Our share is very sandy and prone to erosion. To slow the hill from creeping onto our driveway, and to provide a flat bed for planting we decided to build some permanent stone retaining walls.
The sand makes digging is made easy. The downside is the only stone we have on site is patchy sandstone. It is quite soft and at one time many millions of years ago I am told it was the bottom of the ocean.
Without a suitable building clay available on site and new terraces in need of support. The rocks for the wall would have to be trucked in. We are lucky, we have a good road to the top of the ridge. So everything is down hill. I ordered a full truck of unseen basalt from near where we sometimes work in Corndale. It was a large pile. And I didn't really know what to do with it next. I had ideas and moved 10 – 20 barrow loads around the place but the pile remained massive.
At the same time, at the top of the creek, A friend had been collecting the rocks that occur naturally and abundantly near his home was learning the art and craft of dry wall rock stacking. After doing some wood work he invited me home to see the result. He has built a beautiful wall, and on the strength of that we asked him to do ours.
He begins work at 7:30am and goes with 2 5 minute breaks till 12. Stacking rocks. Every rock is different. Every rock had a face.
Our friend has completed his third half day of dry rockwall stacking. In the final stages aided by Robin who collected rocks trucked them down and sorted them in front of the wall. All together almost 13 tons of basalt moved by hand and wheelbarrow.
When building a dry stone wall it is very important to get the foundations right. They need to be flat and level. The idea is that they are dug deep enough that the bottom rocks don't roll out from below as the earth moves.
Once you have dug the foundation, rocks are then stacked on top of each other with the flattest face looking outwards. Try to fill in all the gaps with smaller rocks. There should also be a slight lean back up the hill, this is called the "batter".
Once the rocks are stacked and secure, back fill in with smaller rocks to assist with drainage behind the wall. Finally cover them with dirt and plant.
The new beds have been created; all the aloe that was removed for digging the footers and laying the stone was replanted. It was then mulched with leave matter collected from the gutters.
Bamboo mulch and topsoil from under the ice cream bean was also collected, it is very rich in nitrogen. Pineapple was planted with purposeful design to stop people walking on top of the drystone wall and fruit production down the drive.
The stone walls are beautiful and durable.
Word of Caution
Lifting rocks can be very hard work on your back, use care and leverage at all times. Back injury can happen quickly and take a long time to recover from.
These walls are dry stacked, children can unwittingly pull the rocks from top of the stack on top of themselves. If you are going to be building a wall somewhere that there might unsupervised children, you must cement the rocks together
for public safety.
There are many crevices for snakes and lizards to live in – we must be very aware of this, especially at night.