The Winston Churchill Memorial Trust of Australia. Report by - Maurice Potrzeba Churchill Fellow

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The Winston Churchill Memorial Trust of Australia

Report by - Maurice Potrzeba - 2010 Churchill Fellow

To study Lime and Historic Mortar, Gauged Arches and Niche Construction

I understand that the Churchill Trust may publish this Report, either in hard copy or on the internet or both, and co sent to such publication. I indemnify the Churchill Trust against any loss, costs or damages it may suffer arising out of any claim or proceedings made against the Trust in respect of or arising out of the publication of any Report submitted to the Trust and which the Trust places on a website for access over the internet. I also warrant that my Final Report is original and does not infringe the copyright of any person, or contain anything which is, or the incorporation of which into the Final Report is, actionable for defamation, a breach of any privacy law or obligation, breach of confidence, contempt of court, passing-off or contravention of any other private right or of any law.

Signed: Dated:

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The Winston Churchill Memorial Trust of Australia - Report by Maurice Potrzeba - 2010 Churchill Fellow - Page 1 of 24

INDEX Introduction ……………………………………………………………………………………………………………..Page

3

Executive Summary …………………………………………………………………………………………….…….Page

5

Programme …………………………………………………………………………………………….…………………Page

6

Main Body …………………………………………………………………………………………………………..……Page

7

A Brief Overview of Brick Manufacture and History through the ages ……………….………Page  Medieval Period (1200 to 1485) ………………………………………………………………………..Page  Tudor Period (1485 to 1603) ……………………………………………………………………………..Page  Jacobean and Stuart Period (1603 to 1714) ……………………………………………………….Page  Georgian Period (1714 to 1837) …………………………………………………………………………Page  Victorian and Edwardian Period (1837 to 1914) ………………………………………………..Page

7 7 7 8 8 8

Historical Development of English Brickwork from the Tudor to Edwardian periods ...Page

8

Limes and Lime-based mortars for traditionally constructed masonry ………………...…..Page

9

Traditional Walls built with lime mortar …………………………………………………..…………......Page

11

Historic Forms of Jointing and Pointing ………..……………………………………………..…………...Page 12  Jointing …………………………………………………………………………………………………………Page 12  Pointing ………………………………………………………………………………………………………..Page 12  Re-pointing …………………………………………………………………………………………………..Page 12  Historic pointing styles …………………………………………………………………………………Page 12 Post-fired Curt and Rubbed and Gauged Work …..……………………..……………….………......Page 16  Cutting and Rubbing ………………………………………………………………………..…………..Page 16  Gauged work ………………………………………………………………………………………………..Page 17  Gauged Camber Arch work …………………………………………………………………………..Page 18  Laying Gauged work, including the Camber Arch ……………………………………….…Page 18  Gauged Niche Construction ………………………………………………………………………….Page 20 Conclusion ……..……………………………………………………………………………………..…………………Page 23 Recommendations ………………………………………………………………………………..…………………Page 24

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INTRODUCTION I come from a long line of bricklayers, being fourth generation. My great-grandfather, Anton, and grandfather, Wilhelm, were bricklayers and designers capable of drawing historically they would have been called „Artisan Architects‟. Being the last of the artisan bricklayers they were all very highly respected; as was my father too.

Anton

Wilhelm

Tony

Maurice

I have been involved with brick restoration and conservation since 1991 and it is now my intention to be the best bricklayer that I can and advance my craft skills and those with in the family business. I wanted to go the extra mile, to learn and complete work of a high standard and, hopefully, to be called on, Australia-wide, as someone with a repository of traditional skills that can be relied upon for quality brickwork; and to sensitively restore buildings. I knew to accomplish this mission I had to look outside of Australia to where these skills originated. This led me to search further afield and, after researching through the internet, to discover Dr Gerard C.J. Lynch LCG, Cert Ed, MA (Dist.), PhD Historic Brickwork Consultant from England, who is also an internationally acknowledged Master Bricklayer, an Educator, carver, author; and thus a person highly skilled and knowledgeable. I realised that this would mean I would need to travel to England to undertake a period of intensive studies with Dr Lynch, as he provided a full spectrum of lectures within brickwork from basic mortars to high end gauged work in his workshop. I was told by a friend (a Winston Churchill fellow) about the Winston Churchill trust and investigated the requirements of the trust, which then led me to apply for a Winston Churchill fellowship to travel to England to study gauged brickwork, niche construction, but of particular interest and importance, historic bricks, brickwork, joint finishes, as well as limes and lime based mortars to substantiate and ensure the correct approach to preservation of historic brickwork in Australia. Dr Lynch provides full training (both theory and practical) at his fully-equipped workshop in Woburn Sands, Buckinghamshire (about 75 kilometres north of London), providing a unique resource that meant I didn‟t have to go further afield; meaning a travel saving for the Winston Churchill Trust. After being successful with my application, and having travelled to the United Kingdom, I found that among the many benefits achieved through these studies, one important aspect highlighted to me was how the British approach the The Winston Churchill Memorial Trust of Australia - Report by Maurice Potrzeba - 2010 Churchill Fellow - Page 3 of 24

