- Backfill the wall with gravel or sand. If you use sand, first cover the backside of the retaining wall with landscape fabric. ...
- If you’re backfilling with gravel, you can pour the gravel after every course you lay. This will give the gravel time to settle.
- Shovel in the backfill material in small portions. Tamp it down as you go, ensuring there are no hollow areas and it settles completely.
- Backfill up until slightly below the height of the wall.
- Fill the remaining space with sod or topsoil for growing grass or other plants.
How do you cover a retaining wall with landscape fabric?
Lay down landscape fabric behind the wall, leaving enough excess to reach the top of the block. Fill in directly behind the wall with gravel as you build. For the last two rows of full block, apply concrete adhesive to the wall block tops and then set the next row of block in place.
How do you build a concrete wall behind a retaining wall?
Fill in directly behind the wall with gravel as you build. For the last two rows of full block, apply concrete adhesive to the wall block tops and then set the next row of block in place. If you're adding block caps, apply adhesive to the top row of block before placing the caps. Fold the excess fabric back.
What can you do with a retaining wall block?
Define a driveway, sidewalk or walkway with a course of retaining wall block, or beautify them by lining them with raised flower beds. Incorporate a raised bed into a backyard pond or water feature. Beyond standard retaining wall ideas, consider other uses for retaining wall block.
What is the best material for retaining wall?
Retaining walls can be made from wood, bricks, natural stones or concrete blocks. For DIYers, it’s best to use concrete retaining wall blocks, which can be interlocking and are heavy enough to stay in place without cement or other adhesive.
What should I put under my retaining wall?
Backfill the wall with gravel or sand. If you use sand, first cover the backside of the retaining wall with landscape fabric. This will keep the sand from seeping between the blocks. If you're backfilling with gravel, you can pour the gravel after every course you lay.
What goes behind retaining wall?
Backfill refers to the dirt behind the wall. In order to provide proper drainage, at least 12 inches of granular backfill (gravel or a similar aggregate) should be installed directly behind the wall. Compacted native soil can be used to backfill the rest of the space behind the wall.
Does a retaining wall need a base?
The foundation of a retaining wall is a key component in the wall's longevity. A good foundation ensures the wall does not sag or settle. It will ensure the finished wall is level and straight.
How do you prepare the ground for a retaining wall block?
0:542:43How to Prepare for a Retaining Wall - Site Excavation - YouTubeYouTubeStart of suggested clipEnd of suggested clipThe minimum width for a base trench is 24 inches the depth of the trench is determined by allowingMoreThe minimum width for a base trench is 24 inches the depth of the trench is determined by allowing for six inches of base material. Plus one inch per foot of wall height.
Do you have to put gravel behind a 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.
What kind of gravel goes behind retaining wall?
crushed stoneOur experts prefer crushed stone for the base rather than naturally occurring gravel dug from a pit. Crushed stone is a little more expensive. However, it provides better drainage, and because of the sharper angles on the stone, it requires less compacting, and once it's compacted, it stays that way.
Do you need landscape fabric under 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 retaining wall need 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 deep should a footing 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.
How do you build a base for a retaining wall?
Base PreparationTo start your layout, place stakes to represent the location of the front of the retaining wall. ... Excavate the area by removing all surface vegetation and organic materials from the area. ... If reinforcement is needed excavate behind the wall to accommodate the design length of the geogrid.More items...
Does a 3 foot retaining wall need drainage?
If your retaining wall needs a drainage pipe, make sure the pipe has slots on all sides, not just one. A drainage pipe might be needed if: The retaining wall is at least four feet high or taller. Clay or other poor draining soils are behind the wall.
How much gravel do I need for a retaining wall?
Multiply the length of the wall by the desired height, then divide this number by 81 to determine the amount of backfill gravel needed. Add the backfill amount to the base amount to determine the total cubic yards of gravel necessary for completing the wall.
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.
What is the best material to backfill a foundation?
Coarse-grained soil: Your first option is coarse-grained soil. This is a mixture of gravel, sandy soil, and a negligible amount of fine materials. This is a high-quality backfill since it provides fine support for the foundation and is pretty easy to compact.
How do you install drainage behind a retaining wall?
