Retaining Wall Installation in 10 Steps

Concrete is one of the more inexpensive materials

A retaining wall built of stone

Glen Stromquist / Getty Images

Project Overview
  • Total Time: 20 hrs - 1 day, 6 hrs
  • Yield: 3 ft. by 10 ft. wall
  • Skill Level: Advanced
  • Estimated Cost: $1,500

Retaining walls make slopes more usable by flattening the slope and hindering water and soil from flowing downward. They can direct the flow of water in a direction you want it to go and prevent runoff from wearing down or eroding the landscape. They also serve an aesthetic purpose by making an area look neat and clearly defined.

What Is a Retaining Wall?

A "retaining wall" holds back (or "retains") the soil behind it and is often used for erosion control, terracing, and designing outdoor spaces.

The pressure behind a retaining wall, holding back tons of soil and water, can be enormous. Even a well-constructed wall can fail if a proper outlet for runoff is overlooked; the water pressure can make the wall fall apart.

Walls made of concrete retaining wall blocks less than 3 feet tall can be built by do-it-yourselfers, but anything taller requires a professional. Considerable knowledge and experience are needed before undertaking such a project. Research local building codes, especially if erosion and runoff are concerns.

The instructions and materials in this guide are for a retaining wall made of specialized concrete blocks made intentionally for retaining wall projects. It takes roughly 20 to 30 hours, depending on your skill level, if you have assistance, the weather, the materials used, and the wall length.

Before You Begin

Before installation, you must decide whether to build the structure or hire someone else. If you have limited DIY experience, do not attempt to build a retaining wall beyond 3 feet tall—anything taller requires a professional. Also, significant runoff issues will require professional assistance. If water runoff is a problem in your area, particularly your land, install a perforated drain pipe behind your retaining wall before backfilling.

Review local building codes, determine your soil type (organic or dense soils create too much pressure), and understand your climate (gravity and frost are the most significant factors) and runoff pattern.

Do not overlook the aesthetic component of retaining walls. Select a material that is in sync with your overall design goals. The material you choose will depend on factors such as your design tastes, the function(s) of the wall, and cost. Retaining walls made of materials other than concrete retaining wall blocks requires the assistance of a professional.

  • Concrete blocks: Some concrete blocks are made to build sturdy retaining walls. These interlocking blocks have a flange on the back side designed to slip neatly over the course below, allowing the structure to slope backward slightly as you lay course after course.
  • Stone: If going for a more natural look in your landscape design, choose a beautiful, raw material like natural hardscaping features, such as stone. Techniques for building a stone retaining wall differ from those for making a regular stone wall. This option is pricier than concrete blocks.
  • Pressure-treated timber or wood: Pressure-treated timber and lumber are prevalent in rural settings. Using wood is another costly alternative.
  • Poured concrete: Poured concrete (reinforced with rebar) is commonly used in commercial settings.

Retaining Wall Cost

The costs to build a retaining wall in the United States can cost between $3,000 to $9,000, with an average cost of about $6,000, according to Angi. The price is determined by height, length, style, and finish.

For the cheapest retaining wall material, you can build a 2-foot-tall vinyl retaining wall that costs about $10 per linear foot. In contrast, a 2-foot-tall steel or stone retaining wall can cost about $200 per linear foot. 

Concrete blocks are an excellent middle-of-the-road material, averaging about $80 per linear foot for a two-foot wall ($120 for a 3-foot wall). So, a 10-foot-long wall that is 3 feet tall will cost roughly $1,200.

Safety Considerations

Always call the "Call Before You Dig" number before building a retaining wall, so you don't damage buried utility lines.

Shoveling dirt and gravel can be hard on the back. Even if you haven't had problems in the past, you do not want this project to expose an underlying back issue. Invest in a good quality back brace.

