- Things to Consider. Depending on the wall’s height and your location, you may need a building permit to install a retaining wall.
- Plan the Location. Using a tape measure, decide the length and the width of your retaining wall. ...
- Dig a Trench and Level the Ground. The success of your retaining wall depends on a level base. ...
- Lay the Base. Due to soil erosion, your retaining wall should be built on a solid foundation made from gravel. ...
- Lay the First Course of Blocks. It’s time to start laying the retaining blocks on the sturdy base you just created. ...
- Cut End Blocks. The blocks should be staggered, so you’ll need to cut the end blocks of each even-numbered course in half.
- Lay Additional Courses. By installing an even first course, you’ve successfully laid the groundwork for more courses. Here’s how you lay the next levels of interlocking wall blocks.
- Install Drain Pipe (Optional) If you get heavy rains, install a drainage pipe behind the wall. ...
- Backfill the Wall. Once you’ve laid all the courses of blocks, you can fill in the area behind the wall. Backfill the wall with gravel or sand.
- Finishing Touches. Put down a layer of capstone blocks to complete your retaining wall and enhance the overall aesthetic.
How do you build a retaining wall step by step?
To build a retaining wall, begin by planning and marking out where you want your wall to be. Dig a trench, then tamp down the soil and lay a base layer of rock dust. Lay the foundation on this base and use a rubber mallet to level the blocks.
How do you level ground for a retaining wall?
Hold a level on the string and move the string either up or down on one of the stakes so it is level. Measure the distance from the string to the ground in various areas to determine where the ground's lowest point is. Dig a hole approximately 4 inches more than the retaining wall blocks' thickness and 24 inches wide in the ground's lowest point.
What do you do when it rains on your retaining wall?
If you get heavy rains, install a drainage pipe behind the wall. It may be easiest to do this when you’ve only installed one or two courses. Use a perforated corrugated pipe . The pipe should extend behind the entire length of the wall and drain somewhere the water can exit the area.
How do you prepare soil for a retaining wall?
0:542:43How to Prepare for a Retaining Wall - Site Excavation - YouTubeYouTubeStart of suggested clipEnd of suggested clipIf organic or wet soils are still present in the base trench area or under the infill soil they mustMoreIf organic or wet soils are still present in the base trench area or under the infill soil they must be removed to replace with granular. Material.
How deep should a base be for a retaining wall?
The general rule of thumb is to bury about one-eighth of the height of the wall. For example, if your wall will be three feet (36 inches) tall, the first course of blocks should start five inches below soil level. The gravel base should start three inches below this.
What is the best backfill material for a retaining wall?
gravelThe best material for the backfilling of a retaining wall is gravel, and it should be well graded. The main reason for using gravel is because it does not retain water (small void ratio); hence lateral loads experienced will be minimal. You should also have weep holes for draining excess water that may be retained.
How much slope before a retaining wall is needed?
All retaining walls should lean into the hill 1 inch for every 12 inches of height. Timber walls 4 feet or higher should be tied to the hillside with "deadmen" anchors (6-foot-long, T-shaped tiebacks buried in the hillside) attached to the wall every 8 feet, extending 6 feet back to a 2-foot-wide T-bar.
What do you put under a retaining wall?
Due to soil erosion, your retaining wall should be built on a solid foundation made from gravel. Choose gravel that has stones sized between 1/2-inch and 3/4-inch. Fill the trench with a 2- to 3-inch layer of gravel.
Do you need gravel behind retaining wall?
Gravel Backfill Do you need drainage behind a retaining wall? Yes, which means you need backfill too. This backfill is the soil that's located in the first 12 inches of space right behind the retaining wall in order to have proper drainage, and it can be either gravel or crushed stone.
Do you need drainage behind a retaining wall?
Every retaining wall should include drainage stone behind the wall. Though it is a good idea to install a drainage pipe on all walls, there are certain situations where a perforated drain pipe is absolutely necessary.
Do you need landscape fabric behind retaining wall?
You should use landscape fabric behind a retaining wall because the fabric supports the bricks, wood, or other materials that make the wall. Wet soil can push against a retaining wall, weakening it. By placing a strip of landscape fabric under the soil, the wall won't have as much pressure on it.
Does a retaining wall need a footing?
The key to building a strong and durable retaining wall is a stable footing and proper drainage. A retaining wall needs a footing because if the ground below it shifts, the wall will shirt too and possibly collapse.
How steep can a slope be without retaining wall?