various aspects of repair, conserve, restore, and how they hold a philosophical approach, such as “truth to materials”. This being to ensure that any modern materials used are as close to the originals and to replicate craft methods used historically by craftsman in Britain/Europe. As a result of this emphasis there are huge differences to the materials currently available for repair work in Australia. This is an area I have huge concerns for when it comes to undertaking restoration work. For example, this currently applies to the range of bricks - types, textures, and hardness of bricks. The special low-fired rubbing bricks, required for gauged brickwork that I have seen, and now worked with, in England, are not available in Australia. As Dr Lynch pointed out, that while I was in England, learning and improving my craft knowledge and skills, somewhere, in a back street of Australia, someone was likely to be replacing an arch, or other brickwork on a heritage-listed building and using the incorrect bricks and mortar and ultimately defacing and devaluing the architectural heritage of this building. I am eternally thankful to the Winston Churchill Travelling Fellowship for granting me the funding and the privilege of travelling to England; both as a representative of the Winston Churchill Trust and my country, Australia. It has, without doubt, greatly assisted and increased my knowledge of the different types of bricks, limes, aggregates, mortars and the traditional and modern tools available along with their uses, particularly the increase in my skill level and, importantly, my confidence for undertaking crafted brickwork techniques that can be used in my undertakings of restoration work and which, without this funding, I never would have had such a great opportunity. It has been the most rewarding experience in my life and also for the furtherance of my business and the preservation of the buildings that I work on. Funding from the Fellowship only covered some of the courses that I initially intended to undertake and as a result I removed from the course a highly-specialised area of gauged brickwork associated with niche construction. After having completed my planned itinerary of studies with Dr Lynch, and found them to be so beneficial, I decided to extend my time with him and fund the additional niche construction course myself. I would also like to acknowledge and thank the two people who kindly acted as personal referees during the application process – Mrs Jacque Pearce (Pearce Architects) and Stewart Armstrong, the Executive Officer of the National Trust of Queensland. I would like to thank Dr Gerard Lynch (a true master craftsman) for his training and knowledge passed on to myself, also his lovely wife, Fiona who assisted with the compiling of my itinerary to meet the requirements of the Fellowship, for providing beautiful home cooked lunches every day of my studies and for both taking me into their lives. It should be noted that Dr Lynch is also a Winston Churchill Fellow (he obtained his Fellowship in 1997-1998) and was very happy that he could pass on all of his knowledge to a fellow, fellow.

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EXECUTIVE SUMMARY Maurice John Potrzeba 68 Lillian Avenue PO Box 296 Salisbury Qld 4107 Moorooka Qld 4105 Brick Restoration Specialist

Mobile: 0418 882 126 Fax: 07 3277 0443 Email: [email protected] Web: www.mozbiz.com.au

The Winston Churchill Fellowship to study Lime and Historic Mortar, Gauged Arches and Niche Construction – England United Kingdom. Highlights:  Firstly meeting and being educated and trained by Dr Lynch, and being allowed to meet a number of other professionals his work brings him into contact with.  Travelling to Dublin, Ireland, with the Lynch family (who are Irish) and meeting some of the people Dr Lynch associates, such as Geraldine Walsh Director of the Dublin Civic Trust and Anna Dolan Senior Architect with the Office of the Public Works (OPW) also based in Dublin.  Meeting with and the information kindly provided by Jim Matthews from H.G. Matthews, Handmaking Brickworks (information particularly pertaining to their rubbing bricks).  Meeting and information kindly provided by Andy Richardson (Brick and Terracotta Specialists) from W.T. Lamb‟s Brickworks – on handmade bricks.  Travelling to Gammel Estrop, Aarhus, Denmark to look at historic buildings rebuilt in the one spot providing training of old traditional skills used in the preservation of buildings (Ole and Gunnuv Forsingdale),  Studying pre-war buildings in Emden, Germany with Joe & Margo Freniks (Retired Town Mayor of twenty-five years and retired business executive of a local shipping company). Major Lessons and Conclusions: Restoration is prevalent in these countries with many good ideas. Denmark moves and rebuilds their historic buildings to create a small village thus providing training in building techniques and also providing a tourist attraction. England have a Construction Skills certification Scheme (CSCS) Heritage-endorsed card and Dr Lynch, as senior advisor to the scheme, also provides training under the Specialist apprenticeship Programme (SAP) in brickwork‟ Knowledge and craft skills and associated techniques. Refer to recommendations I was able to visit, discuss and record information of interest on various buildings of interest throughout England (Buckinghamshire, Bedfordshire), Denmark (Aarhus) and Germany (Emden) to successfully complete my fellowship. I plan to disseminate the information gathered through my report to the Winston Churchill Fellowship Trust through fellow work associates, Architects and training of apprentices and employees. The Winston Churchill Memorial Trust of Australia - Report by Maurice Potrzeba - 2010 Churchill Fellow - Page 5 of 24

