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The Ultimate Rock Retaining Wall Guide

Retaining walls are vertical or nearly vertical structures that are used to keep material on one side from falling, sliding, or eroding. They support the terrain in which the angle of the rest of the ground is surpassed and otherwise it will fall into a more natural shape.


It is a structure to resist the lateral pressure of the soil when the soil level is required to adjust beyond the soil resting angle. These walls are used to support soil on both sides so that it can be preserved at various levels. 


These are structures that are used to hold soil in place on a slope that it does not normally follow (typically a steep, near-vertical, or vertical slope). They are commonly used to connect soils between two different elevations in areas of terrain with unfavorable slopes or in areas where the landscape must be sculpted and constructed for more specific purposes such as hillside farming or highway overpasses.

Benefits Of A Retaining Wall

A retaining wall has a variety of advantages, including reducing soil erosion and increasing the value of your home. Several of these advantages are likely to pique your interest and assist you in deciding if a retaining wall is the best next move for your landscaping improvements.

Flood Control With A Retaining Wall

The unexpected floods that sometimes pass across Southern Utah are one of the problems that people don’t often predict. St. George and the surrounding cities, like most desert towns, are vulnerable to flash flooding, which can cause major property damage if you are not prepared.

You can protect your home and property from flooding damage by using the right retaining walls. If you’re not sure if your property is at risk, use the Utah government survey’s flooding hazard map to double-check.


A retaining wall has the added advantage of enhancing the design of your house, which would possibly contribute to an improvement in market value.

If your front or backyard is sloped, it doesn’t have to be an eyesore or a waste of space—installing a retaining wall is the best way to make good use of your land while still creating a neat and tidy space.

There will be a retaining wall option out there that will perfectly fit your house, regardless of its age or design. Retaining walls are available in a number of types and materials, such as wood and concrete. We’ve helped countless clients find the ideal retaining wall for their land, needs, and budget at Amazing Fencing

Increasing the Usable Space in Your Yard

While hills and mounds can be attractive in and of themselves, they can also take up a lot of space and be difficult to landscape. You can add more functional space to your yard by building terraces using a series of retaining walls, which can then be used for planting. Terracing also provides an intimidating and appealing façade for your yard, which can be used to highlight various features such as patios and gardens.

Assists in the diversion and use of rainwater

Rainwater that would otherwise be drained can be diverted and used for better purposes in your home gardens and grass turf by using a creative design in constructing a brick retaining wall. You can funnel rainwater into a collection system using a retaining wall, which can then be used to water your garden and lawns.

Environmentally friendly

Since they cause minimal damage to natural vegetation and help minimize stormwater runoff, retaining walls are an environmentally-friendly choice. They’re usually made of environmentally friendly materials that are inexpensive, long-lasting, and fit in with your home’s natural surroundings.

Retaining walls need very little maintenance, particularly if they are built properly. You should leave the wall alone until it’s designed to your taste. Natural retaining walls, such as rocks, can withstand severe weather conditions. When you build walls out of natural materials, you have access to locally, inexpensively, and environmentally friendly available materials, even when you need to fix them.

Acts As A Sturdy Property Boundary

There are occasions when a clear boundary between your property and your neighbors is needed, and a simple fence is insufficient. Perhaps they are encroaching on your property, or perhaps people are climbing your fence to gain access. In either case, a retaining wall will act as a solid and recognizable property boundary, deterring anyone from taking advantage of your ground.

Sink Holes Are Prevented

Sinkholes can form over time in geographical areas where water dissolves carbonate rock slowly. This would inevitably result in a void under the surface area. Depending on the rate of degradation, the sinkholes may be small or big. These sinkholes are harmful to the building, and once they appear, they are difficult to repair. As a result, these retaining walls protect the landscape system from sinkholes.

Seating Area is Created

Since most retaining walls are lower in height, they can be used as a chat, reading, or relaxing place in the yard. It offers a convenient seating area from which you can enjoy the pleasures of bird-watching, watching your children play, or even watching a stunning sunset without having to invest in additional yard furniture.