All walls should include drainage stone, even if they don't require a drain pipe. Install drainage stone at the back of the retaining wall and extend 12-in behind the blocks. Start the drainage stone near the base of the wall and extend up to within 6-inches of the top of the wall.
Do all retaining walls need drainage?
All retaining walls should include drainage stone even if a draining pipe is not required.
How deep should a retaining wall trench be?
It should be 24 inches wide in most cases—this is the standard width of retaining walls. The depth of the trench should be six inches , plus an additional inch for every foot of wall height. You can then compact the base trench by making a couple passes with a plate compactor.
How wide should a wall be?
Moving forward, you should start from the lowest point to dig a base trench for the entire length of the wall. It should be 24 inches wide in most cases—this is the standard width ...
Where should drain pipes be located?
The drain pipe should be located at the lowest possible position near the back of the trench, and should have venting to daylight every 50 feet (15 meters). There should be a minimum of six inches of wall rock placed in the base trench, which should then be raked smooth upon filling.
When you finish preparing a base, can you move on to installing the base material?
Once you’ve finished these steps for preparing the base, you can then move on to installing the base material.
Is a retaining wall strong?
Published by Writer Leave your thoughts. A retaining wall is only as strong as its foundation. Before you can start building up the blocks of your retaining wall, it’s crucial that you give plenty of attention to the base. Here’s an overview of what you need to know about preparing the base for your retaining wall so it will last you ...
Planning a Block Retaining Wall
There are several retaining wall systems to consider when choosing the building materials for your wall. You can choose regular block that simply stack together for a gravity-held wall, a block system that works with pins for easy and secure assembly or block with an interlocking lip as we did for this project.
Prep and Lay the Retaining Wall Block
Now that you have a plan and a layout, prep the area and begin building the retaining wall.
Retaining Wall Ideas
Once you know how to build a block retaining wall, think about some different DIY landscape ideas for retaining walls.
Why do we need retaining walls?
A retaining wall is intended to hold back soil when there is a drastic change in elevation. Often retaining walls are used to terrace yards that originally had a steep slope. Additionally, retaining walls can help create usable outdoor space as well as control erosion, (see Landscaping a Split-Level Home .) Low retaining walls are frequently used ...
What is a backfill for retaining walls?
Backfill. Second, a retaining wall must have properly compacted backfill. Backfill refers to the dirt behind the wall. In order to provide proper drainage, at least 12 inches of granular backfill (gravel or a similar aggregate) should be installed directly behind the wall.
How high should a retaining wall be?
Typically, residential retaining walls are built between 3 and 4 feet high.
What is the best base for a wall?
The taller a wall is, the further below ground level it should be set. Crucial for supporting the rest of the wall, a good base is made of compacted soil and at least a six inch layer of compacted sand and gravel.
What happens if water goes unaddressed behind a retaining wall?
When drainage goes unaddressed hydrostatic pressure will build up behind the wall and cause damage such as bulging or cracking. There are a number of ways to ensure proper drainage of water from behind a retaining wall. First, is to make sure your landscaping contractor backfills at least a foot of space behind the wall with gravel.
What type of rock is used for retaining wall?
Rock screenings, 3/4″ minus, crush and run (or ABC stone), paver base, 3/4″ crushed rock, #57 or #78 stone, and Class I, II, or III backfill are all acceptable forms of base material. Do not use smooth river rock, pea gravel, or uniform sand for the base material. Round material like this does not hold its shape, is difficult to compact, and will make it difficult to level the blocks. Rock screenings or minus material make leveling the initial retaining wall blocks easier, but clean crushed rock will perform just as well if not better over time.
What grade of rock should I use for walling?
Wall rock must be angular. This eliminates pea gravels and river rock. I recommend a well graded compactable aggregate that is 0.25″ – 1.25″ ideally. This includes 3/4″ crushed rock, #57 or #78 stone, clean crushed limestone, or Class I or II backfill.
What type of stone should I use for drainage?
Drainage stone must allow water to drain through. The amount of fines (material passing through a No. 200 sieve) should be less than 10%. You may be tempted to use pea gravel or river rock as drainage stone. However, the smoothness of this material will make it difficult to retain at the end of the wall or if you ever need to remove a block. In addition, smooth material is difficult to compact. I recommend a well graded compactable aggregate that is 0.25″ – 1.25″ ideally. This includes 3/4″ crushed rock, #57 or #78 stone, clean crushed limestone, or Class I or II backfill.