PROGRAMME Week 1 8th – 12th November 2011  Introduction to Dr Lynch, his professional background, and to the outlined programme for the course, plus induction of Health and Safety, orientation.  Historical Development of English Bricks and Brickwork – lectures and site visits.  Subject – Limes and Lime-based mortars  Lecture – „Lime Mortars for Traditionally Constructed Brickwork’  Practical workshop – study of materials, slaking lime to putty, dry-hydrate, sand slaking and hot mix mortars.  Modern limes including NHL‟s – coarse and fine stuff mortar preparation.  Subject – Historic Joint finishes and Re-pointing  Lecture – „Historic forms of Jointing, Pointing and Re-Pointing’  Site visits to look at joint finishes 16th – 19th century properties.  Practical workshop – re-creating historic joint profiles. Week 2 15th – 19th November 2011  Subject – Cut and Rubbed and Gauged Brickwork  Lecture – „Introduction to Cut and Rubbed and Gauged Brickwork‟ and „Gauged brickwork: An Historical Overview’  Site visits  Practical workshop – study of materials, tools and equipment  Squaring, cutting and rubbing bricks from the templets Week 3 & 4 22nd November – 3rd December 2011 (Self funded)  Subject – Gauged Niche Construction  Lecture – „Gauged Niches’  Geometry and setting out and drawing a niche.  Preparation of templets from the drawing.  Preparing and cutting rubbing bricks from the templets. Week 5 6th – 10th December 2011  Subject – Tuck pointing  Lecture – „Tuck Pointing: The Grand Illusion’, an historical overview  Practical workshop – study of materials, tools and equipment.  The application of flat and profiled white and pigmented ribbons.  Course Review and Recapitulation of all the subjects covered during the course.  Questions and Answers  Conclude

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MAIN BODY A Brief Overview of Brick Manufacture and History through the ages Dr Lynch first of all took me on a journey back through history and down the timeline from the fourteenth century including lime-mortars, brick types and their manufacture, pointing, jointing, and finishes such as colour washing, as well as, cut and rubbed work and gauged work. Dr Lynch took me down this British timeline as, with our shared heritage, that is where we came from here in Australia; in order to better understand the influences on those early colonial craftsmen in the late 18th century. Medieval Period (1200 to 1485) - The main form of work in this period was the building of churches. As time progressed, private and civic work increased greatly. Early bricks were very uneven in size, length and shape. It was not uncommon to find bricks up to Fifty mm (50) different in length in the same wall. They could also vary up to Fifteen mm (15) in height. The bricklayer overcame this by laying the bricks with larger bed joints; Twenty-five mm (25) was not uncommon. In the late period of this time we started to see some polychromatic work using the overburnt headers of the bricks. The late twelfth century (medieval period) saw the introduction of craft guilds. The guild regulated apprenticeship training and crafts. Dr Lynch, in his tuition to me also indicated that the earliest records for apprentices in England date from the fourteenth century. Tudor Period (1485 to 1603) – This was when brickwork became popular in England over stonework. Bricks were handmade using only the topmost layers of brick-earth and clay, the deeper, more compressed layers where too hard to dig manually. One acre of land dug to one (1) foot deep would yield about one (1) million bricks. Initially bricks, which had been used by the Ancient Romans until they left England in AD c.412, where first re-introduced back into England as a result of rich merchants travelling abroad to Europe, where military campaigns and trading links led rich knights and wealthy merchants to want to copy the continental use of bricks to construct their own homes and castles. The English bricklayers, learning from the Flemish craftsmen, grew in confidence with more cut and rubbed and patterned brickwork appearing. Bricks were viewed as a prestigious material; and primarily only the wealthy could afford them. This later changed during the industrial revolution of the 19th century when machinery could manufacture bricks at a lower cost making then more affordable. Originally brickmakers where bought in from the Low Countries whereby the English learnt their methods of brickmaking. The traditional manufacturing of bricks was seasonal and consisted of four (4) basic steps: 1) During Autumn – Digging of the Clay 2) During Winter – Souring, or weathering to remove impurities, and frost action to break down the material. 3) During Spring – Brickmaking and drying the „green‟ bricks. 4) During Summer – Firing of the dried bricks whilst making more permanent

