How to Build a Concrete Block Retaining Wall | 11 Step By Step Guide

Building a retaining wall is an exciting project, especially for the DIY creator. Slopes on a retaining wall trigger a big challenge when building any landscaping projects. Similarly, soil condition also matters a lot as soil weighs over one ton per cubic meter. While building any retaining wall, you must make it strong. Before building, you must know how to build a concrete block retaining wall? Now I will explain to you how you can build a strong wall with concrete blocks.

There are many kinds of retaining walls, but concrete blocks for retaining wall is the best solution. Some kinds are down here:

  • Wood timbers Cinder blocks
  • Concrete blocks: These are the best solution for block retaining wall. Concrete blocks are heavy; due to this characteristic, it bays the soil with their weight.

How to Build a Concrete Block Retaining Wall: Tools You Need

For building a Concrete Block Retaining Wall, it is obvious you will need some tools. We have mentioned the tools below. If you do not have any of them, you can get them from the provided boxes and links. We have picked the best items for you. 

Wheel Borrow

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Gorilla Carts GOR4PS Poly Garden Dump Cart with...
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Gorilla Carts GOR4PS Poly Garden Dump Cart with...
  • Patented quick-release dump feature makes unloading quick and easy
  • New frame design reduces assembly time while offering improved maneuverability and ground clearance
  • Durable 38.7-inch x 20-inch rust-proof poly bed and 10-inch pneumatic tires

Shovel

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OAKVUE Survival Shovel Multitool with Tactical...
750 Reviews
OAKVUE Survival Shovel Multitool with Tactical...
  • PORTABLE AND LIGHTWEIGHT: The OAKVUE camping shovel is a multifunctional tool designed for those of you who love outdoor adventures. Moving with a heavy shovel will make you tired and uncomfortable. That's the reason why we made lightweight shovel which is only 2.5 pounds.
  • STRONG: This survival shovel is constructed with 3CR13 stainless steel. That is durable and can withstand harsh conditions. The mix of chromium and carbon is ultra-strong and rust-resistant. The extension bars are made with aluminum alloy that makes it more lightweight.
  • PRACTICAL AND VERSATILE: Use this portable shovel when camping, hiking, or going on off-road adventures. The folding shovel has an adjustable handle length from 17.4 to 35.8 inches. This compact shovel head has an adjustable angle and can be used as a hook, hoe, or shovel.

3lb Hammer

Estwing MRF3LB Sure Strike 3Ib Fiberglass Drilling...
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Estwing MRF3LB Sure Strike 3Ib Fiberglass Drilling...
  • FORGED STEEL HEAD – Maximum strength and durability for a lifetime of hard work
  • BALANCE AND TEMPER – The most durable, longest lasting striking tools available
  • HEAVY HITTING HAMMER – Perfectly balanced to deliver powerful blows with an easy swing

Transit

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Johnson Level & Tool 99-006K Self Leveling Rotary...
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Johnson Level & Tool 99-006K Self Leveling Rotary...
  • TURNKEY SOLUTION: The 99-006K self-leveling rotary laser system includes a soft carrying case (laser only), a 13’ grade rod, LED one sided detector, a contractor grade tripod, freestanding target, a drop-ceiling bracket, and laser glasses. Dimensions: 6.61" x 4.96" x 6.69"
  • EXTERIOR RESIDENTIAL: Great for leveling forms and footings, aligning fence posts, grading/excavation, or laying out retaining walls, planting beds, and more. Rotation Speeds: 200, 400, 600 RPM. Laser Wavelength: 635nm±10nm (Red)
  • VERTICAL AND HORIZONTAL USE: Use vertically for laying out walls and floors, or installing metal drywall track. Use horizontally to install wainscoting, drop ceilings, or for leveling cabinets. Interior Range- Up to 200 ft. diameter depending upon light conditions. Exterior Range- Up to 800 ft. diameter with detector (included in 40-6516 and 40-6517)

Concrete blocks

Mini Materials Miniature Cinder Blocks with...
  • Super realistic - made with real cement
  • True 1/12 size - the standard for miniature models
  • Each block measures 1.3" x 0.66" x 0.66"

Sand

2 Pounds Natural Decorative Real Sand - for...
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2 Pounds Natural Decorative Real Sand - for...
  • Natural grain decorative sand.
  • Screened and washed.
  • Suitable for various arts and crafts projects

How to Build a Concrete Block Retaining Wall: Steps

For building a concrete block retaining wall you just have to follow the below mentioned 11 steps;

  • Getting started
  • Level the Ground
  • Lay the Base
  • Set the First block
  • Complete the First base Layer of blocks
  • Set the 2nd layer
  • Cut half blocks
  • Set the half blocks
  • Check each layer for level
  • Check the backside of the wall
  • Backfill behind the wall

Now, let’s jump into the step details.

Step 1: Getting started

  • Place selection: 1st of all, select the place to build a block retaining wall.
  • Take permit: Now take a permit from your local government building authorities to know where you make retaining wall is okay or damage any neighborhood property, then don’t consider that place. Must take permit before starting building wall but a wall lowers then 4 ft not consider to take permit.