How much crushed rock is needed for a truck?
If the quantity of crushed rock exceeds 1/4 cu. yd. (6.75 cu. ft) and you have access to a truck, research landscape supply companies such as this one in Raleigh. A 1/4 cu. yd. is typically the minimum order amount at a landscape supply company. You will pay a fraction of the price compared to a typical home improvement store. Landscape supply companies will also deliver for larger quantities, typically over 5 cu. yds.
What is wall rock?
Wall Rock. Wall Rock is only applicable to block walls. This refers to the material used to fill hollow blocks. This adds weight to the retaining wall while keeping the blocks themselves relatively light. It also aids in friction resistance between the blocks. This is an essential component to hollow blocks.
Can you use clay in a backfill?
Do not use clay, organic material such as decomposing mulch, garden soil, top soil, or any other soft soil. If you need to purchase backfill, look for processed fill, gravel, sand, or screenings. The base material, wall rock, and drainage stone all require a quarried backfill.
Can you backfill a wall with a fill site?
Retained Soil. If your wall is on a fill site, you will need additional backfill behind the drainage stone. Ideally, you will want to use what you have on your property, but this is not always possible.
How to stop filling a trench?
Stop filling the trench once the gravel level reaches 2 inches below ground level behind the wall. Smooth the surface of the gravel with the shovel or a rake until it is evenly flat. Cover the gravel with 2 to 3 inches of the displaced soil from the trench.
Why are retainers important?
Whether the wall is made from stones, bricks or wood, it is important to provide a barrier between the building blocks and the soil. says KG Landscape. Loose soil may penetrate the small open spaces between the wall's layered materials, giving the wall an untidy appearance, forcing the individual parts apart or causing weeds to grow out of the wall. Landscape fabric is thin and sturdy and is a simple way to preserve a retaining wall's construction.
How to make a trench with landscape fabric?
Place one end of the landscape fabric down into the trench. Push the fabric down until the edge rests on the bottom of the trench. Lay the top edge of the fabric over top of the wall. Place a heavy object, like a rock or wooden block, on the top of the fabric to hold it in place on top of the wall. Repeat this process until the entire length ...
What is the backfill for retaining walls?
Backfill simply refers to the soil directly behind the wall. For proper drainage, the first 12 inches of space behind a retaining wall should be filled with crushed stone or gravel. This is so that when water gets into the space, it does not become bogged down in soil but instead can flow down the wall to the drains or weep holes. Many designs allow for the top six inches of space behind a wall to be filled with native soil, so that the area can be used for planting.
Why is drainage important for retaining walls?
Why Proper Drainage is Important for Retaining Wall Performance. A retaining wall is built to hold back a certain amount of soil. The design of a properly-built retaining wall resists the force of the soil behind it and prevents caving, buckling, or leaning. However, retaining walls are built with a certain capacity in mind.
Why do retaining walls fail?
Retaining walls are useful and attractive features in many yards, but they are prone to failure if proper drainage is not considered. Some professional installers find that nearly 80 percent of the retaining walls they see fail at some point due to improper drainage. Whether you are planning to install your own retaining wall or have someone else ...
What happens when water gets behind a wall?
When water gets behind the wall, it puts additional pressure on the structure, which can result in the overall force exceeding the wall’s ability to resist. This is what good retaining wall drainage looks like: When the wall is no longer able to resist the force behind it, the weakest part will give.
Why does a wall buckle?
In other cases, water pressure behind the wall may cause it to lean outward. If the pressure is consistent and forceful enough across the wall, it may even buckle.
Should retaining walls be installed when it rains?
Ideally, retaining walls should not be installed when it is likely to rain. If this cannot be avoided, the use of tarps will help to keep the water out of the area when construction is not actually on-going.
Do retaining walls need to be drained?
The process of making sure that a retaining wall drains properly is relatively simple, but it is not very flexible. Although there are exceptions, most retaining walls require gravel backfill, soil compaction, pipe or toe drains, and weep holes. Together, these four features will provide adequate drainage for most designs.
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.
