what they weigh, a 6-by-8-by-12-inch block weighs around 40 pounds, while a 6-by-18-by-12-inch block may weigh 80 or 90 pounds.

Colors and Textures

The great thing about concrete blocks is the tremendous range of color, texture and style that is available. Of course, the most most basic gray cinder blocks still can be used for retaining walls, but other blocks are made to accentuate the landscape and fit with your overall design theme. Earth tones are the most common color scheme, ranging from light tan to dark brown. Reddish brick colors are also quite popular, as are blocks with a mix of earthy and metallic tones swirled together. The basic blocks have the texture of any other concrete product, but there are others that are processed to closely resemble natural stone -- some with a rough finish reminiscent of stone from desert landscapes and others that have been tumbled to create rounded edges as if they were found in a river bed.

Special Features

Your retaining wall can be straight as an arrow if you'd like, but manufactured wall systems are designed to accommodate circles, arcs and undulating curves. The blocks for this purpose can be identified by their trapezoidal shape, as opposed to conventional rectangular blocks. The tapered sides of these blocks allow each one to be placed at a slight angle to the next to make smooth, sweeping curves. Most block wall systems also have a little concrete lip on the back of the bottom side of each block. This goes just behind the top edge of the block below, making each row lock into place and giving the wall a consistent taper into the slope. Wall caps give a finished look to the top of the wall and you can use them as a bench if your wall is an appropriate height for sitting.

Project Planning

Building a retaining wall is a major endeavor, so it's best to know what you're getting into in advance if you're planning to do the project yourself. First off, walls over 3 feet in height have special design and engineering requirements and will often require a building permit from your local municipality. Find a reputable contractor if you need a wall of this stature and make sure they are licensed and insured for the work required. Building a concrete block retaining wall means a lot more than just stacking the blocks -- they need their own foundation to rest on, a drainage system between the wall and the slope and a fair amount of knowledge and skill to make them come out level, safe and sound. The suppliers of concrete block retaining wall systems are an excellent source for more information on exactly how to build the wall you need.

About the Author

Brian Barth works in the fields of landscape architecture and urban planning and is co-founder of Urban Agriculture, Inc., an Atlanta-based design firm where he is head environmental consultant. He holds a Master's Degree in Environmental Planning and Design from the University of Georgia. His blog, Food for Thought, explores the themes of land use, urban agriculture, and environmental literacy.

Photo Credits

  • Hemera Technologies/ Images