The Art of Brickwork

Progress, Volume X, Issue 2, 1 October 1914, Page 45

The Art of Brickwork

By R- NEWTON VANES, A.R.1.8.A., Dunedin Wgy/

) Being a Paper read before the Institute of Architects at Dunedin ( CS=^'''V'am\ ~— * —-— n -

INTRODUCTION

That brickwork is the cheapest and most common form of building material of a permanent and fireresisting nature is a well-known fact; nevertheless, it is a material capable of a very fine treatment if properly manufactured and built. Some of the finest domestic work both in England and America is constructed of brickwork, while innumerable other buildings both large and small have the main body of their walls of brick, and depend largely for their effect on the character and quality of the brickwork. It is not the object of this paper to treat with the manufacture of the brick, but rather with the finished article, its history and present day use and abuse. HISTORICAL SKETCH EGYPTIAN PERIOD The manufacture and use of bricks may not be as old as the hills, but they certainly date back to the time of some of the later pyramids. Brickwork was used extensively in the construction of a pyramid in 2,400 8.C., and, from the manner in which the Egyptians used it in this instance, the actual invention of the brick must have taken place at a much earlier date. In their monumental works and temples, however, the Egyptians principally used stone, though it is evident that dwellings were erected largely of brick. The Egyptian brick was a crude and sundried article, which was not fire-burnt, and was generally faced with stone, acting only as the core of an immensely thick wall. These sun-dried bricks were re-inforced with straw. CHALDEAN AND ASSYRIAN PERIODS As Egypt abounded in stone, there was not the need of the universal adoption of a brick construction. The Plains of Chaldea, however, were devoid both of wood and of stone, and it was therefore in this land that the brick first came into great prominence as a building material. We have early Biblical reference to the use of brick in these plains. "And it came to pass as they journeyed East that \ they found a Plain in the land of Shinar, and they "dwelt there. And they said one to another, "Go to "let us make brick and burn them thoroughly." "And they had brick for stone, and slime had they "for mortar."

The Chaldeans, followed by the Assyrians and Persians used brickwork in a most extensive and comprehensive manner. Sun-dried bricks were very largely used at first, and subsequently kiln-burnt ones. They, however, took no risks in their con-

struction, and their Architects were evidently not unduly harassed by clients who desired, a £I,OOO effect for £SOO expenditure! Their brickwork was rather a heap of bricks than what we would consider a brick wall. For instance, in the Hall of Columns at Persepolis, the brick walls were no less than 10ft. Bins. thick. Needless to say, there is no mention of strapping and lathing the walls to keep signs of dampness from the exterior, nor do their inscriptions refer to the use of toxement in the plaster! Brick arches and vaults were evidently constructed as sun-dried specially moulded brick voussoirs have been discovered bedded in clay which must have been run into the joints in a wet state. The mortar, however, was often pitch obtained from the pitch wells, while later calcareous earths were used. Decorative brickwork was extensively employed, unglazed in various colours and moulded, also moulded and glazed and enamelled in various colours. One of the early buildings in Lower Chaldea is faced with vitrified bricks and the upper storey was vitrified after erection by some process we do not now understand. This storey now forms a mass of slag. Diaper work of various patterns and low relief carving formed delightful ornamentation and symbolic friezes in various buildings and have stood the ravages of time so well, that fairly complete samples of this early work are now in the Louvre and British Museum. GREEK PERIOD The Greeks were not by any means a brick using people, and why should they have been when marble was to be had for the mere quarrying of it? In the early Greek period, however, AA-alls of the temple were often of poor masonry or of brick, and it was on this account that the dado became a structural necessity, as they protected the lower portion of these walls with, thin stone slabs. THE ROMAN PERIOD The next great style was that practised by the Romans, and in this period bricks very similar in character to our red kiln-burnt brick Avere made and used. In their later works, hoAvcver, they used them in a different manner from the Assyrians. While the latter made the whole Avail of brick, the Romans more generally used concrete for the main body ,of the wall, and faced it with brickwork. That the principal building materials of the early Romans was undoubtedly the brick is evident from the boast of Augustus that he found Rome of brick and left it of marble. Among the ancient writings are lengthy

descriptions of unburnt brick and of the precautions taken to preserve the walls and rules relating to the thickness of the walls, the manufacture of bricks and the length of time they should be kept before being used. This undoubtedly goes to prove that brickwork was of universal use and the manufacture

