Stone in Wales

by Thom Evans

Something I often hear is that Wales is a country full of hidden gems; I was born and raised in Cardigan Bay, and still live and work there as a stonemason, and cannot argue with this description. I can honestly say that rarely do a few months pass without me stumbling upon a little-known historic building full of delightfully untouched charm. However during my Fellowship year I am coming to realise it may not just be the buildings themselves whose fantastic value is underappreciated but also the people who serve them.
I began the third block of the Fellowship (a time of study away from the other Fellows to pursue our individual interests) by meeting with Dr Tim Palmer a retired senior lecturer at Aberystwyth University whose current charges include being a consultant in Architectural Geology, ex-secretary of the Welsh Stone Forum and enthusiast/font of knowledge on all things stone. The extent of the knowledge Tim was able to impart is far too large to do justice in this blog but I would like to concentrate on one revelation that has caused me to re-evaluate my thinking.

Strata Florida

Strata Florida

Many surviving medieval buildings, whether fortified or ecclesiastical, along the south and west coast of Wales (as well as the east coast of Ireland) appear to contain a certain amount of Jurassic limestone that to the untrained eye could be described as Bath stone. I have encountered this stone, often used for carved detailing, and it had left me somewhat perplexed. Whilst I was often able to discount it as being Bath stone, I had regularly considered it to be Doulting- a hardier more crystalline limestone from Somerset still used today. I often questioned whether this out of place limestone was contemporary to the original medieval fabric, as it appeared not to have weathered as much as one might expect after the ravages of time in excess of 600 years. I suppose, also, I associated the widespread use of the Jurassic limestone in Wales with the Georgian and Victorian era and wondered whether these apparent anachronisms were interventions at this stage. The work of Tim and the Welsh Stone Forum has however been able to settle this little riddle for me.
They have identified this esoteric stone as being Dundry. A non-oolitic Jurassic limestone quarried from Dundry-Hill, just south of Bristol. Whilst it shares many similarities with Doulting such as its age and non-oolitic formation it appears to be significantly more durable. The geological reason for this is explained in detail by Dr Palmer in various papers, but in simple terms the sea lilies whose decaying matter make up the sediment of this stone are Echinoderms and define the dense granular quality of the stone.

Strata Florida

Strata Florida

It is believed that quarrying for Dundry had reached natural conclusion around 1540 when the supply of the best quality beds was exhausted, although a brief revival between 1850-1910 yielded some inferior quality stone. As well as being used extensively for external masonry it was used for numerous fonts, which were often carved in a generic style and shipped across the south west.
So it is easy to understand why this durable freestone which was close to the river Avon, and therefore the Channel, coastline and trade routes achieved ubiquity in its heyday and can still be found now at sites such as Llandaff Cathedral, Chepstow and Newport castles, round to the Bishops Palace in St David’s and as far north as Strata Florida and Aberystwyth Castle. The extensive research and investigation that Dr Palmer and his colleagues at the Welsh Stone Forum have undertaken to highlight the importance of Dundry to medieval masonry should be lauded.

Strata Florida

Strata Florida

The Fellowship has really made me realise that conservation is a collaborative effort. Whether it’s the communities that campaign for funding to protect their beloved landmark, the volunteers that brave the elements to maintain their churches, or the enthusiasts who help us better understand the materials we use.  Many people work away at their own personal interest or profession and rarely get the recognition they deserve. Without them the work we practitioners carry out on site lacks cohesion, and we should be thankful.

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Building Limes Forum

By Declan Cahill
Earlier this year I wrote a blog post on the wonders of lime which outlined a period on the Scholarship where we were beginning to understand the historic use of lime. Since writing that post, we have travelled across most of the UK and met a wide range of people who are involved in the repair and conservation of historic buildings. On saying our thanks and goodbyes, a common question was repeated: “Are you attending the Building Limes Forum in September?” As the conference has now become a well-integrated part of the Fellows’ and Scholars’ programme we were pleased to hear that we would get the chance to catch up with so many people we have met along the way.

BLF Delegates at St. Georges Hall

BLF Delegates at St. Georges Hall

The Building Limes Forum (BLF) is held annually in September and brings together a variety of people from across the UK and further afield for a three day conference on the use of lime in it’s different variations. The conference was held in Liverpool this year and included a programme of presentations, demonstrations and site visits, as well as the annual general meeting of the BLF. I was particularly interested in two topics that were discussed throughout the presentations and demonstrations: hot lime and how our use of naturally hydraulic limes needs to be questioned.

