Below I’ll describe the stages to a simple dry stone wall gap repair I carried out near Lancaster.
Next, you excavate the stone to the base so you can see where to begin. Place the stone just behind in arms reach. You need to inspect the base to see if there is any remedial work to be done. Foundation stones sloping forwards need to be dug out and re-set straight and level.
Once the base is determined to be straight and level, you can start the build. Start with the larger stones at the bottom. The length of the stone should go into, and not along the length of the wall. This aids stability, but is easier said than done, as it’s often easier to create a ‘nice face’ by using the length along the front. The skill is in creating a sound wall, aesthetics is a secondary consideration. As you place the stones, you must be trying to cover the joints or cracks between the stones below. This is integral to the walls longevity. You do not want a seam running more than two stones or courses high. On a random wall like this, you must also look out for diagonal seams as well as vertical.
Inside the wall we place heartings. These are smaller stones to fill the gap between the facing stones either side. Pinning stones are also used to make sure the facing stones don’t wobble. They are shards that are slipped underneath.
Once at knee height you ought to place the through stones. These are large stones, big enough to straddle both sides of the wall. Their purpose is to hold both cheeks together. They should be spaced approx 90cm apart centre to centre. In the photo you can see two that i have put in. I had to use slate, as you can see on the right. There wasn’t another large sandstone available. If the wall is to be over 5ft in height, another level of throughs should be placed, alternated in between the larger ones below.
When near the top, a string line is placed between the copings either side of the gap, at the base of them.
Below you can see the finished wall. The wall is built straight using a string line and the copings are places so as to be tight against each other. The coping ought to ‘nip’ the top stones either side of the wall to hold them in place. Over time, the wall will settle and if built correctly, will become tighter and stronger.
