Stone walls at the entrance to our property, completed in the summer of 1993/1994.
Before I start describing this method, I would like to dispose of some hopelessly romantic and ill-founded notions about dry stone walls.
Certainly, dry stone walls are quick and easy to construct, though they soak up a staggering amount of rock for their height and utility.
Constructed properly (which in Australia they rarely are, it is a skilled craft) they are a beautiful thing. But they are never maintenance free.
There is a wonderful poem, Mending Wall by Robert Frost which begins:
Mending Wall
Something there is that doesn't love a wall,
That sends the frozen-ground-swell under it
And spills the upper boulder in the sun,
And make gaps even two can pass abreast.
The work of hunters is another thing:
I have come after them and made repair
Where they have left not one stone on a stone,
But they would have the rabbit out of hiding,
To please the yelping dogs. The gaps I mean,
No one has seen them made or heard them made,
But at spring mending-time we find them there,
I let my neighbor know beyond the hill;
And on a day we meet to walk the line
And set the wall between us once again.
We keep the wall between us as we go.
To each the boulders that have fallen to each.
And some are loaves and some so nearly balls
We have to use a spell to make them balance:
"Stay where you are until our backs are turned!"
We wear our fingers rough with handling them.
Oh, just another kind of outdoor game,
One on a side. It comes to little more:
There were it is we do not need the wall:
He is all pine and I am apple orchard.
My apple trees will never get across
And eat the cones under his pines, I tell him.
He only says, "Good fences make good neighbors."
In Australia in a garden situation, dry stone walls are a magnet for every weed in creation. Ivy, Periwinkle, Privet, Cotoneaster arrive unbidden and take up residence. The local University in Armidale has spent a fortune on trying to eradicate Ivy from their dry stone walls, which move the rocks willy nilly, and the Ivy when killed then shrinks and rots, causing the dry stone walls to collapse further.
Not only that, a good friend and wonderful gardener who built many dry stone walls in a garden near us finally pulled them all down.
He decided that the best description of them was "Tenements for Tiger Snakes"!!!!!!!!
The stone walls I describe here are close to maintenance free. No snake can take up residence, and it is almost impossible for weeds to invade, since there is no sustenance for them. Properly made, these stone walls are something which will greatly increase the market value of a property, and will give joy to the inhabitants, and shelter for plants which would otherwise struggle to survive. Armidale is a difficult place to grow plants, since we get fifty frosts a year, and drought is an ever present threat to the survival of plants. These rock walls offer protection from cold and hot winds, and radiate warmth they have soaked up from the sun during the day, during the frosty nights which follow in winter.
Foundations
The first step is to dig the foundations. I build them very deep, at least six to nine inches. There is more weight in my stone walls than most house foundations have to cope with. Each linear metre of the front walls weighs more than one and a half tons, and the internal walls weigh more than one and a third tons per linear metre. The front walls shown in the photo above had foundations that were more than six inches thick, and with steel mesh reinforcement as shown in the photos to the left. I advise you to use steel mesh reinforcement no matter what the substrate. I dug the pier sections more than nine inches deep, and put extra steel in that part of the trench, and wired all the mesh together. Each of the piers weighs more than one and a third tons. I left an expansion joint in the foundations (near the radio in both photos) and later the wall to minimise the chance of cracking, since in this case the wall "turns the corner".
It is essential that the foundations be dead level from side to side, and for something like the front fence above, that the foundations be dead level from one end to the other. The side to side levelling can be done using a spirit level, but to get the levels from one end of the two sections of rock wall at the front entrance to the far end to be exactly right, I used a long piece of clear plastic tube filled with water, from which all bubbles had been excluded. This worked very well, and it is worth spending a lot of time and effort to get it right all the way along the trench.
If the wall is going to be going uphill or down, make sure that it is a standard steady fall or rise all the way from one end to the other, don't have waves in the foundation, they will be reflected in the top of the wall, and will greatly detract from the finished product. Remember too that although the wall itself can go down or uphill, the piers when finished must be completely vertical, and the tops of the piers must be horizontal, obtained by propping up the formwork temporarily on spacers such as wood shims at one end. This too is essential if you want a good looking result.
