Modern concrete block walls are fairly sophisticated systems designed for strength as well as for fast, easy assembly. You simply stack the blocks on top of one another and secure them with pins, clips or interlocking edges. They’re designed to be set on a compacted gravel base. This allows them to flex slightly with ground movement and still remain strong. They’re available in a wide variety of styles in two basic sizes.
The garden wall size is the most common. These are relatively small (about 12 in. long x 4 in. high) and work best for accent walls around the yard and garden up to about 30 in. high. They’re perfect for terracing or building a raised planter. They’re lightweight (less than 25 lbs.), quick to install and widely available at home centers, nurseries and landscape supply outlets. You can usually build a wall with this size block in a weekend.
For heavy-duty walls up to 30 ft. tall, go with full-size blocks. They’re 16 to 18 in. long x 6 to 8 in. high and weigh 50 to 75 lbs. You’ll typically find them at landscape supply yards. Working with these blocks is a big job best left to pros. Big walls usually entail excavating and moving tons of soil and gravel as well as the heavy block itself. Walls over 4 ft. tall must be designed by a licensed engineer to ensure adequate strength.
If you think concrete block walls look cold and commercial, look again. You now have a wide variety of shapes, textures and colors to choose from. Select one that blends well with your yard, gardens and the exterior of your home. If possible, look at a completed wall to get the best idea of the appearance. Almost every manufacturer produces these four main styles.