Dry stone walls - a resource worth the effort

The art of dry stone wall-building is declining on farms around the country. Dry stone walls are those built in the absence of mortar or cement. They are an integral part of our countryside dotted around every corner of Ireland.

Recently, I met Sunny Wieler, chair of the Dry Stone Wall Association of Ireland (DSWAI) and Nick Aitken, Scottish mastercraftsman of DSWA UK. They said that Irish dry stone walls date back to the Neolithic period (3000 BC). The Céide Fields in Co Mayo are the oldest known field systems in the world. These dry stone walls are over 5,000 years old.

Dry stone walls were built for the same reason wire fences are erected today – they create a stock-proof boundary between neighbouring farms.

Walls were also constructed to aid the agricultural revolution in the 16th and 17th centuries. In that period, English planters introduced modern farming practices which required the division of common land to increase agricultural productivity on their new holdings. From that time until the famine ending in 1852, the availability of cheap labour made stone wall building an easy choice for landlords. In some cases, labourers were offered up to five years’ free rent for a small holding if they agreed to help build dry stone walls for their landlord.

Dry stone walls are not just an historic feature on farms that should be looked after for the sake of looking after, according to Sunny and Nick. “If you are fortunate enough to have stone walls on your farm and you have the ability and motivation to keep them maintained, you will save money because you won’t have to erect expensive fencing,” explains Nick.

He says that well maintained stone walls provide shelter for livestock, as well as smaller animals such as mice, rabbits, snails and birds. The shelter a wall can provide can be up to 20 times its height across a field, according to Nick. He says that in exposed areas, it is apparent that grass starts growing at the base of stone walls first in springtime because of the shelter they provide.

Maintenance of stone walls is a Tier 3 action for Glas.

How to maintain a wall

“Not letting breaches get out of hand is one of the main ways you will keep your walls intact,” Sunny advises. He says that if you spend a couple of hours a week or take two to three days out in the year to fix up sections of walls that have fallen, it will cover a lot. If too many breaches start appearing in walls, it becomes harder to maintain and they will only get worse.

Sunny has noticed that ivy is becoming a problem with dry stone walls.

If allowed to, ivy roots grow deep into the centre of the wall and, with time, they get bigger, displacing the stones and causing the wall to fall.

If ivy is already established in a wall, there is little point trying to kill it with spray. This is because the roots will already be too big and if you successfully kill the plant when the roots rot away, the resettling will cause the stones to move and fall.

Sunny says if at all possible don’t let ivy get established in the wall and try and eradicate any signs of young ivy taking hold before it becomes an issue.

Wild trees can also be detrimental to a wall. They should be cut away or moved somewhere else because as they become bigger they will knock the wall eventually. A mature tree adjacent to a wall can be accounted for by putting a break in the wall and erecting a fence to block the gap left.

Sunny says that you could also just acknowledge the tree may from time to time knock the wall and be prepared to rebuild it.

When repairing a dry stone wall, Sunny advises not to add mortar.

“If you are fixing the top of a wall and you add mortar, you will run into problems. The base of the wall with no mortar can move slightly as it naturally settles but because mortar was added to the top this section becomes solid and the two will eventually separate.”

Double walls should not be packed in the centre with sand or rubble. Small rounded stones used in the centre of a wall are the equivalent of building on ball bearings and will cause slippages. Crushed, sharp, angular stones are best.

A single strand of mains fence wire along a wall will do a lot to protect it from cattle scratching.

While there are many different types of walls on Irish farms, here are some of the most common types:

1. Double stone wall: Very strong and well-built with two faces of stone and an inner core of smaller stones.

2. Consumption wall: Also a double-sided structure, it serves a double purpose of absorbing stones cleared from a field and making a boundary.

3. Stone-faced: A wall usually built in front of or against a clay bank.

4. Single boulder: Walls comprise predominantly large boulders around which smaller stones are placed.

The DSWAI is a non-profit organisation committed to promoting a greater awareness and appreciation of the craft of building with dry stone in Ireland. The association organises and runs a number of annual dry stone walling events and festivals across the country. It also organises courses for groups interested in learning the art of improving their skills.

For more information, go to the website www.dswai.ie.