What Is A Rock Retaining Wall

This type of retaining wall creates a barrier with strategically placed rocks or boulders to keep a bank of soil in place. On parts of the trail where the Treadway is unstable and erodes down the side slope, retaining walls are designed to keep the tread in place. These are usually placed where the trail was constructed along a river embankment or with very steep side slopes. 

A well-constructed rock retaining wall is one of the most robust and attractive trail structures. Build these walls with the hope that they would last a century or more. To build a strong rock retaining wall, you’ll need a lot of materials and time. Individual retaining wall rocks or boulders will be carefully selected and placed one at a time to ensure optimum durability for the entire structure.

 The common material used for rock retaining walls is.

  • Sandstone
  • Bush Rock
  • Bluestone
  • Porphyry Rock

Factors To Consider Before Constructing A Rock Retaining Wall

Informing The Authorities

You can build a short wall if you have a basic understanding of masonry. If the wall is taller than four feet, it is recommended that you hire a professional. Water flow can be affected by retaining walls, which can have an impact on your neighbors and the environment. As a result, before starting the project, you should consult the authorities and submit your plans.

It’s also a good idea to call organizations whose main aim is to alert the authorities in your region that you’re planning a dig on your land. They should notify you of any underground cables and lines in the area and mark their precise positions.

Choosing The Location

Make sure you have a clear understanding of property boundaries, as well as both above ground and underground infrastructures, such as stormwater drainage systems and irrigation, before deciding on a position for your wall. Other things to think about when choosing a venue include:

  • Where would you store additional infill that must be brought to the site if your wall is on a slope?
  • Where would the excess soil be deposited if you’re digging through a hillside?
  • Drainage patterns are found in nature. A retaining wall, depending on its height, can obstruct natural drainage patterns and have downstream environmental implications.
  • Will the reinforcement machine encroach on the property line if the wall runs along the property line?
  • Will there be any additional weight or vertical forces, such as fencing, guardrails, driveways, parking lots, or swimming pools, above the wall? Don’t overlook the need for temporary construction equipment.

Examining The Soil

The soil that forms the foundation, or base, must be tested to ensure that it is solid enough to support the wall. The type, bearing capacity (soil’s ability to support a load), stress parameters, and friction angle (resistance to movement) of the soil used for the foundation and reinforced zone, as well as the retained soil zone, should all be determined.

The base soil should be firm, solid, and strong in general, and it should not be damp. Infilling wet soils, such as clay soil, is also not recommended. They’re still wet, so any extra moisture won’t be able to get through to the drainage channels. Wet soil can also expand and contract in freezing temperatures, causing damage to the wall. Sandier soils, on the other hand, allow for better drainage. Examine the geotechnical report for information on on-site soils, vast soils, weak chemical properties, groundwater levels, and more.


To begin the design, you’ll need to figure out the corresponding wall heights, footprint sizes, slopes, and setback angles, all of which are affected by the site’s elevation and grade. You must also remember that the retained material would inevitably shift downslope due to gravity. This should be addressed in the design to reduce the amount of lateral earth pressure behind the wall, which, if it reaches its full value, will cause the wall to topple. The height of your wall is determined by the soil and slope, setback, and block size.


The pressure against the wall caused by water or soil moisture buildup behind the wall causes most retaining walls to collapse. Back-of-the-wall water should be able to freely drain down and away from the wall on both walls. Gravel backfill, drainage blankets, and drain pipes are used to achieve this. Weep holes are needed in structural walls to enable water to drain from behind the wall.

Groundwater is the biggest enemy of retaining walls, particularly if the soil in your yard is clay soil. If the clay soil is saturated with groundwater, it will swell and place too much pressure on the wall. Make drainage provisions to ensure that your yard is turned for good and that you won’t have any issues in the future. This can be achieved by inserting a perforated pipe at the wall’s ends or with the help of weep holes.