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updraft/updraught kilns or temporary clamps, the latter being constructed to any size, depending on the number of bricks required to be fired. When manufacturing the bricks, if the ground was suitable, the clay for the bricks could be dug and bricks made on site. By this method of making the bricks the cost was reduced by half in comparison with transporting the bricks twelve to sixteen kilometers. Mainly faggots of timber were used during the firing process of the bricks resulting in potash being left on the header faces of those bricks facing into the fire tunnels. From the intensity of the heat the potash would glaze onto the brick providing a beautiful grey-black colour. These bricks would normally be set as contrasting headers to the other orange/red coloured bricks, laid mainly in English-cross-bond in what is termed Polychromatic, or multi-coloured, brickwork. Jacobean and Stuart Period (1603 to 1714) – Bricks used during this period were made from as before, but standards of brickmaking continued to improve in respect of moulding, drying and firing, resulting in improved regularity and accuracy of shape as the period progressed. In 1605 King James 1st issued notice (proclamation) to the people of London to construct their fronts of their houses from stone or brick to reduce the risk of fire. The houses at that time were mainly timber-framed with a patterned brick infill. Georgian Period (1714 to 1837) – During this period sand moulding was introduced and later the „kick[er]‟ on top of the stock-board that formed the‟ frog‟ on the de-moulded brick. The kick is used to help force the thrown clay into the corners of the moulding boxes. Bricks were now the cheapest form of building material, but still considered prestigious for the building of mansions by the likes of highly acclaimed English architects such as Sir Christopher Wren. Victorian and Edwardian Period (1837 to 1914) – This period saw the Industrial Revolution and the introduction of brick making machines with the application of over one hundred (100) patents by the 1850‟s. As a result bricks became cheaper enabling affordability for the increasing middle class. With rail becoming a mode of transport, bricks could be sold even cheaper and all over the country. Although machines were making common and face bricks including patterned bricks, there was still a market for handmade face bricks. With the high level of building activity during this period we saw the complete disappearance of the Master, Journeyman and the apprentice: - And Master bricklayers became rare.

Historical Development of English Brickwork from the Tudor to Edwardian periods The Tudor style was the last phase of the Gothic era and saw the start of the Renaissance („re-birth‟) of classical architecture based on Ancient Greek/Roman styles and practices, this influence started in Italy and took approximately two hundred (200) years to spread to England. During the Tudor period bricklaying became popular and bricklayers became the central

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figure in the building trade as they possessed considerable skills and status, the very best, Master craftsmen were all educated, proud, conscientious, expensive and highly respected with the Master being given ermine lined coats – the Master (teacher) journeyman bricklayer acted in “Loco Parentis” (in place of the parents). An apprentice was required to agree to retain all trade secrets („mysteries‟), not to disgrace the master bricklayer; or cost him money. After qualifying as an apprentice they could then become a journeyman and travel to within one day outside of their guild area. During the sixteenth century apprenticeships were generally for a period of seven (7) years and you became a member of the Guild, typically named after a saint, the bricklayers were generally associated with the Blessed virgin, hence, “Our Lady‟s Guild of the Bricklayers”. The apprenticeship was usually commenced at the age of fourteen years and continued through to adulthood (21 years of age). Apprentices were immersed in Gothic and Tudor work traditions, and taught how to arrange and lay brickwork and the best were taught how to set out and prepare moulds for cutting to ornamental shapes the bricks, after they were fired, termed cut and rubbed work; that raised the best bricklayers to the status of a mason. The Master bricklayer was able to have up to two (2) indentured apprentices. Indenture meaning a contract between the Master (meaning „teacher‟) bricklayer and an apprentice this contract was in duplicate, folded and then cut along the top creating the „indents‟. The contract at the end of the apprenticeship was put together, so that the indents at the top of the contract could be matched; hence indenture.

Limes and Lime-based mortars for traditionally constructed masonry All forms of building Lime are calcium carbonate and could be in the form of seashells, egg shells, coral, marble, blue Lias and white and grey chalk. Limestone is the general name for a calcium carbonate bearing sedimentary rock, and chalk is a variety of lime stone, being of single cell, calcium carbonate secreting creatures. Marble is limestone that has been exposed to heat and pressure („metamorphic‟ – „change of form‟). All types of limestone or calcium carbonate have to be fired to become quicklime. There are two classes of lime: The first is „air lime‟, or „non-hydraulic‟ – as it only hardens by a process of absorbing carbon dioxide (Co2), termed „carbonation‟. It is ninety-five percent (95%+) pure calcium carbonate – it sets initially by absorption of water into the brick and then by carbonation. When used externally, some pozzuolana is added to aid the set.  The second class is a „water lime‟ or „hydraulic lime‟ – that contains silica etc. that becomes reactive with lime during firing, and has initially an internal set, which can occur under water and which if it occurs in the presence of the atmosphere, is followed by carbonation. It is important not to confuse the term “Hydraulic lime” with “Hydrated lime”. Hydrated lime is simply quicklime that has had water added until – with minimum water it becomes a powder, or slaked to a „dry hydrate‟ – traditionally slaked dry - hydrated lime is good to use for restoration of brickwork. With excess water added during slaking to the The Winston Churchill Memorial Trust of Australia - Report by Maurice Potrzeba - 2010 Churchill Fellow - Page 9 of 24

