#Retaining wall blocks install

Safety gloves and goggles are recommended, along with a dust mask while cutting, and a back brace can help with lifting heavy blocks. Key tools include a flat blade shovel, a hand tamper or vibrating plate compactor for compacting soil, stonecutting tools such as a diamond blade circular saw or a hammer and chisel, and a bubble or laser level and a set of stakes with string to ensure each course is level. Additional gravel should be used for backfilling in place of native soil to keep it from collapsing and to improve drainage, and landscaping fabric laid between the backfilling and recompacted topsoil further aids in draining groundwater by keeping the soil from slipping into the gravel. A compacted base material, either sand or gravel, is vital for the foundation.

This is done either with lips and grooves in each block or with slots through which pins are inserted to anchor blocks to each other.Īlong with the blocks, you'll need some other materials to help bring it all together. Additionally, retaining wall blocks usually interlock to improve stability. If you choose natural stone, you best bet is to use quarried stone that has been cut at the quarry to be more easily stacked 'rubble' or 'boulder' walls using irregular stacked stones are tricky to assemble in a stable structure. Concrete wall blocks are common and reliable, not to mention they usually come ideally shaped for building retaining walls, but natural stone is a good choice for those who find concrete to look too artificial. A retaining block can come in a variety of shapes and compositions. The most apparent material you'll need for your retaining wall is the blocks that make up the wall itself.

#Retaining wall blocks install

To aid in draining groundwater, be sure to install a drain pipe at the base and use gravel as backfilling behind the wall, since it drains more effectively. Proper drainage is also vital, as groundwater getting trapped behind the wall adds extra weight against it. Also, two features are used to counteract the concentration of pressure at the base: the first course is buried partially by compacted soil to keep it from being pushed out and the blocks are stepped back so that the wall as a whole leans against the retained soil. To make the wall as stable as possible, retaining wall blocks should have a well-compacted base for the lowest course (row of blocks) to rest on and be laid out with each course staggered from the one below. As a rule of thumb, separate these tiers with distance twice that of the walls' height. If you need to retain a greater slope, you can use multiple tiers of walls-not only does this create a distinctive terrace-like appearance, each individual wall has less pressure against it. Large scale retaining walls-over 4 feet tall-need additional supports, and most municipalities require a building permit and input from a certified engineer before you can start constructing such a wall, so they're generally outside the scope of a DIY project. Garden walls and short retaining walls made from stacked stone or concrete wall blocks can stand on their own when built correctly, using their own weight as well as friction between the wall and base and an interlocking block system to push back against soil.

Driven by gravity, this wedge pushes against the retaining wall, with the pressure concentrated at the base. Your wall won't be holding up an entire hillside, just the wedge of soil between itself and what is called the 'failure plane'-the steepest slope that existing soil can naturally form before it collapses under its own weight. There's much to consider in designing and constructing a retaining wall, though, from aesthetics and material choice to managing water runoff and the weight of the retained soil.įundamentally, retaining walls are built to hold back soil, and the weight of that soil puts tremendous pressure on the wall. With retaining wall blocks, it's also easy to make a DIY project of it-perfect for homeowners that want to take their landscape into their own hands. Whether it's for aesthetic purposes or to make sloped land usable for garden beds and outdoor spaces, a retaining wall is a valuable landscaping tool when used properly. Retaining walls serve a different purpose than outdoor freestanding walls-they're not built to fence in an area or to mark property but to aid in landscaping, holding back soil to fight erosion and let you reshape slopes.