Step 2: Level the Ground

  • Measure the position of your retaining wall.
  • Layout the position of your retaining wall where you are going to build the wall
  • Remove soil with the shovel.
  • Now level the area with a shovel where you have to build your retaining wall.
  • If you are working on the hillside, it will need significant excavation to make the ground level.
  • If you are already working on the ground surface, you have to make a trench to level it.
  • By following down table, you will understand the sizes:
Normal SizesLevel of surface
4×8×8Short 2×4
4×8×16Scraping of soil Using a sawing motion to create a level surface
6×8×8 
6×8×16Long 2×4
9×8×8It can be used to check a wide surface to make sure it is level.
9×8×16 
10×8×8 
10×8×16 
12×8×8 
12×8×16 

 Step 3: Lay the Base

  • A retaining wall is most stable when it is built over a porous base.
  • The porous layer will help in level the first layer of blocks. Also, it will help in drainage.
  • Use a long 2×4 to level the surface and make it smooth, and put a 2-inch layer of sand and level it.
How to Build a Concrete Block Retaining Wall

Step 4: Set the First block

  • Start from the end of the wall. Put one block into the porous base layer and press it firmly.
  • Don’t press too hard that it takes out the base layer.
  • Now use a level to level 1st block from side to side and from front to side.
concrete block retaining wall design example

Step 5: Complete the First base Layer of blocks

  • Lay down the next joining block.
  • Again use long 2×4 to check the level of the 2nd block with the 1st block. If you don’t layer it correctly and all layers from down to up are not equal, you will see it will show the difference from the top and never make a strong wall.
  • Put all other blocks in the same way. And must level it with a long 2×4 to level it accurately.
  • Check after each block to make sure blocks are leveled with previous blocks.

Step 6: Set the 2nd layer

  • In the 2nd layer, rows of block installed so that it covers the joining point and cover the half of 2 blocks.
  • In this way, it firmly attaches to the down layer with a running bond.
  • This pattern is considered stronger and more stable than a vertical pattern.
  • Install the entire 2nd layer before cutting blocks in half and filling at the end of the gap and cover it.
how to build a concrete retaining wall

Step 7: Cut half blocks

  • The blocks can be cut in half by using a masonry chisel and hammer.
  • There is already a v-notch groove in blocks, which allows the blocks to divide easily in half.

Method for cutting:

  • Stand the block in the block upright position, the face down, now position the chisel masonry into the groove.
  • By using a hammer, hit the end of the chisel to split it into two pieces.
  • You can use a hand maul or hammer to hit the chisel.
  • You will need several hits to break the block into pieces.
  • One more thing, if your chisel doesn’t have a cushion on end, then when you hit the chisel, it will sound more. To prevent this hearing issue, wear hearing protectors.
how to build a concrete retaining wall

Step 8: Set the half blocks

  • At the end of each alternating layer, put the half block to complete the layer.
  • If there is any rough face on the block, must put it outward so that all straight sides can join firmly into the adjoining soil.

Step 9: Check each layer for level

  • When each row is completing, check the level.
  • If your wall is short, then use 2-4 foot carpenters level.
  • This level will help you in checking 2-3 blocks at a time.
  • If your wall is long, then use a string level; a long string will help you create a reference line as you install each concrete block layer for the retaining wall.
how to build a block wall

Step 10: Check the backside of the wall

  • When you build a retaining wall, you must leave a distance between the wall and the back of the blocks. 
  • When each layer is completed, check the space.
  • You may need to evacuate the excess soil as wall-size increases.
  • You might wonder why this space is necessary. It will provide space for backfilling with porous sand.
how to build a cinder block retaining wall on a slope

Step 11: Backfill behind the wall

  • By using sand or gravel, fill the gaps between the blocks.
  • Now put the porous material in small portions; if you shovel too much porous material at once, the wall will no longer stabilize for a long time.
  • The more compact the backfill, the more stable your wall will be.

How to Build a Concrete Block Retaining Wall: Frequently Asked Questions  

Can I use a cinder block for the retaining wall?

Yes, you can use cinder blocks for the retaining wall. It’s not suitable for longer walls. I only prefer a minimum of 4 feet and a maximum of 6 feet block. If its base is accurately built on, then the whole wall will be straight.

What is the least expensive way to build a retaining wall?

Pine blocks are the least expensive way to build a retaining wall. As you go up on, excellent materials, price increases such as hardwood, railway sleepers, and concrete for retaining wall are the most expensive way to build a retaining wall.

How high can you build a concrete block retaining wall?

Maximum height for building a concrete block retaining wall is 20 feet. These long walls mostly build on the hillside. 

What is the easiest retaining wall to build?

All types are easy to do, but pea gravel is the easiest retaining wall to build. 

Place selection: 1st of all, select the place to build a block retaining wall.

Step-1:

Take permit: Now take a permit from your local government building authorities to know where you make retaining wall is okay or damage any neighborhood property, then don’t consider that place. Must take permit before starting building wall but a wall lowers then 4 ft not consider to take permit.

Step-2:

Level the Ground

Step 3:

Lay the Base

Step 4:

Set the First block:

  • Start from the end of the wall. Put one block into the porous base layer and press it firmly.
  • Don’t press too hard that it takes out the base layer.
  • Now use a level to level 1st block from side to side and from front to side.

Step 5:

Complete the First base Layer of blocks

Step 6:

Set the 2nd layer

Step 7:

Cut half blocks

Step 8:

Set the half blocks

Step 9:

Check each layer for level

Step 10:

Check the backside of the wall

Step 11:

Backfill behind the wall

Should you fill cinder blocks with concrete?

Cinder and concrete can both help each other as if you are using cinder blocks, then concrete will help cinder to strengthen; if you are using concrete blocks, the cinder will do the same work.

Conclusion

Building a retaining wall, concrete blocks are the best option, making the wall stronger for centuries. In the same way, cinder blocks and porous base used as firming agents for concrete blocks. Now I explain to you how to build a concrete block retaining wall. I hope this article will help you in building a strong retaining wall. One thing must remember after each level; you must level it so that it can build a straight wall if you don’t consider this step. As a result, the wall is not more firm and will never cooperate for a longer period.

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