Occasionally walls are built too low through poor workmanship or a mistaken effort to save time and money, or the wall’s purpose may have changed, for example from fencing cattle to sheep, requiring it to be higher. The best solution is to remove the topstones and add more courses, but the wall may be too narrow at its top height to allow this, while maintaining the correct batter. If the coping is of locked top construction, and you have sufficient topstones available, you might be able to simply add another coping to bring the wall up about 1′ (300mm).
Walls with fences are a compromise solution, and are not usually particularly attractive. The fence is also likely to have a shorter life than the wall, and is not easy to replace. Where a high barrier or windbreak is needed with only a limited supply of stone available, an alternative solution may be to build a stone faced bank with a hedge planted on top. For stock control purposes, a separate fence alongside, possibly of temporary electric fencing, may be the easiest solution, though this will not encourage repair and maintenance of the wall.
Post and wire fencing
To make a wall stock proof, you can increase the height by erecting a ‘flying’ fence on 7′ (2.1m) poles, placed about 15′ (4.6m) apart and leaning against the wall, with two strands of barbed wire stapled to the posts above the wall top. Larch thinnings or coppice poles will do for the short term. Dig or knock the poles in a short way. In rocky ground where the posts can only be driven in a few inches, set the posts alternately on opposite sides of the wall to make them more secure.
A more durable solution is to wire the posts to the wall. With most walls this can only be done if the wires are put in place as the wall is rebuilt, although with single thickness walls it may be possible to thread the wires through the standing wall. This technique is also necessary if the fence follows the inside curve of a wall, where the tension of the wire would pull the posts away from the wall.
At a suitable height, place a length of wire sufficient to go across the wall, around the post and back again, leaving enough to twist together over a wooden batten. Don’t sit stone directly on the wire or you will trap the wire. On completion of the wall, push a post down through each loop and into the ground, and then use fencing pliers to tighten the wires over the batten.
This can be used to extend a 5-6′ (1.5-1.8m) wall the extra 1-2′ (300-600mm) necessary for fencing deer. Always bring the stonework up to a uniform level before adding any wire fencing.
Occasionally, lower walls of about 3’3″ (1m) height have a ‘flying’ fence of sheep or stock netting. Either C8/80/15 (80cm/31″ high) or C6/60/15 (60cm/24″ high) netting is used. The former is usually set with the bottom wire level with the base of the topstones, and the latter set only slightly overlapping the topstones. A strand of barbed wire 2-4″ (50-100mm) below the netting will block the gap, caused by the thickness of the post, between the netting and the wall. This type of fencing looks unattractive, but does make a low wall proof against sheep from both sides.
The fence posts can be thinner and set further apart than for a standard stock fence, as the fence does not come under the same pressure as a fence at ground level. Posts of 7′ (2.1m) height and 2-3″ (50-75mm) top diameter are suitable, set at 10-12′ (3-3.6m) intervals, with every third or fourth post tied back across the wall as described above.
An interesting variation found at Lough Rigg Terrace, Grasmere, in the Lake District, is a wall with throughstones which project every 6′ (1.8m) on the stock side, and are drilled to take wooden posts. The holes in the upper throughs are about 4-6″ (100-150mm) diameter so a post can be dropped through, with the holes in the lower throughs smaller, so the point of the post wedges into them. Some of the posts are wedged into the lower throughs with small slivers of stone. The posts are simple to replace when necessary.
Occasionally you will find a wall with wooden posts built into the top layers. This is not recommended, as the posts will rot long before the wall should need rebuilding, and trying to replace them will inevitably destabilise the wall.
A very simple method of keeping stock from jumping a wall is to fix a strand of barbed wire along the top, secured every 15′ (4.5m) by a loop of wire around a block of stone about 10″ (250mm) square, placed on top of the coping.
Steel bars
In areas where suitable stone was available, the traditional method of additional stock proofing was to fit large blocks at regular intervals in the coping, into which iron or steel bars were leaded.
A similar but more troublesome method was to set the bars into the wall itself, as is often seen in road and rail-side walls in Scotland. Flat steel standards 2’6″-3′ (760-900mm) were used, drilled to take one or two strands of wire, with the top strand about 1’6″ (450mm) above the top of the coping. The standards can be mortared into the wall, or fixed with lead or glue to holes drilled in the throughstones or coverband. In either case, start by installing the two end posts. Once these are secured at the correct height, run a guideline between them for positioning the intermediate posts.
When using mortar, the standards can be cut and bent to a T shape to give a more secure fixing. Position and temporarily wedge the standards before building up the wall around them.
When repairing a fence with standards, if you find that the wire is still good, but that one or two standards are bent or broken, you can replace them without cutting the wire by sawing slits in the replacement standards.
Slates
In slate districts one sometimes sees walls where some of the slate top stones are taller than the others, and are drilled to take fence wires. Such slates must be very secure, and should be spaced fairly closely, about every 4′ (1.2m).
A similar technique uses slate standards set into the body of the wall. These normally project about 18-24″ (450-600mm), with holes drilled for two or three strands of wire. Their length varies considerably from one wall to another, with some as long as 5-6′ (1.5-1.8m), although around 4′ (1.2m) is the norm. They should be set at least 12″ (300mm) into the body of the wall, with 24″ (600mm) preferable.
The procedure for building is as follows:
- Level the wall to the planned height for the base of the slate.
- Build the next layer, leaving enough space between the face stones for the slate to stand wide end down. Place the hearting, leaving a gap for the slate.
- Set the slate in position, and then one person should hold it vertically, while another person wedges it tightly with hearting.
Use half or three-quarter throughs, two each side of the slate, to hold it firmly in position. It’s a good idea to select these stones before you start building. Check that the slate is vertical.
If the slate is not quite secure, temporarily place blocky stones alongside it while you continue the rest of the layer.- As you build up, place as many half or three quarter throughs as possible alongside each slate, and make sure the hearting is jammed in really tightly against it. The slates must be very secure, as any movement is likely to destabilise the wall in the long term.
- Some stones will have to be ‘traced’ alongside the slates, and should be tied with half or three-quarter throughs above.
- Triangular stones can also be used at intervals, although the stone to stone contact is poor.
Height and line
In common with other posts set in walls, care must be taken to get the holes aligned so that the wire runs straight or at an even gradient. This not only improves the appearance of the wire fence, but is important structurally. If one slate or post is too low, the wire will act to lift and loosen it. Conversely, a post that is too high will cause the wire to exert a force on the adjacent posts.
Use the longest slates at each end or at changes of direction or gradient, as these will take more strain than other slates. When using metal posts, larger posts may be needed for the strainers.
The general procedure is to work on a section of about five or six slates or posts. Carefully position the posts at each end of the section, so that the holes for the wires are at the correct height, and the posts are vertical. Run a line between the tops of the slates or posts, tightening it with pins or stones.
Set each intermediate slate or post so that the top just brushes the line.
Further details on the use of strainer posts and all other aspects of fencing are given in Fencing.
Rails
The use of rails for additional stock-proofing of walls is not common, but interesting examples are found in parts of Scotland, including the Aviemore area. The ‘Inshriach Dyke’ consists of a low coursed wall of granite with throughs and coverband of mica-schist. The topstones are granite, with long slabs of mica-schist set at 6′ (1.8m) intervals, which are drilled to take timber poles of 3-4″ (75-100mm) diameter.
Other variations have the extended topstones notched to take the rails, rather than having holes, and the extended stones sit on the coverband, instead of being built into the wall. These examples probably pre-date the use of wire, as later walls have extended stones drilled to take fencing wire.