In addition, I lined the trenches with strong orange plastic. This had the effect of helping to keep the moisture in the concrete as it set, and also meant that the sides of the trench did not have to be concrete proof, and cut down a little on the amount of concrete needed. The width of the foundations should be at least eight inches wider than the width of the wall, with four inches of foundation showing on each side, both for the wall and the piers at each end of the wall.
The foundations should be poured in one pour, unless you are putting in expansion joints and can break up the work in that way. All foundations were mixed using an electric mixer, sand and gravel pre-mix and cement in a strong, waterproof mix of five of sand and gravel pre-mix to one of cement. Don't use too much water in the mix, it should be as stiff as possible while still being able to pour it into the trench. Good concrete is ruined by too much water.
As you pour, make sure that the steel reinforcing mesh is kept at the right height and doesn't move from the middle of the trench to the sides. Level the concrete from side to side using a wooden screed with a side to side see-saw action, and later a wooden float to get it flat but with a rough surface which keys easily to the mortar. By the time you get to the end of the pour several hours later, the first part will have begun to harden. I scratch my name and the date on the concrete which will be covered by the rock wall, as well as somewhere it can be seen but is not obvious on the margins.
Once you have completed the pour, keep it wet for at least a week. This is easiest to do by spreading plastic over the foundations and putting the hose under the plastic a few times each day. This gives the concrete added strength.
Photo: Don Hitchcock
I was sometimes able to use steel fence posts, called star pickets here, for my vertical posts. Because the ground is so rocky, sometimes it was difficult to get the steel post to be vertical, and often I had to bolt a piece of wood to the steel post, making the edge of the wood vertical, or even to set up a wooden triangular formwork to carry a wooden vertical board in the right position, as can be seen in the photo at left. Be wary of wind when lining up your formwork, with a long section of wall the line can be blown significantly off true. I organised the vertical posts so that the line went along the inside edge of the formwork, and this worked well. You only need to line up one side, the other is automatically lined up by the formwork, and because the two sets of formwork (or their supports) sit on the horizontal surface of the foundations, it is always vertical as well.
Photo: Don Hitchcock
Once the concrete foundations have cured, after a week of keeping them wet, you can pull off the plastic, or in this case old sacking and waste textiles, and you can re-check the vertical posts and put the formwork on the foundations. The structure the children are sitting on is a stock grid, used here to keep stock out, without needing to open and close a gate. You should always complete structures like this before laying any foundations.
Photo: Don Hitchcock
Rock walls facing east have allowed us to be able to grow citrus fruit, which are marginal in this area, since we get fifty frosts a year. They derive shelter from the stone walls, and the stone walls provide a satisfying visual backdrop for the trees. We grow lemons, cumquats and oranges, and even red grapefruit, while a self sown nectarine provides large crops of delicious fruit in season.
Photo: Don Hitchcock
Boysenberries and brambleberries and grapes thrive on the western side of the same wall, completed in 2009.
Photo: Don Hitchcock
The first stone wall, photographs taken in 1980.
The internal stone walls are three feet six inches high and eighteen inches across.
The internal stone wall piers are three feet nine inches high, and are two feet square.
For the front walls, the walls are four feet high, and the piers are four feet three inches high, with the same widths, eighteen inches across, two feet square for the piers. These proportions give a very good and solid looking wall. It is a mistake to make a free standing stone wall like these too thin. If it is well made, it will be strong enough, but it will not look substantial. In addition, you will not need as much skill to build a thick wall as a thin one.
I made my formwork using hardwood wooden planks bolted together, and with pipe which I measured, cut, and threaded. This is a labour intensive process, and if I were to do it again, I would buy some thick waterproof marine ply, and use that for both the sides of the formwork and as a substitute for the pipe, bolting uprights to the middle of each side of the formwork, then using a heavy metal angle bracket without triangulating reinforcement (which I found got in the way when I used them in the curved section formwork) to hold overlapping horizontal pieces of marine ply, drilled to accept bolts and wingnuts, with one slightly higher than the other to account for the thickness of the ply. This method has the advantage that you just drill some extra holes and move the bolts when you want to widen the formwork for the piers. You will need two sets of formwork, so that you can work on both the pier and the wall at the one session. Only one set needs to be able to be widened to the width of the pier.