quicklime it becomes what is known as lime putty. Modern „High Calcium‟ hydrated lime which is primarily intended to be used only as a plasticiser with a cement-based mortar: and is not suitable for restoration work. Mortars should contain five (5) properties: 1) Be of adequate strength – fit for purpose, compatible with binding and compressive strength but never harder than the material it is binding. 2) Durability – once set it should resist the action of weather and pollution. 3) Porosity – similar to the brick, particularly in old brickwork. 4) Workability – fresh state workability, not fatigue the craftsman unduly, should hold together when worked and be able to leave the trowel cleanly and stiffens slowly. 5) Aesthetically pleasing – joint finish is essential with half bond being about fifteen percent (15%) of the surface and header bond being about twenty-five percent (25%) of the surface area. Consistency of colour is important. Mortars usually consist of three (3) components: 1) Binder – Lime, Natural Cement, Artificial Cement giving the binding strength workability, solidity (not density), porosity, tensile strength and durability. 2) Filler – Silica Sands or crushed limestone and water. 3) Plasticiser – This can come for the binders like Lime and natural cement, but not with Artificial (Portland) cement which would require lime or a chemical air entrainers, the air bubbles acting like ball bearings that work well with soft sand (round grains, not angular). During my studies with Dr Lynch, we discussed slaking and although I had some knowledge about slaking quicklime, he provided much additional information on the varying methods of slaking quicklime. We proceeded to slake the quicklime to putty and also a dry hydrate. It should be noted that when slaking to putty you should always add the quicklime to the water and not the water to the lime. When gradually adding lime to the water, do not let it boil, as this will form a coating on the granules of quicklime resulting in granules not slaking correctly. These un-slaked pieces of lime when used in pointing could then slake in the wall causing failure of the mortar.

After slaking the lime putty (figure 1) it was pushed through a sieve to remove impurities (figure 2), such as flint, and any un-slaked (under or over-burnt) lime. The putty should have a good wax-like shine. We also slaked more quicklime with a minimum of water to create a crude dry-hydrate (figure 3), or powdered lime.

Figure 1 - Lime Putty

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Figure 2 - Sifting out Impurities

Figure 3 – Slaking to a dry-hydrate

This was then screened and finely sifted to remove impurities. This traditional dry-hydrated lime is good to use mixed with fine silica sand in a „fine stuff‟ mortar. It should be noted to use safety glasses and equipment at all times as the quicklime can be volatile and very dangerous to the eyes, skin and to ingest. The definition of „Fine Stuff‟ is that it is made from lime with a fine grade of silica („silver‟) sand water. When aggregate is added it is then referred to as “Coarse Stuff”

Traditional Walls built with lime mortar Traditional walls constructed with lime mortar achieve their resistance to loading from their mass and „dead-load‟. The mortar joints act like a flexible gasket, rather than the „gap-filling glue‟ that modern cement-based mortars provide. This allows movement with minimal cracking. These solid walls are said to breathe and the overall wall to have the same effect as an overcoat with water being slowly absorbed and passing into the wall, but then evaporating from the brickwork with the return of dry weather, mainly through the joints and leaving the wall dry. Modern walling is a thin, structural envelope and the mortar is intended to be a gap filling glue, meaning the masonry behaves like a raincoat because the Portland cement is hard, inflexible, and non-porous, therefore, shedding the water down the face. As the cement mortar is rigid these walls require control, or expansion joints to facilitate their movement without cracking.

Historic Forms of Jointing and Pointing Jointing – Jointing was the first way of finishing the mortar. The bedding mortar, between the freshly laid bricks, once sufficiently stiffened, was ironed smooth to various profiles. The advantages of this method are a unified solid joint and a saving on labour and extra costs. Its disadvantages are a possible lack of consistency in colour and strength

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in the mortar mix, and with ambient weather conditions playing a part in the quality of its finish. Pointing – Pointing is the applying of a separate and finer superior strength mortar after completion of brick work. Pointing was first used from around the early seventeenth century. It had the advantages of a higher quality of joint finish, uniform colour and strength, greater choices of joint styles and also a cleaner finish. Its disadvantages were, that it was expensive due to higher labour costs, increase in time to complete works, and a possible lacking in the pointer‟s knowledge and skill which can cause a failure in the uniting of the older bedding mortar and new pointing mortar, or „stopping‟. Re-pointing – When an old wall has joints that have eroded or are allowing the ingress of moisture then it will require re-pointing, but this must take into account the importance of allowing a wall to breathe, by using a traditional lime-based mortar with an open pore structure that absorbs water but allows drying out. Never ignore the original joint profile, seen below the eaves, or window cills, etc., and always execute re-pointing in accordance with the prevailing weather conditions. Historic pointing styles – During this part of my studies with Dr Lynch we sieved some course-grained sand to achieve finer graded sand - This was an exercise to show that, in the absence of suitable sand, you can, with time and the correct techniques, turn that sand into one that is ideal for pointing use. We then took this sieved sand and mixed it with an appropriate grade of hydraulic lime to a volume ratio of 1:2 and dry sieved this mix back and forth to ensure a thorough mixing of the two materials. It was then mixed using glue size water to a stiff modeling clay consistency deemed suitable for pointing. Glue size is manufactured from keratin obtained from sources such as rabbit skin, cowhide, horns and hooves etc. When natural ochres, as pigments are used in a traditional colour wash, as a stain, or dye, on the face of brickwork, common alum, or potash alum is used within the wash to fix the ochre as a mordant, the glue size enabling it to stick to the walls prior to pointing. Dr Lynch then provided practical training in the techniques for all the different historic jointing/pointing finishes; as well as colour washing. The historic pointing styles learnt were:  Fifteenth Century Struck, Double-Struck joint (figure 4)  Struck and Ruled (figure 5)  Ruled work (figure 6)  Ruled and Pencilled work (figure 7)  Overhand Struck and Cut – this style is probably the most common used in Queensland. (figure 8)  Weathered and Cut joint  Seventeenth Century Bastard Tuck jointing (figure 9)  Tuck-pointing (figure 10)  Tuck-pointing with pigmented ribbons (figure 11)  Bastard Tuck-pointing

