Finishing Material For An Allan Block Retaining Wall

Once the retaining wall is built, finishing touches can be done behind and in front of the retaining wall.

Finishes include things like gravel, top soil, mulch, plants, lighting, grass, handrails, fences and much more.

While these finishes add to the look of a retaining wall, they serve other purposes as well.

In Front of the Retaining Wall

When materials like grass, gravel or top soil are placed in front of the wall, they add pressure, stopping the heavy retaining wall from sliding forward.

Finish materials should bury at least half, if not the whole block on the bottom of the wall. As an example, if 4” of top soil is needed, 6” actually has to be brought in and compacted. Once this is done you are left with the 4” needed to cover that block.

For a material like mulch, at least twice what is needed will need to be put in since it compacts so well.

Behind the Retaining Wall

While some people choose to have mulch or soil behind a wall, free draining material (gravel) is a great choice to keep any water from getting behind the wall.

Whatever material is placed behind the wall should be level with the cap since we want water to run over the cap and in front of the wall, not get trapped behind it.

Something to be aware of is if any irrigation is being done behind the wall it will be adding extra water to the area, and there is a risk of the wall overturning due to the weight of the soil behind it.

This is why having a structural design for your retaining wall is important, as extra precautions such as putting in drainage pipe or gravel behind the wall will prevent this.

Other Add Ons

Fences

Fences add privacy to your backyard and can be placed on or behind a retaining wall. It’s important to note that if a fence is being placed near or on the wall the holes for the fence or sono tube ( a tube that the fence posts go in)  should be dug during the building of the retaining wall. If a fence is installed closer than 3 feet from a retaining wall and has not been planned for you risk the fence applying leverage to the retaining wall and overturning it.

Solid fences apply more pressure to a retaining wall, while fences that allow wind to go throughout them, like chain link, apply far less pressure.

Handrails  

For retaining walls higher than 2 ft a handrail may want to be considered so people do not risk getting hurt. While some municipalities require this, it is hardly ever enforced.

Another option to keep people away from the edge of a retaining wall could be installing hedges or plants if a handrail is not required.

Plants/Trees

Any trees that are being put near a retaining wall run the risk of having their roots damage the wall. It is recommended that the canopy of any trees or deep-rooted plants are at least 4 feet away from a wall. If this is not done roots will travel under the wall and “heave” up the retaining wall.

Lights

Landscape lighting is an extra finish that really highlights the look of the wall and adds an extra ambiance to the space in the evening. Lights can be placed under the retaining wall cap, or in stairs and around the retaining wall.

The possibilities of what finishing touches that can be done to your wall are endless.

While the retaining wall itself is the main focus, adding things like a water feature, fire pit area or raised planters to your retaining wall project really elevates your walls look and can take it from a great looking wall and taking it to the next level.