When using the formwork for the piers, I inserted a short piece of pipe to widen the formwork by six inches, which can be seen in two of the photos above. To get the extra height of the piers, I simply stood the legs of the piers formwork on bricks or wood to get it the three inches higher that I needed.
The basic measurements for the formwork are four feet long by one foot wide. I used tomato stakes as a method of moving the formwork up the stone wall. I attached the stakes with ordinary wood screws. Originally I had sheet metal lining the form work, but eventually took it off when it did nothing useful and got coated with mortar which was difficult to remove. Mortar falls off, it does not need to be removed from raw wood.
It is important to have a method of tightening the formwork. I used a turnbuckle, and constructed the formwork modified from the diagram of what is called the "Modified Magdiel form" in an inspirational book called "Stone Masonry" by Kern, Magers and Penfield, 1976, published by Owner Builder Publications. Although it is out of print, it is still available in used but good condition from booksellers such as Amazon. I read this book over and over until it was dog-eared. I got the principle of finishing the top of a stone wall "effortlessly" from this book. I highly recommend it.
You will also need to make up an end piece for the piers. I used a number of methods, but finally settled on a piece of chip board strengthened with pine off-cuts, and with vertical off cuts on each side, to which I attached G-clamps when I wanted to do the end of the wall.
Photo: Don Hitchcock
To get a good result for the rounded corners I wanted for the front entrance walls, I needed two pairs of heavy steel bars bent to the dimensions I needed. I calculated the radius of each of the turns, worked out how long the bars had to be, and took the plans to a local engineering works. They had no trouble cutting and bending the four bars into perfect arcs for me, and it was not expensive.
I then drilled holes in the bars, and attached thin three ply to the bars, and made up an arch to hold the whole thing together using fence droppers, thin bolts and nuts, and a couple of shelf brackets. It was not worthwhile spending a lot of time and money on this formwork, it was specific to this job only. It held up well, and was perfect for what I wanted.
Photo: Don Hitchcock
The front entry walls and grid are my pièce de résistance. I could only have attempted it after a long apprenticeship of building many uncomplicated straight rock walls. If you are contemplating building rock walls for the first time, I advise you to do the same, and complete a number of smaller projects before tackling something this ambitious. If you get it wrong, it is not easy to undo.
Don't be tempted to plant a foundation destroying tree in the space defined by a construction such as this!
Photo: Don Hitchcock
There were a number of problems to solve, not least that I wanted the entry to be rounded, not a sharp rectangle form, since cars enter it at a reasonable speed. I wanted the stock grid to be generous in width, in marked contrast to most entries to country properties in our area. I first completed the pit for the grid, constructing it from concrete very well strengthened by good quality steel mesh, and using a very strong mix. Large trucks have used it with no ill effects, a tribute to its design and strength.
Photo: Don Hitchcock
I was advised by Les White, a good friend of mine with a lot of experience in building not only grids and other utilitarian farm structures, but also houses, that the grid needed to be above the general level of both sides of the grid, to avoid the pit becoming filled with gravel. This advice was invaluable, and the grid works well.
Photo: Don Hitchcock
Les also advised me to put an expansion joint in each of the walls, both in the foundations and in the rock walls. I was not sure how easy this would be to do, but I followed his advice, and all went well, and most visitors would never know they are there.
The top of the walls are dead level and flat as a tack from side to side and from one end of the two walls to the other. This is a source of great satisfaction to me. It took time and effort to do, but there was nothing inherently difficult in the task, and it improves the project immeasurably.
Photo: Don Hitchcock
A minor detail was the finishing off of the ends of the pipes under the entry from the road. Normally this is done by council workmen, but by this time our road was no longer a main road, and we were the only residents on a cul de sac, so I was allowed to do the whole thing myself, from ordering and laying the pipes, to the fill over them, to the finishing off of the ends of the pipe.
