Cleaning a stone retaining wall

Retaining walls are meant to be as decorative as they are practical. To maintain their beautiful aspect it is important to clean and wash the stone several times a year. One of the benefits of stone walls are their low maintenance, but low maintenance does not mean no maintenance. Over time the stone will accumulate dirt, moss and grime. But it is extremely simple to clean this off entirely. All you need are the right tools.


  1. Pressure Washer (unless you plan on doing a lot of washing, it is better to rent a good quality washer rather than buying a cheap one)


  1. Kitchen Brush


Thankfully there is little prep needed for cleaning stone retaining walls. Essentially the area just needs to be cleared of any debris and if any vegetation has grown over the side that needs to be pruned or moved before continuing. You don’t want to plaster broken down plant matter over the rocks instead of cleaning them.

Pressure Wash

The fun part is using a massive pressured water stream to blast dirt off the rock wall. If you’ve never used a Pressure Washer in the past, don’t worry it is easier than it looks! Simply read the instructions that come with it to set up the device. Basically all your need is water, petrol (if it’s petrol driven) or a long extension cord if it’s electric. Now for the fun part! Pick an end to start with, and do each rock from top to bottom. It’s important to start from the top, as you don’t want dirt covering recently cleaned rock again! It’s a great cleansing feeling to watch all that dirt run down. Be careful not to spray any grass or dirt. It will go absolutely everywhere if you hit it with anything.

Alternative: Brushing

Now I don’t recommend this over pressure washing, but with the drought in the outback and a growing concern for water conservation some might not feel comfortable using it to clean something for aesthetic purposes. Using a a kitchen brush and some elbow grease is a good alternative, and an amazing workout! As you might expect, it won’t be as thorough a clean unless you also use a steel brush but the goal of using a brush is just to get the worst of the dirt off.

The technique is simple. You pick the end you want to start, I suggest the end you will see more often as effort can sometimes drop off as you get closer to the end. (Manual labor is hard). Then from that end, you choose a rock and meticulously scrub the brush. Remember, your goal is to remove the worst of the dust rather than all of it. If you plan to do this over the course of several days, you may not remember what rock you finished with. I recommend using a small piece of chalk to mark the rocks you have finished.