the concrete comprising the main body of the walls, the triangular shape making an excellent bond with the concrete. The construction of their vaulting was seldom of radiating solid brickwork, the brickwork to these generally consisting only of arched ribs round which the concrete was placed, and upon

of the brick arid the construction of the walls were arranged on a scientific basis and carried out to rules and regulations. A most interesting form of Roman brick, and one very largely used by the Eomans, was of a triangular shape on plan and about If inches thick. These were used to face up

which the temporary boxing was probably supported. The famous Dome of the Pantheon is an exception. As far as it has at present been examined, viz:— lower half and top rim, it consists of a tremendous mass and thickness of brickwork, the bricks of which were not laid in the form of radiat-

ing voussoirs, as one would imagine, but on an almost horizontal bed, the successive courses slightly overlapping. It is rather an astonishing fact that these courses have a slope down outwards of about 1 inch in 2 feet. What the intermediate portion consists of is not known, but it is 4 feet thick and it is presumed that it is of brickwork with possibly radiating arches. BYZANTINE PERIOD "The exteriors of the buildings belonging to that period which we term Byzantine depended largely upon brickwork for their effect. Stone seems certainly to be the most accepted material for all large or monumental work and we find that the art of brickwork is strongly developed only in the countries which are deficient in good building stone. This is the case in the region round about Constantinople where Byzantine art flourished, and no doubt accounts for the extensive use of concrete and brickwork in this district. In their construction, the Byzantine Architects followed the example set by the Romans, and used the brickwork as the casting for the main body of the wall which was of concrete. The bricks which they used were only 1| . inches thick and the mortar joint was of the same thickness as the brick itself. Of course with such fat joints a considerable settlement took place. They therefore ran up the shell of the building and allowed it to settle before slabing up the interior walls and floors with marble and the domes and vaults with mosaics. The mortar thus became a very important factor and great care was taken with the choice of materials for it and the mixing of them. It was composed of lime, sand, and crushed pottery, tiles, or brick, and was as lasting as the best Roman mortar and equally hard. To give the necessary relief to the exterior, the bricks were varied, all sorts of designs being indulged in, as the chevron or herringbone pattern, thus giving a greater richness and play of colour. The same class of construction was often used for their domes as for the main walls. In many instances large flat bricks were used and laid on horizontal joints, the structure being gradually corbelled out to the Domical form. These domes were constructed without centering. Another very interesting form of construction used by them for dome work is one so closely allied to brickwork as to be worthy of notice. They used earthenware hollow pots and fitted them one into the other, surrounding the whole in concrete, thus forming a very light and strong structure practically on the same principle as our present day hollow terra-cotta fireproof floors. THE BEAUTY OF OLD BRICKWORK And so we might continue with all the styles that have existed up to modern times. There is a warmth and charm about most old brickwork which is certainly lacking in our colonial article. I recall with pleasure watching the last rays of sunlight striking upon the old Norman brick tower of St. Alban's Abbey. The mellowed and yet rich tints in this tower are a delight. Age may have a lot to do with them, but the bricks themselves must have been good in the first place. This delightful

characteristic which applies generally to old work and also to quite a good proportion of modern work in England is hard to describe. It is a somewhat elusive quality, but if present it can never be passed without a second look, and the thought invariably flashes through the mind, "what excellent brickwork. ' DESIRABLE QUALITIES IN NEW BRICKWORK This quality of excellence, I take it, depends on several factors which might be enumerated as follows : 1. The colour of the individual bricks. 2. The method of laying them. 3. The colour and method of pointing. 4. The proportion and size of the individual bricks. 5. Thickness of the joint. So far, the points touched are hardly debatable, and I think you will have agreed with what I have said. Now we come to considerations which are open to argument and where individual taste is largely concerned. I shall, therefore, give a few somewhat fragmentary opinions of my own on this matter, which may not be in exact accordance with yours. COLOUR Eeferring to the divisions in the order before given, the first point is the colour of the brick. Whatever the colour is, each and every brick in the wall should not be absolutely the same colour. An unbroken mass in one tone is not to be found in nature and is quite inartistic. A painted surface is the only one that is uniform, and it, purely on account of this uniformity, never looks as well as a surface of unpainted material. You may say that an Oamaru Stone front is all one colour. So it is at first and it is then that it looks its worst. It is far more beautiful in after years when each stone has weathered to its particular shade. Now brickwork does not change much with exposure, therefore the bricks should be slightly varied in tone when taken from the kiln. It is in this respect that the clay burnt brick has the pull over the pressed sand brick. Unless great care be taken with picking over the bricks, there is always present this play of colour with the former giving a life and texture to the wall which is lacking in the sand brick. This drawback may, of course, be overcome mechanically by the discreet introduction of sand bricks of quite different colours in the form of patterns. Though personally I consider that the sand brick can never equal a first class burnt brick in the matter of colour, except that it somewhat resembles a limestone in its composition and therefore should weather like a lime-stone, and so ultimately give a play of colour. lam not advocating that brickwork should be like Joseph's coat—far from it—but that it is necessary that there be just* a fraction of a tone of difference between each individual brick in a plain wall, if the wall is to possess the charm which belongs to much of the old work.; ! It is evident that the colour effect of the wholfe