The conference was opened by Stafford Holmes, who presented a talk on “The Delight of Diversity”, giving everyone a reminder of the different geological limestone strata across the UK, and how both earth and lime have played an integral part in the construction of our historic buildings. The first talk on hot lime was given by Roger Curtis, technical research manager at Historic Environment Scotland (HES). He gave an insight into the research being lead by HES into hot lime mortars. I think it is important here to include Roger’s definition of hot lime in their research, that is “quicklime, being mixed on site with aggregates, often gauged. Using a traditional additive (or pozzolan) where necessary, using the material warm, cool or mature and for building, pointing or harling purposes.” Roger gave an overview of the past and current research being undertaken and the four studies that are due to be published in Spring 2017, these being:

Historic Examples of Hot Lime – Tom Addyman
Recent Examples – Craig Frew and Bill Revie
Historic text Extraction – Nigel Copsey
Consideration in the specification of Hot Mixed Mortars – Ros Artis

There is also going to be a database set up for the analysis of lime mortars. This was fully introduced by Anne Schmidt later in the conference. Roger also highlighted that there will be a hot mixed lime mortars seminar in December 2016

Triona mixing lime mortars at Duart Castle

Triona mixing lime mortars at Duart Castle

Roger’s talk lead nicely into a presentation by Nigel Copsey on his research of old texts on lime mortars. His research has highlighted how earth and lime have historically been used in tandem with one another, and how historically mortars would be mixed hot, most commonly using the common or ordinary method of mixing. Roger’s analysis has covered the continent and has included texts from France and Spain that had never previously been translated.

On the Saturday, the conference covered current research into hot lime by Alison Henry of Historic England and the development of mixes for exposed historic buildings by Lucie Fusade at the University of Bath. Cristiano Figueiredo, also of the University of Bath, presented his analysis on how fit for purpose BS – 459-1:2015 is in a conservation context. Sarah Scammel, another speaker from University of Bath, presented her research into the impact of calcite aggregates on the properties of air lime mortars. All of the talks were deeply insightful but have pointed towards how we are under-using quicklime and overusing natural hydraulic limes without really understanding their strengths and properties, and what boundaries the British Standard gives. This research will hopefully further our understanding of lime mortars in their different states and how they act with historic building fabric.

Mixing quicklime using the common or ordinary method

Mixing quicklime using the common or ordinary method

Sunday morning of the conference gave an overview of the various activities of building limes forums around the globe, as well as introducing next years location for the conference, Trondheim Cathedral, Norway between 7-10 September 2017.

The presentations of the conference were closed by David Wiggins, a structural engineer who has researched into lime mortar and sacrificial weathering. David covered the primary decay drivers of lime mortar, frost attack and salt crystallisation, and how the pointing mortar is a functioning aspect of solid masonry construction, actively removing moisture and salts from the wall. Crucial to the pointing mortar’s function is the free lime content that makes the mortars sacrificial. This is something that natural hydraulic limes do not have but a hot mix produces a mortar with a high free lime content.

The conference was a great weekend to learn about the current research and practise that is ongoing and being applied in the effort to repair and conserve our historic buildings. On behalf of the Scholars and Fellows, I would like to thank the Rathbone Foundation for funding the bursary that allowed us to attend the conference and hope that they will continue to support the Scholarship and Fellowship programmes in the future.

More information about the BLF, the 2017 conference and the upcoming Hot Mixed Lime Mortars Seminar & Workshop on 20 October.

Building conservation in Ireland – an Irish Scholar’s perspective

By Triona Byrne

For two countries so close to each other geographically, Ireland and England have very different attitudes to building conservation. We spent two weeks in Ireland recently as part of the Scholarship, and after living in the UK for 6 months, it was eye-opening to see the contrast in built heritage first-hand, and explore the socio-economic reasons that have led to this.

There are myriad explanations for the obvious contrast, not least that the two countries have had mightily different histories – while England has a history of colonisation, Ireland’s past is brimming with invasions and conflict, up until very recently. Economic reasons also play a huge role. Ireland’s economic cycles tend to fluctuate wildly, with drastic cycles of ‘boom and bust’, whereas Britain’s economy has smaller cycles of recession and prosperity. This has a huge impact on the construction industry and the finance available for conservation projects, which also impacts the lure of construction or an apprenticeship/trade as an attractive career path for young people.

