Dry-stone walling

With friend Allan visiting, I wanted to get started on our project to build a new retaining wall in the garden. After a week of effort, both of us have a renewed respect for the wall builders of old!

The garden consists of three main terraces below road level. The upper two are separated by a nice granite retaining wall that probably dates back to when this land was first cultivated. The lower two terraces are simply separated by an earth bank, with a row of vines extending along part of it. We thought it would be nice to add a new retaining wall along the centre section, where there are no grapes. This would allow us to level the lowest terrace, which we plan to leave as natural meadow, while also backfilling the upper terrace by 20cm or so to give deeper topsoil (for some of our Japanese vegetables). Fortunately, there is a large pile of granite resulting from the building work (though I'm not quite sure where so many stones came from...) so we are not short of material.

The first problem to work out was how to move the stones across the top terrace, over the retaining wall, and into position for the new wall. Having decided on a length of about 4m that would comprise the Phase I work, we moved the foundation layer stones down in a wheelbarrow. Some were quite heavy, but by tilting the wheelbarrow on its side and rolling them in, we were able to get them into place.

The foundation layer is complete, and infill material is ready in the wheelbarrow.

We then chose some larger stones for the second layer, and realised they were too large even for the wheelbarrow. We borrowed a low four-wheeled trolley from the neighbour and laid down planks across the terrace. With this arrangement, we were able to move quite large stones -- though getting them onto the trolley required some thought (and some good levers). Keeping the trolley on track was also not easy; the consequencies of going off the boards into soft earth were sometimes messy!

One of the larger stones we've managed to move so far.

We've tried to avoid shaping the stones as much as possible, but occasionally it has seemed expedient to get to grips with the hammer and chisel.

In the photo below, Allan is working to fit the large stone (shown above on the trolley) into place in the second layer.

After a few days, we'd picked up a few good techniques for moving stones. Levers are our friends! But rolling (particularly over planks) also works well. It is surprising how easy it is to rotate a very heavy stone that is lying on a plank. A stone or wood block makes an even easier pivot point.

This stone just about moved itself into position once we reached the edge of the earth bank.

Here's the large stone (seen above on the trolley) in position. The second layer begins to take shape!

We estimated that this one probably weighs 250-300 kg. Here it is sitting on the edge of the retaining wall between the first and second terraces; the wall is about a metre high.

Almost certainly the biggest stone we've moved to date, it didn't go over the wall very cleanly. In fact, it took the trolley with it...

This is where we learnt to respect the wall builders of yesteryear! In this area, there are countless granite walls built to form terraces on steep hillsides. They range from a metre or so high up to monster structures, sometimes 3-4 metres in height. Some of the stones used must weigh several tonnes. Having moved some large stones, we have some ideas about how it might have been done, but the effort involved (just to create a terrace for a row of vines and a few potatoes) still defies imagination.

Here Meg and I take a break on the completed second layer. We now have to put a final capping layer on top. Unfortunately, the stones we like the look of are even heavier than the ones we've moved so far, and we feel that heavier equipment is needed. Tomorrow we are off in search of a suitable winch and pulleys...