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Figure 4 – 15th Century Double-Struck joint

Figure 6 – Ruled work (Houghton House)

Figure 8 – Overhand Struck and Cut

Figure 5 – 17th Century Struck and Ruled joint

Figure 7 – Ruled and Pencilled work

Figure 9 – 17th Century Bastard Tuck jointing

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Figure 10 – Tuck-Pointing

Figure 11 – Tuck-Pointing with beaded pigmented ribbon

Once I had obtained a suitable proficiency in the above styles, Dr Lynch allowed me to undertake advanced Tuck-pointing (Pigmented and ornamental ribbons) The most rewarding of these styles for me was the undertaking of the tuck-pointing due to its excellent and accurate final appearance and the level of workmanship involved, (set out of tuck-pointing - figure 14). I have not seen modern examples in Australia finished to such a high degree of excellence. Tuck-pointing was developed in the late eighteenth century to imitate gauged work because it had become expensive to construct. Tuck-pointing is a process of mixing a sieved course stuff with ochres, to form a pigmented „stopping‟ in order to achieve the same colour as the brickwork that is to be pointed. The stopping is then laid into the joints and filled flush. When it has tightened, or stiffened, sufficiently it is then rubbed-up (figure 12). Using a leveled feather-edge board or straight-edge, a fine groove is applied to the stopping and the particles created carefully removed with a light brushing (figure 13). Once this process is completed, then one applies the white/cream coloured lime: fine sand mortar ribbon (sometimes called the tuck) using an appropriately sized jointer, or tuck tool, to pick-up the mortar from the straight edge and press it onto and along the grooved stopping, moving from right to left along the length of the feather-edge board. Once all the ribbon is applied, one takes what is termed a „Frenchman‟ (a sharp knife with a small turned up hook), that is carefully run it along the feather-edge board to trim the excess putty from the newly applied ribbon, firstly from its top and then bottom (figure 15). The perp-ends, or the vertical joints, are then completed in the same manner as the horizontal beds but using the feather-edge board in an upright position (figure 16). This entire process was repeated several times using pigmented stopping and ribbons. Tuck-pointing was one of the many areas where Dr Lynch really perfected my techniques, fine-tuned me and disseminated knowledge to further enhance my pointing skills. An example of the finished work I completed during my course (figure 17).

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Figure 12 – Rubbing stopping to a smooth finish

Figure 13 – Grooving the stopping

Figure 14 – Set out of perps

Figure 15 – Beds laid onto the grooved stopping

Figure 16 – Trimming the perps

Figure 17 – Finished Tuck-pointing

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Post-fired Cut and Rubbed and Gauged Work Cutting and Rubbing - The rubbing bricks are from high-silica bearing brick-earth or clay that has been low-fired below the point of vitrification (900 degrees Celsius) so there is no fireskin, allowing the bricks to be cut or carved without detriment (figure 18).

By the later nineteenth century they were generally oversized so that they could be cut to shape, using the bow-saw fitted with a twisted wire blade of steel wire. To undertake gauged work, with the soft rubbing bricks firstly examine them for any defects as these can be rubbed, or cut away, on a flat piece of sandstone. Figure 18 – Rubbing brick (T.L.B.)

After inspection one rubs the face and bed of the brick to obtain a good surface, whilst testing with a try-square to obtain a true „squared‟ shape (figure 19).

Figure 19 – Testing for square

Rubbing should always take place using a circular motion always pushing away from your body at the end of the motion to lift the rubber clear of the stone. The prepared brick is then placed into a cutting box with an adjustable bottom which can be set to the desired „templet‟ size obtained from the previously drawn plans. The cutting box is placed onto a cutting bench and the rubber is held down firmly by means of a support, or strut, braced under pressure from an overhead beam.

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The brick is then cut to the shape of the box using a bow- saw and wire cutting blade (figures 20 and 21).