I tackled it with gusto, and decided to finish it off using the same methods I had used for the rock walls. I flatter myself that my treatment is a great deal better than anything else I have seen on council constructed entry ways. They use standard precast concrete, and all of them look the same. I used the formwork for the rounded corners of the walls, and it came up a treat. After building the surrounds of the ends of the pipes, I backfilled with what we call "crusher dust" which is a gravel made of crushed basalt. Fitting for a basalt wall, I thought.
Photo: Don Hitchcock
These images demonstrate the basic method for setting up the pier and straight wall formwork. The pier formwork should be in line with the straight wall formwork, the pier should be two feet by two feet, and the end piece must be square and vertical. You will need two G-clamps on the end piece for the first course, but four are better for subsequent courses.
Mark on both the pier spacer and on the end piece a mark where the brickie's line should go, three inches in from the outside.
You will need a carpenter's square and a spirit level. I used a carpenter's square with one leg two feet long, which was ideal, but even a small carpenter's square works fine.
Photo: Don Hitchcock
In the case of the pier, the end piece will function as an end spacer for one end of the formwork, and often as the middle spacer as well, though have one made up just in case, two feet long. You will still need a spacer for the end which overlaps the thinner formwork, and you will need to take out a generous chunk of the spacer so that it fits over the top of the thinner formwork, but still fits snugly against the pier formwork. This spacer will not need metal hooks or a lap joint, since it sits on the thin set of formwork - except for the final course, when the thin formwork is lower than the pier formwork. A screw in each end works fine instead of a metal hook.
You need to make sure that the end of the thin set of formwork is exactly two feet from the end piece of the pier, and that everything is square in every direction, and that the end piece is vertical, and check again that you have marked the edge of the end piece on the concrete foundations with permanent marker.
Photo: Don Hitchcock
If you have a cement mixer, by all means use it, but you can get by perfectly well with a brickie's hoe, as shown here. It is a broad hoe with big holes in it, which aids in mixing the mortar.
I use a strong mortar of a little less than one bucket of cement to half a bucket of hydrated lime to three full buckets of brickie's loam, which is a sand mix available locally which contains a little extra clay to improve workability. By using just less than a bucket of cement I get two loads of mortar from a twenty kilogram bag of cement. I add one bucket of water to this, but you should work out what amount of water you need by adding it gradually the first time, and keeping a note of how much water you need. If the sand is out in the weather, and it rains, it will contain enough extra moisture to throw your calculations out. As for concrete, too much water spoils mortar. It should be easily workable, but not sloppy.
I mix by slicing down the face of the mixture with the hoe and drawing it to one end of the barrow. I do this three times from alternate ends, then add the water, and it usually takes six goes before the mortar is fully mixed. The advantage of the hoe is that there is less set up and pull down time, and it is a lot cheaper than getting a mixer - though you need one for the foundations anyway unless you get in ready mix concrete.
Adding the right amount, or close to it, of water right at the start makes the mixing much easier and faster.
Photo: Don Hitchcock
The rock walls around the house define the garden area.
Photo: Don Hitchcock
This is one of our favourite sections of the whole property, what we call the corner garden, in the shelter of two rock walls.
It is a place of tranquility and peace, a section of the garden that never fails to heal what ails you. There is a bird bath, a superb grass tree, and a number of rare and endangered native Australian species which have thrived from the moment they were planted.
The white trunked snow gums are far enough away from the walls that they do not endanger the foundations, yet they provide perches for tiny honey eaters who survey the area before darting to the bird bath to drink, as well as daytime cover for tawny frogmouths, the cryptic nightjars which are almost impossible to see when they imitate a dead Eucalypt branch. Then in the evening they head off on silent wings to look for insects and other prey.
Photo: Don Hitchcock
The gardens in front of the rock walls have been planted with native plants, which need little extra water.
Photo: Don Hitchcock
It will take a while, but eventually mosses will colonise the moister areas, and lichens will form, especially on the top horizontal surface of the rock, and on the side away from the sun. I am told you can speed the process up by painting or spraying the rock with milk, but I have never tried that method.
Time works.
Photo: Don Hitchcock