Building a rock retaining wall

A rock retaining wall is normally built by a contractor or other tradie due to the weight of the boulders, but if you’re confident in your construction skills, you may be able to do it yourself.

What You Will Need


  • Stakes made of wood
  • A hammer
  • Line height
  • Shovel
  • Knife 
  • Rake 
  • 2×4 shortboard
  • Hand tamps 
  • Carpenter’s level, 4-foot


  • Landscape fabric made of fieldstone or cut stone
  • Gravel that compacts
  • Sand that is coarse in texture.
  • Gravel for drainage
  • Adhesive for masonry (optional)

Steps To Follow

Determine the exact location of the retaining wall.

Excavate the bank to a depth of 2′ deeper than the planned front of the wall and layout it at the retaining wall’s location.

Dig a base and level it

Dig a footing that is roughly 2′ wide and at least 8″ deep. Using a line level or a long bar level, make sure the base of your footing is leveled.

Loose Soil Compacted

Make sure not to disturb the dirt at the bottom of the footing. If the soil is loose, compact it with a plate tamper or a shovel.

Move the footing down by creating a shelf where the footing would be lower if the height of the footing drops more than approximately 6”. This maintains the level of the footing while also following the grade.

 Pour in the footing

With a plate tamper or shovel, cover the entire footing with coarse gravel, spreading it thinly and compacting it.

Leveling the footing

Using a long level or a line level, level the top of the gravel footing. Using a garden rake and a plate tamper, smooth the soil.

To increase accuracy over long distances, use a spinning laser and receiver.

Start with the first row of rocks.

Place the first row of rocks, facing outward, with the desired boulders.

Place the flattest side of the boulders on top. This will make fitting the next layer much simpler.

Install the Second Boulder Layer

Go on with the second sheet, making sure the wall is leaning back towards the bank. The wall should have a backward angle of 1/2″ to 1′ in the ideal situation.

When you rotate longer stones to face into the bank regularly, you’ll have more fit choices and the wall will be more stable until backfilled.

Placement of the Landscape

Cover the back of the wall and the dirt bank with a soil-blocking cloth. Make sure there is enough cloth to cover the soil on the top of the wall.

Placement of the Landscape

Cover the back of the wall and the dirt bank with a soil-blocking cloth. Make sure there is enough cloth to cover the soil on the top of the wall.

Backfilling Soil To Wall

Fill the gap between the wall and the bank with a coarse stone, stopping about 8″ below the wall’s tip. Backfill the soil to the wall with the remaining cloth.

How much does it cost to build a retaining wall?

The following factors will influence the price of your rock retaining wall:

  • Its height, width, and length
  • You choose the kind of retaining wall rocks you want to use.
  • Design considerations, including excavation and drainage
  • If you create it yourself or employ someone to do it for you

Small rock retaining walls can be constructed for under a thousand dollars, but more elaborate structures can cost tens of thousands of dollars. If your rock retaining wall requires council approval and structural diagrams, expect to pay more because you’ll be responsible for these extra costs.

Expect to be quoted on the basis of materials and labor, with materials being measured per square foot. The cost of retaining wall rocks or boulders is expected to be:

  • For unselected rock, prices range from $140 to $250 per square meter.
  • For higher quality cut sandstone, expect to pay $180 to $280 per square meter.
  • A grade cut sandstone costs between $280 and $500 per square meter.

The look of a hand-placed boulder or stone retaining wall is rustic, but it has more definition than a loosely-placed version.


To summarise, Retaining walls are low-maintenance, highly functional, space-saving, eye-catching, and environmentally friendly, especially when designed and built properly. Building a retaining wall may be done with a variety of materials. Professional assistance will ensure that your retaining wall is properly designed and constructed. A retaining wall built with the required material will give your home a pleasing appearance. Rock retaining walls can withstand extreme weather conditions.

When you create walls out of natural materials such as rocks, you have access to locally available materials even when you need to repair them. It can also be used to build a high-impact entrance, with a terrace for growing flowering plants and a gateway to the house.

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