Stone building: introduction

What is stone building?

Stone building or stonemasonry has existed since humans could first make tools to work stone. Stonemasons work rock into the desired, often geometric shapes, and then use the stones to make structures. Whilst some stone work is done ‘dry’, much stonemasonry involves the use of mortars, and the understanding of the crucial relationship between the mortar and the stone. There are three main aspects to the stonemason’s craft: choosing and shaping the stone; the lime process; and the structural work of building in stone.

Pointing-Kilpeck

Repointing a stone wall with lime mortar.

Stonemasonry in the UK survived to the present day largely thanks to its role in conservation of our architectural and ecclesiastical heritage. In colleges, for example in York and Weymouth, ancient skills have been kept alive long after structural stone building and the use of lime mortars has fallen almost entirely from favour in mainstream construction.

We owe then, the continuing and developing tradition of this craft to the modern concern for Britain’s built heritage. However, stonemasonry also has a role to play in sustainable building for the future, as well as perhaps, in the plans of self-builders in some circumstances.

stone-house

Contemporary stone house.

Most stonemasons these days find work in urban centres, and for big companies that are not specialists in stonemasonry. Outside of this environment, stonemasons need to be adaptable and skilled in more than just building walls in stone. For this introduction, I was lucky enough to talk to Alastair Mcgowan whose work includes restoration, new build and training; he undertakes lime and stone projects, drystone walling and architectural/ecclesiastical restoration and conservation. These are the main different kinds of modern stonemasonry.

What we’re not talking about is ‘slipform’ stonemasonry, which uses natural stone as facing only, on poured concrete walls.

bridge

Various other things, apart from houses, can be built with stone.

What are the benefits of stone building?

The craft of stonemasonry is very different to the industrial approach of the construction industry in which so many bricks laid per hour is the overarching goal. Stonemasonry works with natural materials, and in sympathy with them. Stonemasons talk about the ‘soft principle’ – lime mortar is flexible and the joint is softer than the masonry unit. This gives buildings a resistance and durability that is lost with the use of cement. The flexibility of buildings is a major factor in their ability to survive the test of time; it means that the building can move millimeters without cracking, can settle and shift with the Earth and the people who use it.

Of course, as a craft, stonemasonry is a skill hard won through long study and practice. For those involved in any craft this is clearly an advantage for the people involved. Whilst the phrase to ‘learn a trade’ still has some minimal currency in our society, the understanding of how and why this is an innately good thing for a person has largely been lost – not however amongst those who practice a traditional craft or have acquaintances who do so.

A selection of beautiful old stone cabins

Heritage and traditional skill bursary schemes exist to help the transmission of crafts like stonemasonry.

Stonemasonry creates buildings amenable to long-term repair and maintenance. The creations of stonemasons are built to last for centuries, but they can also be endlessly cared for using the same materials with which they were first built. It is true of course that stonemasonry is time consuming and relatively costly, but the results speak for themselves – rather than buildings that may well be obsolete or unusable within a generation, the works of stonemasons endure.

Stone is the most durable building material, but doesn’t require the energy and pollution involved in the firing of bricks or cement manufacture. Cement mortars and renders should not be used in stone construction, as it sets harder than the stone, which means any moisture in the building will find it easier to escape via the stone than the cement, causing frost and evaporation damage to the stone.

cement-stone

Damage to a stone wall caused by the inappropriate use of cement mortar and render.

What can I do?

Becoming a stonemason is always an option, or at least as long as there is either funding for the heritage skill bursaries or stonemasons willing to train apprentices, but the question I asked Alastair was what the novice might be able to undertake; someone who had perhaps taken a short course and read a good book or two.

If you want to build a stone plinth wall for a bale building or an earth building, then that would be an achievable, as well as a really useful project to undertake. But Alastair’s opinion is that a house would be another matter entirely as a DIY stonemasonry project. The forces at play in a large construction mean that it would always be worth seeking the advice of someone properly trained, and perhaps, even as a self-builder, employing someone to come in and help, or to oversee the work from time to time. When I rebuilt a stone house in France, I drew on the skills of a local man who I employed for a couple of weeks at the start of the project for the most technically challenging part of the job. The house is still standing, although I wish I’d had the money to employ a stonemason throughout the reconstruction of the walls.

Small, stone bothy on the Isle of Lewis, with a wonderful view.

In some places it might actually be easier to get planning permission for a stone building than for any other sort. There are parts of the UK where stone building is the local vernacular, and even places where building or repairing in an appropriate stone is obligatory.

If you buy a stone building of course, then you might as well learn about stonemasonry. You might still need a stonemason to come in to help on more complicated jobs, but it’s always a good idea to understand as much as you can about caring for your own dwelling.

You might buy a pile of stones that was once a house, and be determined to put the place back in the same style. This is one very good way to overcome the problem of sourcing stone. Quarried stone is expensive, and second-hand stone is often hoarded; imported stone is usually pre-finished for specific jobs (and of course for environmental reasons, it’s not a good idea to transport something as heavy as stone over large distances). If you need stone then asking around or talking to local farmers is always a good idea, there are many abandoned quarries and ruins around that might prove to be a good source of material.

pyramids

Stone is the most durable building material, and there are some extremely old stone buildings still around.

A traditional craft like stonemasonry depends upon a highly specialised toolkit, and trying to work stone with inappropriate tools will lead at the very least to disappointment and frustration, and likely to bruised knuckles or worse as well.

A tungsten-bladed pitcher is used to drive a crack through a stone, a steel hammer to hit it. Nylon mallets and tungsten masonry chisels and points are used to shape the raw material for building. Alastair’s tools mostly come from France, and putting the kit together is an expensive undertaking; the pitcher alone costs around £70.

Stones are heavy and tools can hurt. Health and safety has been of serious concern to stonemasons for thousands of years. Goggles and safety boots must be worn, and the art of safe lifting learned. Few of us will ever have to place stones on spires or tall chimneys, let alone work with Medieval cranes or rope-lashed scaffolding, but stonemasonry remains a craft that must be respected. Tendonitis or a splash of lime mortar in the eye are bad enough, but a stone on the foot, arm or leg can be catastrophic.

stone-steps

A flight of steps being constructed with raw stone and no power tools.

Traditional stonemasonry requires a specific mindset. The lime process itself can take anything from a day to weeks depending on the weather, and finding and preparing stone needs a methodical approach. These are not jobs that can be assaulted. Alastair Mcgowan says that even on a cognitive level trying to sort stone for longer than a few hours in a day can be counter-productive.

So, you can’t work with lime when it’s too hot, or when it’s too cold, and stones need to be carefully selected and prepared. The work demands focus, but also patience. It is in essence the antithesis of industrial work.

 

Thanks to Paul Jennings of Lowimpact.org and Alastair McGowan of McGowan Masonry for information.


We'd love to hear your comments, tips and advice on this topic, and if you post a query, we'll try to get a specialist in our network to answer it for you.