Retaining Wall Archives - A&A Materials Inc

Building a stone retaining wall is fit for DIYers if the wall is no higher than three feet. Utilizing the dry-stack method, concrete and mortar footings are not necessary.
Learn the simple, no-concrete way for building your stone retaining wall through stacking the stones on top of one another—the dry-stack technique.

What Is a Dry-Stack Retaining Wall?

A dry-stack retaining wall is constructed utilizing natural stones that are “stacked” on top of one another, with the whole retaining wall on top of a gravel foundation. Dry-stack retaining walls drain adequately. Correct drainage decreases damage and the requirement for retaining wall repairs.

Organize the Stones

Organize your retaining wall stones approximately by shape and size, making different piles as you need. Do this off the project site, not at the retaining wall’s location.
Use larger, flat stones for the foundation. Reserve smooth, undamaged stones for the capstones at the top of the wall.

Pare Down the Stones

Hammer off points and other unusual shapes using a maul and brick chisel, as required, to make them fit throughout construction.

Run a Line Level

Hammer wooden stakes down and run a masonry string between the stakes to mark the location of the front surface of the foundation of your retaining wall. Position a line level on the string, then pull the string tight from one end, and level the line prior to tying it to the stake.

Dig the Area

Dig out the area, beginning from the string and moving back towards the incline. Dig twelve inches into the ground for creating a flat, level channel for the gravel foundation. Dig into the incline for creating a six- to twelve-inch-wide space between the backside of the wall and the incline.

Add Landscape Fabric

Cover the dug-up area with bands of landscape fabric. Lay the fabric vertical to the front of the wall. Extend the fabric a couple feet onto the topmost-level ground. Overlap neighboring strips of fabric by six inches. Cut the bands to length using a utility knife.

Build the Wall Base

Fill the channel with five inches of compactible backfill. Rake the backfill so it is level and flat. Tamp the backfill with a hand tamp or they are available for rent. Add a one-inch layer of gritty sand over the backfill. Smooth the sand using a short two by four board so it is level and flat.

Lay the Initial Course

Lay larger, flat stones along the leading edge of the channel to build the initial course. Remove or add sand underneath each stone, as required, so the tops of the stones are flush with each other. Place the four-foot carpenter’s level across several stones for leveling the course.

Lay the Secondary Course

Lay the secondary course of stones on top of the first, once more spacing out the joints. Rigidly set each stone to decrease wobble.

Refill the Wall

Refill the space between the wall and the slope with drainage backfill. Rake the backfill level and flat, then tamp it thoroughly using the hand tamp. Refill only up to the uppermost course on the wall.

Install Tie-Back Stones

With higher courses of stones, position tie-back or dead-man stones. Tie-back stones extend back into the incline for attaching the wall to the earth. Place the stones every four feet horizontal feet (4 to 1 ratio)

Fold Back the Fabric

Fold the landscape fabric over the runoff gravel as you get close to the peak of the wall. You can do this prior to the last one or two conventional courses or ahead of the capstones (the highest course), subject to how much soil you want at the top of the wall (for developing greenery).

Place the Capstones on the Wall

Place the top course of stones—known as capstones—for completing the top of the wall. If you desire, you can glue the capstones to the course below for keeping them secure. Utilize masonry glue.

Backfill With Soil

Trim the landscape fabric so it is right below the top of the wall. Blanket the landscape fabric and backfill on the backside of the top of the wall with soil, according to need. For growing greenery in this area, the soils layer should be at a minimum of five to six inches in thickness.

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Gravity Wall or Geo-grid Reinforced Wall?

Several questions must be answered to build the appropriate type of retaining wall. For instance, is the soil clay, sand, or a mixture of the two? What lies above the wall: a driveway or something weightier such as a pool? Is the ground above or below the wall going to be even or inclined? What is going to be the height of the wall? All these aspects are going to determine if you will require a Gravity Retaining Wall or a Geo-grid Reinforced Retaining Wall.

Gravity retaining walls are ones that rely on their own mass and setback to hold back the material and are usually shorter in their height. Many retaining walls are perfect for this kind of wall, since they get stacked together, they lock together to create a setback. This setback assists the wall in supporting the pressures from the materials behind it.

Reinforced retaining walls are ones that utilize some kind of reinforcement to give more durability to the retaining wall itself, therefore improving its capacity to retain the materials behind it. Geogrid is placed between routes of blocks in the wall and rolled back into the incline or hillside throughout installation for creating a stronger and more balanced soil mass. Basically, the blocks, the geogrid and the reinforced material mass work together for making one large, heavy retaining wall framework. Oftentimes grid is not a functional solution on a project because of space or other site conditions, so optional reinforcement materials need to be utilized – like no-granular concrete, soil nails or ground anchors. These kinds of reinforcements usually require an outsourced engineer for design and a licensed contractor for the wall’s installation.

Types of Retaining Walls

In recent years a lot of different retaining walls textiles have helped renew the landscape in which we live. Typical retaining wall products can comprise of railway ties or treated timbers in addition to natural stones, wall stones, concrete blocks and bricks.

Whereas wood is often a low-cost and simple option for a retaining wall, its shorter longevity makes it a relatively substandard option. When the wood breaks down, your retaining wall and the strength of your available space do too. Rocks, stones, or boulders (or a combination of them) can create appealing retaining walls, however, the installation of these materials can be costly and laborious. Additionally, maintenance of stone walls can be challenging, because over time they could break down or become home to pests and invasive weeds.

Mortar or cast-in place retaining walls are another alternative. These walls can be installed with a multitude of flagstones, veneers, bricks, etc. which add consistency and style. Nevertheless, these structures are inflexible and don’t move and flex with environmental changes, monsoons and other natural forces, and can be very costly to build.

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How to Build a Retaining Wall