The maximum slope for the soil you can safely go without a retaining wall is 35 degrees, especially if the soil is granular. If the angle is steeper, you will need a retaining wall to keep everything in place.
How do I grade my ground away from my house?
Ideally, the ground should drop one inch for every one foot that you move away from the house for the first 5-to-10 feet around your house. While this is not always possible, the ground should never be sloping upwards as you move away from your house foundation.
What is the cheapest retaining wall?
The cheapest type of retaining wall is poured concrete. Prices start at $4.30 per square foot for poured concrete, $5.65 for interlocking concrete block, $6.15 for pressure-treated pine, and about $11 for stone.
How wide and deep for a footing be for a retaining wall?
Usually concrete retaining wall footings are rectangular in shape. The average size footing we build is about 1 foot deep by 2 foot wide. But sizes may vary based on the wall material, height and soil conditions.
How big of a footing do I need for a retaining wall?
The footing dimensions will largely be determined by the size of the wall. A poured concrete footing for concrete, block or brick walls should be at least twice as wide as the planned wall. The footing should be at least as thick vertically as the wall's planned width.
How deep should a footing be for a wall?
All footings should be a minimum of 150mm (6") in depth, with the bottom 350 - 400mm (14-16") below ground level on most soils. For clay soil however, thicker and deeper footings should be used.
Does a 2 foot retaining wall need a footing?
The key to building a strong and durable retaining wall is a stable footing and proper drainage. A retaining wall needs a footing because if the ground below it shifts, the wall will shirt too and possibly collapse.
Why do we need retaining walls?
Building a retaining wall will help reduce erosion, improve water drainage, and create usable garden space. It's a great home-improvement project that can be completed in a weekend whether you're a novice or an old hand.
How high should a retaining wall be?
Continue until retaining wall is its preferred height. If your wall is over 3 ft (.91 m) in height, you should offset each new row slightly back from the row below it, like very shallow stair steps. This will make your wall more stable and help create a better hold with the soil once you backfill.
How to build a wall with a shovel?
Excavate the site. Using a shovel, dig a trench along the line you have laid out. It should be slightly wider than the blocks you will use for your wall, or about 1 foot (30 cm). [2]
What to use for backfilling blocks?
Use crushed stone or gravel for backfill on your first layer of blocks. This will provide excellent support, keeping your bottom layer from slipping back with time and erosion.
How to make a random outline for a wall?
If you want more of a random outline, lay out a line for your wall using a garden hose. Simply drape the garden hose out in the general area of the proposed wall utilizing its curves. Check to see that the shape is buildable and aesthetically pleasing, and then use landscaping paint or flour to mark the ground where the garden hose was.
How to make a wall with a staggered pattern?
1. Start your second layer with a staggered pattern. This is so that the top layer seams are offset with the bottom layer. You want each layer of blocks to be different from the one below it. For example, if the wall has straight edges on the ends, the next layer should start with a block that has been cut in half.
How to cut a block for a sandbox?
Cut individual blocks to complete the first layer, if necessary. Simply mark them at the appropriate length and cut with a mason 's saw . Always use proper protection when cutting.
How deep should a retaining wall be?
The exact depth of the trench depends on the proposed height of the wall, but follow this rule of thumb: Dig a trench to be an eighth of the wall plus three inches. For example, if you want the finished height of your retaining wall to be three feet (36 inches) tall, you’d need to dig the trench eight inches deep to accommodate three inches ...
How much soil pressure does a retaining wall need?
Soil is heavy, especially when soaking wet from a recent rainstorm, so a basic retaining wall (four feet tall and 15 feet long) potentially has to support up to 20 tons of soil pressure.
What happens when a retaining wall saturates?
When it saturates clay-type soils, they swell and put excessive pressure on the backside of the wall. To avoid failure, make drainage provisions at the same time as you go about building the retaining wall.
What materials are used to build retaining walls?
Retaining walls can be constructed using a variety of materials, from poured concrete and large timbers to natural stones, even bricks. For DIY purposes, opt for manufactured blocks that are designed specifically for building retaining walls; a locking flange along the bottom edge creates a secure attachment between rows.
Can you build a retaining wall short?
Shorter retaining walls, however, can be constructed by enthusiastic do-it-yourself ers equipped with some basic construction knowledge. Does that sound like you? If you’re looking to get your hands dirty and enhance your landscape with a retaining wall, these guidelines for building a retaining wall will help you get off to a good start.
Step 1: Install Stakes and Attach String
Hammer wooden stakes into the ground, one at either end of where the retaining wall will be. Extend a string of twine between the two wooden stakes and tie one end to each stake, pulling the string taut before tying it.