Figure 20 – Cutting a „”Ovelo” with the bow-saw

Figure 21 – Using a bow-saw

Once the brick is cut it is then vacuumed clean of all dust, checked and then carefully rubbed with a piece of timber, or a steel file, in order to produce the desired fine face as a finish on the brick. It is imperative that all bricks are of the same exact size as they will be laid (in this instance) with a one millimetre (1mm) thick joint. This is also known as a sixpenny joint as it is the same thickness as an old sixpence – or „tanner‟. After checking all cut bricks for accuracy of size, they were dry-laid to ensure a correct fitment. Gauged work – Gauged work was, and still is, considered to be the highest level of expression of a craftsman bricklayer, or rather a „brick-mason‟. In this part of my studies, Dr Lynch (considered the world‟s leading authority and craftsman) taught me the geometry and how to set out, draw and construct gauged ashlar work, gauged arches and we began a gauged niche. Cut and rubbed was from Flemish influence and imported into England during the fifteenth century: and was initially laid with nominal joints. Gauged work was laid with finer joints than cut and rubbed work. An example of early gauged ashlar brickwork is to be seen on the Loggia‟s at Houghton House (figures 22 and 23).

Figure 22 – Houghton House

Figure 23 – Early gauged Ashlar brickwork

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Gauged Work defined a superior finish suitable for the erection of classical enrichments such as arches, aprons, cornices, pediments and niches where the finer joints allowed the overall brickwork to suit the architectural whole, where standard sized joints would have drawn attention to themselves. Gauged Camber Arch work – Again full scaled drawings for the arch were drawn before its construction, to assist with the understanding of the geometry associated with the arch. Dr Lynch said a memorable saying, “Theory informs and practice convinces”, which I certainly found to be true. After the line representing the bottom of the arch was drawn, and the centre line found by geometry, the span and depth of the arch must be set out, in this instance a span of 450 millimetres was chosen with an arch face depth of 200 millimetres, and 60 degree skewback angle and finally, a camber; or gentle curve to the soffit based on 3 millimetres per 300 millimetres of overall span. Another general rule is that for every 300 millimetres of span in the opening, 25 millimetres of skewback angle can be allowed. From these drawings, templets were carefully made to take and mark out the bricks for rubbing and sizing (figure 24).

Figure 24 – Final rubbing of a “Voussoir”

Figure 25 – “Joggles” cut into the “Voussoirs”

Arch bricks are correctly referred to as “voussoirs”. To stabilize the arch the bricks are usually cut on each internal bed on opposing sides at the top to form a cavity called a „joggle‟ (figure 25). This is usually filled with a strong mortar grout after the voussoirs have all been set into their final positions. Once again all the prepared bricks were dry-laid to ensure correct fitment before proceeding to lay them. Laying Gauged work, including the Camber Arch – The lime putty mortar should always be mixed to the proper consistency with fine silica sand added, (the quantity of sand depends on joint size), the resultant mortar having a waxy shine with the consistency of double cream; and this is placed into a small „dipping box‟.

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The bricks should be firstly dipped into water to remove any dust that may have accumulated on the surface ensuring that the bricks are not saturated. The joint is achieved by „dip-laying‟, lowering the brick in a horizontal position from back to front onto the prepared lime putty – to pick-up and prepare a joint the thickness of a sixpence, lifted in an upward direction before being carefully placed and bedded into its final position (figure 26).

Figure 26 – Bedding a “voussoir” into position

Before completion of the arch work a section of the voussoirs are dry-laid to ensure correct fitment (figure 27). After completion of the arch-work always working from both sides towards the centre, or „key brick‟ position, the joggles are filled. When the joints were sufficiently dry, usually the next day, we carefully trimmed the snots and filled any holes in the joints. After the work has completely dried, it can be rubbed over fully with a smooth piece of brick or stone to give it an entirely smooth, flush finish. Below is an example of my finished arch-work after layering and rubbing (figure 28).

Figure 27 – Checking for fitment of arch-work

Figure 28 – Finish arch-work

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Gauged Niche Construction – Dr Lynch provided a brief history on niches. The word niche is from the Italian word “nicchio” meaning “shell” and was usually semi-circular or semi-elliptical on plan and covered with a dome or hood of the same material – the intention being to house a statue or trophy (figure 29).

Figure 29 – A completed niche in Dr Lynch‟s workshop

Figure 30 – Drawing the niche using trammels

The lower part of the niche is referred to as the „body‟ and the upper part a „hood‟. In the past constructing a brick Niche has been considered to be the supreme test of a bricklayers skill as a first-rate craftsman. The joints in a gauged niche range from 0.5 of a millimetre to 2 millimetres in width. To construct the niche it is first essential to draw all plans, elevation and section, as with the gauged arch these were drawn full size to facilitate the making of templets in order to accurately cut and rub all the bricks (figure 30). After learning basic geometry while drawing the plans for the niche and after completion of these drawings, I undertook the dry construction of the niche using Dr Lynch‟s forty (40) year old, original T.L.B.‟s obtained from his work on the cut and rubbed chimneys at Hampton Court Palace (d.1515).