Wear safety gloves when handling rock, concrete, or shoveling to protect your hand from cuts and abrasions. When working with stone dust and crushed stone, wear a facemask to prevent the fine particulate matter from entering your breathing passages. Goggles are imperative when shoveling crushed stone that can inadvertently kick up and ricochet toward your face as you're stooping down to shovel.

What You'll Need

Equipment / Tools

  • Back brace
  • Safety glasses
  • Safety gloves
  • Facemask
  • Shovel
  • Screed
  • Carpenter's level
  • Hammer
  • Chisel
  • Circular saw with a diamond blade


  • Concrete blocks designed for retaining walls
  • Landscape fabric
  • Stakes
  • String
  • Stone dust and crushed stone
  • Perforated drain pipe (Optional)


How to Build a Concrete Block Retaining Wall

  1. Decide Location and Start Digging

    Decide roughly where you want the retaining wall to be and dig back 2 feet from there into the slope; stretch landscape fabric over the slope to keep dirt from falling into the backfill you'll be applying later.

  2. Use Stakes and String to Mark Wall Dimensions

    With this soil removed, mark precisely where the retaining wall will be, using stakes and string, with the string resting at what will eventually be the top of the wall.

  3. Dig a Trench

    Under this line, dig a trench 2 inches deep and wide enough to accommodate your blocks.

  4. Check Leveling

    Ensure the base is level using a screed and a carpenter's level; tamp it down.

  5. Layer Stone Dust

    Apply about 2 inches of stone dust for your first course of blocks to rest on; tamp it down.

  6. Remove the Flanges From Bottom Layer of Blocks

    With a hammer and chisel, knock the flange off the blocks you'll be using for the first course (you don't need it here; without it, the blocks will rest more evenly on the ground).

  7. Lay Block on Top of Base and Check Leveling

    Lay a block on this base at one end of your retaining wall. Check with your carpenter's level to ensure that it is level, both left-to-right and front-to-back.

  8. Lay Next Blocks on the First Course

    Repeat with the second block, laid down next to the first one. Not only must it lie perfectly even in its own right, but it must also align perfectly with the first block. Continue in this way to complete the first course.

  9. Lay the Subsequent Courses

    Lay the second course in the same way. But, here, you must stagger the joints so that the "cracks" in the second course don't align with those in the first course. Because this will necessitate having half-blocks at each end, you must have a tool on hand for cutting blocks.

    Continue to lay courses that are perfectly level, with staggered joints, until the necessary height is reached.

  10. Backfill With Crushed Stone

    Backfill with crushed stone as you go for added stability.

How Is a Retaining Wall Used?

One of the most common functions of a retaining wall is to stop erosion on hillsides where growing plants to control erosion is either undesirable or impractical. But you are underestimating the possibilities for these structures if you see them only as erosion fighters.

Consider changing your property's "lay of the land" when erecting a retaining wall. A sloping and unusable area can be leveled off (behind the wall) to create an outdoor living space, such as a patio or new garden beds.

For a different look, erect a series of smaller retaining walls rather than one large structure, and terrace the hillside. Use the terraces to show off eye-opening flower beds.

When to Call a Professional

You can make a 3-foot-tall concrete block retaining wall if you have average DIY skills and a reasonably strong back. But anything taller should be left to professionals. Not only will they have the engineering skills for the job, but they will also be up to speed with relevant building codes in your area.

Also, any significant runoff issues in your area require an expert with a strong understanding of engineering considerations.

How Often to Replace a Retaining Wall

A retaining wall should last between 25 to 100 years. However, you need to maintain it to expect longevity. The key to maintenance is routine inspection. Remove any rocks or debris that may block drainage pipes (if you have them).

If soil erodes away behind the wall, leaving gaps, fill in those spots with fresh soil. Pooling water can erode the concrete blocks.


Consider using plantings behind the wall. Plant roots help keep the soil in place, reducing erosion. If the plants die in winter, replace them in the spring.

Look for cracks or shifting blocks. Also, pay attention to any bulging or bowing of the wall. Contact a professional for assistance remediating any damage.