Step 2: Level the String
Hold a level on the string and move the string either up or down on one of the stakes so it is level. Measure the distance from the string to the ground in various areas to determine where the ground's lowest point is.
Step 3: Dig Retaining Wall Trench
Dig a hole approximately 4 inches more than the retaining wall blocks' thickness and 24 inches wide in the ground's lowest point. Continue to dig the trench, following the string. The trench will remain consistently 24 inches wide; however, the depth will vary slightly.
Step 4: Tamp Soil and Add Gravel
Compact the trench with a tamper. Pour a 4-inch layer of 3/4 minus gravel into the trench. (Three-quarter "minus" gravel means that the gravel should be no larger in diameter than 3/4 inch.) Use a level to ensure the gravel is level and use the tamper to compact it.
Step 5: Add Sand and Wall Blocks
Pour a 1-inch layer of sand over the gravel and compact this as well. Start at one end of the retaining wall and begin placing the retaining wall blocks in the trench. Set a level on each block and check for levelness both front to back as well as left to right. Hit the block with a rubber mallet to lower any high areas into the sand base.
Step 6: Add Second Row of Blocks
Set a second row of retaining wall blocks on the first row. Use the level to ensure each block is level. If the first row is level, the second row should automatically be level unless there are inconsistencies in the blocks. Continue to build up your retaining wall to the desired height.
Step 7: Pour Gravel and Spread Fabric
Pour crushed gravel behind the retaining wall blocks to increase drainage. Make the gravel's surface level with the bottom of the final retaining wall block row. Cut a strip of landscape fabric to cover the gravel. Pour topsoil over the landscape fabric until it almost reaches the retaining wall's top edge.
Why do you need a retaining wall?
Building a wood retaining wall helps to reshape slopes on your property to create level areas for driveways, gardens, paver patios, children's play areas, and decks. Retaining walls also keep soil and vegetation away from established structures.
How high is a 16 foot retaining wall?
This project will produce a straight, 16-foot long, wood retaining wall that is 24 inches high. The construction method used is suitable only for low walls of a maximum of 30 inches. Taller walls require a different type of structure. For durability, use only pressure-treated lumber rated for ground contact.
How are post holes dug?
Instead, post holes are dug in the same way as you would dig holes for fence posts. Pressure-treated boards are then nailed across the backs of the posts, much like boards on a fence.
How wide is a sandbox post?
Instead of making the distance 192 inches (16 feet), you'll be making it 186.5 inches to account for the width of the two end posts. Each end post is 5-1/2 inches wide.
How to make a post for a fence?
Cut each of the two-by-six posts in half, so that you have eight posts, each 4 feet long . Daub the cut ends of the lumber with wood preservative. Place the posts in each hole. Working one post at a time, use the laser level to make sure that the post is aligned perfectly plumb.
Can you build a retaining wall with masonry blocks?
Yet retaining walls that use masonry retaining wall blocks or those made from thick timbers can be difficult to build because of the overly heavy materials. As long as the height of the retained soil stays fairly low, you can build another type of wood retaining wall that uses lighter weight dimensional pressure-treated lumber.
Do you need tie backs for a low wood retaining wall?
Basics of Low Wood Retaining Walls. A low wood retaining wall does not need unwieldy tie-backs dug back into the slope, like many of the four-by-four timber retaining walls. Nor does this wall rely on sheer weight, plus a slight tilt, to hold back the slope, as do masonry walls. Instead, post holes are dug in the same way as you would dig holes ...
Things to Consider
Depending on the wall’s height and your location, you may need a building permit to install a retaining wall. Check your local building codes and restrictions, as well as your homeowner's association (HOA) restrictions.
Plan the Location
Using a tape measure, decide the length and the width of your retaining wall.
Dig a Trench and Level the Ground
The success of your retaining wall depends on a level base. To create a solid foundation, dig a trench for the first course of your interlocking retaining wall blocks. Make sure the ground remains even throughout.
Lay the Base
Due to soil erosion, your retaining wall should be built on a solid foundation made from gravel.
Lay the First Course of Blocks
It’s time to start laying the retaining blocks on the sturdy base you just created.
Cut End Blocks
The blocks should be staggered, so you’ll need to cut the end blocks of each even-numbered course in half. For example, the second and fourth courses should have half end blocks, while the first and third courses should have full end blocks.
Lay Additional Courses
By installing an even first course, you’ve successfully laid the groundwork for more courses. Here’s how you lay the next levels of interlocking wall blocks.