Ireland’s building stock includes several structures surviving from prehistoric times – places like Newgrange, a stone age passage tomb, along with many ring forts, dolmens and burial tombs. However these are not as easy to spot as the early medieval round tower, a common sight on the skyline. Although these are not uniquely Irish, a vast number were built around the country from 500 to 700 AD when Ireland was made up of many monastic settlements. Ireland became known as ‘The Land of Saints and Scholars’ due to the flourishing arts and learning of this time, when the rest of Europe was struggling through the Dark Ages. The round towers built at this time were defensive structures, with tiny windows and doorways several metres above the ground, accessed by a retractable rope ladder. Irish round towers are unique in that they have a stone cap, unlike similar round towers built elsewhere in Europe at this time.

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Irish round tower

More common again are ruined structures from the time of Norman and Anglo-Norman invasions, dotted around the countryside. The tower house, the ubiquitous building of this era, was a tall, defensive, stone structure, designed to keep out invaders and provide a good vantage point around the surrounding land. These structures had thick walls, narrow windows (or none at all) and defensive features such as machicolations. These were clearly not ideal living conditions, and so it is not surprising that they were abandoned and let fall to ruin as the Middle Ages drew to a close. However it is interesting to contrast the buildings of this time with those being built in England, where a typical village was comprised of a church, a manor house and timber framed cottages. This village structure was not possible in Ireland, where attacks and invasions were a regular occurrence and a strong defensive building was the optimal home. Peasants of this time lived in small mud huts with a roof of organic matter, none of which survive to this day.

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Ruins of an Irish tower

Between the 12th and the 20th century, the Irish and English fought bitterly for control over Ireland. During this time, the English were generally the stronger side and under their reign, much of Ireland’s culture was suppressed, including the Irish language, traditions and religion. This influenced the building of churches – the Penal Laws stated that “when allowed, new Catholic Churches were to built of wood, not stone, and away from main roads”. Hence the majority of Catholic churches in Ireland today were built in Victorian times.

Probably the most famous Irish building is the traditional Irish cottage. These cottages were built by and for farming families, usually with a stone plinth, earth/cob walls and thatched roofs. Windows were very small, due to the cost of glass (particularly while there was a window tax) and the cottages were one-room deep. This one-room depth was most likely due to the length of timbers available to form the typically A-framed roof.

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A sketch of a thatched cottage near Portlaoise

There were predominantly two types of cottage layout – one where the front door opened directly into a parlour (where the hearth was located) and with bedrooms at either end of the house. The second type had a front door opening in to a small lobby, which was created by a jamb wall standing perpendicular to the hearth. Some jamb walls had a “spy window” that allowed a person sitting at the hearth to see anyone entering the house.

typical-cottage-layouts_triona-byrne

Typical cottage layouts

For me, these buildings define the Irish countryside and its history. They are part of our heritage and represent the industrious farming people who built them. Unfortunately, my views do not seem to be shared by the mainstream Irish public. The majority of these cottages are being left to fall into ruin.

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Ruined cottage

As people today generally want houses with large, open-plan spaces and modern conveniences, they abandon the humble cottage and build new, contemporary buildings on the same plot of land. This results in the high number of ruined cottages that are all over the countryside. This is a sad state of affairs, and is in contrast to the UK where old buildings will usually be adapted for modern use. However the British approach can also be to the detriment of the building, as original walls are ripped out to create “bright, open living spaces”, which historic buildings are not famous for, and inappropriate materials are used. Neither the British or Irish approach is ideal, and it should be applauded when an old building is accepted for what it is and carefully conserved using traditional methods. We saw an excellent example of this in Stansfield, Suffolk recently where we spent a day with Bill Sargent limewashing an old thatched wattle-and-daub cottage that is being sympathetically repaired.

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Rose Cottage, Stansfield, Suffolk

Since Ireland achieved independence nearly 100 years ago (excluding Northern Ireland), Irish people have taken strides to distance themselves from the poverty and oppression that maintained a stronghold on the country for so long. This sadly includes many of the beautiful buildings that were built by British landlords and landowners from the 17th to the 19th century, many of which were destroyed or else let fall to ruin. It also includes the humble cottages and farm buildings that are a reminder of the poverty of the past. Ireland’s lack of a large public funding body for built heritage like the Heritage Lottery Fund in the UK, and organisations like the National Trust and the SPAB, all contribute to this lack of appreciation for building conservation. However, I believe the attitude of the general public is slowly changing and Irish people are beginning to realise that our rich built heritage is a valuable and unique asset that must be protected. I am hopeful that the philosophies of the SPAB can spread to Ireland and that there can be a shift in the public perception of our past and the beautiful buildings that connect us to it.

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Lismore Castle in Ireland where the Scholars stayed for a week