How to Build a Retaining Wall in Front of an Existing Wall

Unstable walls can be secured with a retaining wall.
Unstable walls can be secured with a retaining wall. (Image: Creatas/Creatas/Getty Images)

Walls are built to stay strong over a long period of time, but a changing landscape of harsh weather conditions can cause a wall to weaken. Building a retaining wall in front of an existing wall can help protect the old structure while giving you double the protection. Installing a retaining wall properly is essential; failure to do so can lead to the wall crumbling, which may cause injury. Do not attempt to build a retaining wall that is over 4 feet in height without consulting a contractor or your local building department.

Things You'll Need

  • Shovel
  • Measuring tape
  • Sand
  • Tamper
  • Concrete blocks
  • Retaining pins
  • Rubber mallet
  • Gravel

Video of the Day

Dig a trench that is 1/10 the final height of the retaining wall. Make the trench so it is 12 inches away from the original wall.

Add 1 inch of sand to the trench to level the soil out. Compact the soil with a tamper to prevent settling.

Lay down a layer of concrete blocks into the trench. Set a carpenter's level on top of the blocks to ensure they are level.

Lay a new level of concrete blocks on top of the first layer 3/4-inch back from the front of the first layer. This creates a step look to the wall.

Insert a retaining pin into each concrete block and hammer it into the block below with a rubber mallet.

Pour gravel between the retaining wall and the wall behind it after each layer is set down. Compact the gravel. The gravel allows drainage behind the wall.


Promoted By Zergnet
Is DIY in your DNA? Become part of our maker community.