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He insisted that I use these quality „rubbers‟ as I had come all the way from Australia. These bricks were cut to size using the bow-saw and cutting boxes technique. One cutting box was used for the height, or gauge (27 mm) of each course of the body, and one for each of the many curved voussoirs bricks for the hood, consisting of: - curved stretchers, halves and closures (figures 31 and 32).

Figure 31 – Cutting a curved niche stretcher

Figure 32 – Rubbing a niche stretcher

A single double curved „boss‟ used for the central radial point was cut and rubbed for use at the rear of the hood (figure 33). The bricks for the body and the hood where all dry-laid using templets for the radius of the body and a shaped centre (figure 34) was used for assembling the hood: - the external surface of the hood centre is usually finished in plaster, in order for all the hood courses to be carefully marked onto it.

Figure 33 – Scribed “boss” ready for rubbing

Figure 34 –Dry-laying and checking of hood “voussoirs”

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The dry-laid bricks were set out using the sixpenny joint size, (one mm) (figure 35 and 36). This would then be laid when I return next year in the same manner as previously described in the laying of gauged work. After drying of the mortar, and the careful removal of the hood‟s centre, the entire work can then be rubbed over to clean it and remove any brick defects.

Figure 35 – Dry-laid bricks with one millimetre joints

Figure 36 – Side view of Dry-laid bricks

It was interesting to note, the amount of time it took to cut and shape the bricks – it took about three days to cut and rub approximately 230 small bricks to be used for constructing the niche. A third of these bricks where placed in another cutting box to cut them into radial voussoirs for use in the hood.

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CONCLUSIONS It has become evident that special skills and techniques are required when undertaking restoration/conservation/repair work of old brickwork. Things that need to be taken into consideration are:  what type, texture or hardness of brick was used,  when and where were the bricks made,  what type of mortar was used for the joints etc. (eg. lime)  is there any modern material available that could be used that would replicate the original materials  what is the joint finish  what techniques were used in designing the brickwork.  the architecture, the brick detailing (moulding) and “cutting and rubbing” to execute arches, vaulting, domes, niches, etc. As Dr Lynch pointed out, that while I was in England, learning and improving my craft, knowledge and skills, somewhere, in a back street of Australia, someone was likely to be replacing an arch, or other brickwork on a heritage-listed building and using the incorrect bricks and mortar and ultimately defacing and devaluing the architectural heritage of this building. It distresses me greatly to find that this is also the case here in Brisbane, where certain projects have been undertaken by people who have used unsuitable materials and tradespeople resulting in irreversible damage to our build heritage. What regulations or procedures can be implemented to safeguard against this happening? My time spent with Dr Lynch has completely changed the way I approach my restoration projects by way of investigating the history of the project and it‟s bricks and mortar etc., I am eternally thankful to the Winston Churchill Travelling Fellowship for granting me the funding and the privilege of travelling to England; both as a representative of the Winston Churchill Trust and my country, Australia. It has, without doubt, greatly assisted and increased my knowledge of the different types of bricks, limes, aggregates and mortars. I have a greater knowledge of the traditional and modern tools available along with their uses. The completion of my studies has particularly increased my skill levels, and importantly, my confidence for brickwork conservation techniques that can be used in my business of restoration work and which, without this funding, I would not have been able to undertake.

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RECOMMENDATIONS As mentioned previously, Dr Lynch pointed out, that, while I am in England, learning and improving my craft, knowledge and skills, somewhere, in a back street of Australia, someone was likely to be replacing an arch, or other brickwork on a heritage-listed building and using the incorrect bricks and mortar and ultimately defacing and devaluing the architectural heritage of this building. Some aspects for consideration: 

It would be a great benefit to Australia if Dr Lynch was invited to speak with heritage architects, representatives from the Department of Environment Resource Management and National Trust.



Australia needs to work with all states and include our neighbour New Zealand to have all people with heritage skills to be recognized and licensed with a form of heritage card similar to that recently introduced into the British system or a registrar of accredited professionals and trades people with skills in conservation. This could simply be in the form of approval lists held by ie. Heritage Department, DERM and local councils.



Heritage architects need to have more control over the principle contractors working on heritage sites with the Architect signing of on the approved work.



If a brick building is unable to be saved from demolition the façade could be retained and conserved for future generations



Acknowledge that extra time is required to undertake heritage works in comparison to new works.



Increase awareness of traditional techniques in brick conservation (ie. seminars, demonstrations, reports and training of younger generations)



Increase awareness and use of traditional materials and their sources in Australia or overseas via a registry of heritage suppliers



Raise awareness that not all work can be accurately tendered before investigations are carried out. Promote early investigations before tenders are sent out to minimise the risks of cost blow outs during construction.



Building restoration/conservation work should be treated in a case by case basis as there is no one shoe that fits all. A mortar analysis should be conducted for each restoration project on buildings to best replicate the existing mortar.

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