wall depends upon the colour of each unit, and for the mass of the colour to be pleasing, the general

tone of the brick must be good. "We certainly have this variation of tone in our Dunedin bricks, but I think that the colour itself is not all that it could be. It seems to lack richness, and is too much of a pinky shade, whereas more orange or purple tones are to my mind more pleasing. I do not think it would be a very difficult matter for the manufacturers to experiment by adding some ingredients to the raw clay, for the purpose of ascertaining whether the colour could not be improved, quite cheaply and with little trouble to themselves. BONDING The next point is the method of laying or the style of the bonding. There is no doubt that the spacing of the joints and the insertion of bats are carried out in a somewhat haphazard method in Dunedin. The size of the brick varies considerably; this no doubt may account very largely for the defect. A common defect which is quite fatal to the appearance of a wall is the irregular fashion in which vertical joints often are placed one above the other. Unless all vertical joints are in a true straight line, there is a decidedly ragged appearance. As far as general effect is concerned, there is no doubt that Flemish bond is far ahead of all other styles for the majority of the brick walling. In our Residential, Ecclesiastical and similar work, I think we might well follow the lead of the Byzantine Architects, and more freely adopt the use of patterns and relieving courses etc. The new Presbyterian Church at Invercargill has some most interesting brickwork, and shows what can be done here if we care to take the trouble and insist on getting what we want. In this Church, as well as relieving courses of various coloured bricks, the ordinary walling in arch spandrils and similar places is set herringbone fashion and in various other patterns. I think if we ceased to use rough cast in small patches and cement facings, and obtained our relief and play of colour from the judicious use of say chipped clinkers and sand bricks in various tones and set in the form of diaper work and herringbone etc., we would obtain much more pleasing results. However excellent the brickwork, I think it is in most places quite spoiled where plain cement compo facings and dressings are used. The cold grey of the cement invariably clashes with the colour of the brickwork, and quite kills its appearance. If the cement work is tinted with hydraulic lime, as in the Public Library, a warm tone results which harmonises with the brickwork and gives a much softer and

pleasing effect. I have noticed that many buildings in and around Dunedin have looked very much better just when the brickwork has been completed and before the plasterers have got to work. This has led me to the belief that we largely spoil our buildings in the finishing of them off, and that, whereas there is a general appearance of uniformity of surface about the semi-finished building, this

desirable quality is, in many instances, totally spoiled, and the building made to look fussy and disjointed by the indiscriminate tacking on of patches of plaster. If the walls were relieved by coloured bricks and by panels and bands of clinkers and by chevron and diaper work, a far more modest and

becoming structure would result and the harmony and continuity of the wall surface would not be interrupted and disjointed by harsh surfaces and disagreeable lines. For the finish of copings, sills, fire hobs etc., the plain brick on edge is quite simple and costs no more than the ordinary flat method, but it adds a decided finish to the work and gives it some character.

I do not think that we pay nearly enough attention to these small details, and allow the bricklayer to set his bricks as he thinks fit, provided he keeps a thin joint and an even face to his work. Another relieving feature often used in England, but seldom seen here, is the tile creasing. The use of thin tiles with fat joints is centuries old, and for relieving horizontal courses, small arches, projecting labels over openings and oversailing courses, is I think, both simple and delightful. "We are hampered here in not having the necessary flat tiles. Shingle tiles and Marseilles floor tiles are very expensive, and dished roofing tiles unsuitable. I see no reason why the brickmakers or terra-cotta workers should not make

and stock plain flat tiles say about 6ins. x 9ins. x 1 in. thick, provided we make a custom of using them.

(To be continued)