Tauf

To distinguish this type of mud brick from others (such as adobe, which is from the Arabic atTaub) the Arabic word is used to specify mud bricks from Syro-Mesopotamia, which in current times are much the same as those used through the Islamic Maghreb, Middle East, Horn and Central Asia.

There is no exact English equivalent for the Arabic word tauf. The French word pisé, often used in the archaeological literature, is inexact in that it implies the pressing of rather fluid mud between built forms. The Spanish-American usage adobe covers either simple sun-dried mud or sun-dried mud-brick walling. In Iraq tauf walls are still used, generally as garden or courtyard walls, and forms are not employed; nor does ancient tauf show traces of the impressions of forms. A tauf wall is built of a mud mix of sufficient fluidity so that the lowest "course" may be molded with the builder's hands, with a vertical face on either side, to a height of about 3 or 4 inches without slumping [often on a foundation of rough field stone]. Having laid the first "course," the builder simply waits a day or so for complete sun-drying before he adds the second "course," after which he must wait again, and so on. The mud mix contains straw or grass to prevent cracking, just as does that used for preparing the later sun-dried mud bricks (libn [الطّوبة]). Braidwood and Howe 1960, p 40

Nomads erected tents and marsh dwellers built with reeds, but the arrival of permanent agricultural settlements heralded new construction techniques. The earliest such method was with tauf/pisé, whereby lumps of clay or mud were prepared with little or no shaping, then stacked with no real planning to build walls. Attested at Hassuna in the north, the lumps were fashioned from clay dug from the river that was left out to dry; at Kish, this very method is well attested in later eras for the building of foundations.

Tauf of clay or a mud and straw mixture was still made in later eras, though just for animal shelters and other more temporary buildings. However, tauf precluded sophisticated or tall architecture and in the south these lumps had already given way to sun-dried mud bricks.

Mud bricks were made by mixing mud and straw, pouring this into a mould, removing the mould and letting the bricks dry. The mixture was most conveniently made by digging a pit near the banks of a canal, then drawing water from the canal to make a pit of mud. Chopped straw was typically added to improve the consistency and then the mixture was shaped using a mould. The mould was a simple four-sided rectangle, sometimes subdivided so two bricks could be poured at once, averaging 3.50 cm. That it was made of wood is shown by the markings left on some excavated bricks.

The bricks were not moulded on special ground, as shown by the sherds and other rubbish often found sticking or impressing the bases of bricks. Once the top was shaped (varieties in this technique addressed later) the mould was removed, the thick mud keeping its rectangular shape, so that the next brick could be poured. The moulded bricks were sun-dired, turned every few weeks, and by about 45 days were ready for use.

The abandonment of nomadism which was then clearly marked by the early clay huts with crude walls of rammed or kneaded clay built without any signs of deliberate planning, as seen from their remains at Hassuna in the North, was eventually followed by the invention of mould-made clay bricks extensively utilised in more elaborate building of the Halaf period. At Eridu in the South however, sun-dired clay bricks were already being used in the construction of temples and other buildings of considerable distinction, marking the development of Sumerian architecture, and the introduction of new building techniques. Fairly elaborate systems of bricklaying were evolved, and these found expression in the unique interplay of projecting piers and wall recesses designed to give the appearance of strength and stability. In fact, excavations reveal some interesting details of bond in brick building, featuring the insert of closers at corners and wall ends. aulus, Marcel J.

Two colours of bricks are found in ancient structures, red-brown and grey, sourced from different soils. Red-brown bricks, commonly used in monumental structures where many bricks were needed, were made of dirt from agricultural land outside the settlement. Grey bricks were made of the occupation debris excavated within the settlement itself. Red brick is often found with grey mortar, which was made either with settlement debris or by including ash.

This was clearly a deliberate choice by the builders, and gray mortar must have been thought to make a better bond. Indeed, modern Iraqi builders insist that grey bricks, made from settlement debris are stronger than those made from field soil. However, such claims do not seem to have been scientifically tested as of yet.

A unique advantage of mud bricks is their easiness. The 25 m x 5 m x 4 m high walls of the dig house at Tell Brak were built in six weeks, including the manufacture and drying of the bricks, by one master builder and four laborers. Also, mud bricks are durable so long as they are protected from water; the roof must be kept in repair, as well as the exterior plasterwork. However, mud brick production is at the whim of seasonal vicissitudes.

Rainy northern winters preclude drying, while droughts preclude mud production. Also, a crop failure can devastate brick production; Oates (1990) calculates 100 bricks require 1 about 1½ (60 kg) of straw. Thus, the nearly 1,000,000 bricks and their mortar of Naram-Sin's palace at Tell Brak would have required 13 sq km of cultivation.

When in Late Assyrian times trench-built foundations were replaced by platforms or rafts of mud-brick, the number of bricks used in the platform alone ran into millions. It is no wonder that the Assyrian king Ashurnasirpal 11(883-859 BC) brought in more than 47,000 deportees from newly conquered territorv for the construction of his new capital at Nirnrud. Nor is it implausible that the demand fo* straw for brick-making over five years. the period of construction of his North-west Palace, could have been met by more reliable crops in the Tigris valley. But outside this well-favoured region, on the borders of rain-fed agriculture, a problem undoubtedly existed. In 1957 we excavated a Roman barracks at Ain Sinu, some 95km west of Mosul, which had been built in the early years of the third century AD, obviously in haste and at a time when straw was not locally available, since there was virtually none in the bricks. Oates 1990, p 390-391)

Later, some mud bricks would be baked in a kiln for high durability. Baked bricks were produced in limited quantities due to the great expense of their production, as fuel of any sort was at a premium. In private dwellings, baked bricks were always limited to areas of maximum wear and tear like thresholds and areas where water was used. Until the Ur III era, even monumental architecture limited the use of baked bricks to thresholds, areas of water use, pavement and façades' revetment (and strengthening city-walls).

However, Ur-Nammu and his successors would use baked bricks in large quantities at the Ur temenos, as evidenced by the 2.4 meter thick encasing of baked brick used on the ziggurat (a primary reason for its relatively good preservation). Also, Shulgi and his successor Bur-Sin built royal tombs entirely of baked brick.

Riemchen Bricks

The first bricks were broad flat riemchen bricks. These were made by pouring the brick into a mould, then swiping away the excess mud for a flat top. The Sumerians understood the fundamental of bricklaying, implementing stretchers and headers and stacking bricks differently (or using differently sized bricks) at quoins.

Throughout the eras, the walls of private homes were typically two tiles deep.

Houses at the citadel in هه ولير Hawler in كوردستان Kurdistan العراق Iraq. Left: flat bricks in an irregular lay of stretchers and headers. Right: flat bricks with insouciant here-and-there alternating flat courses and herring-bone lays. Image © L M Clancy, 2010.

From the citadel in هه ولير Hawler in كوردستان Kurdistan العراق Iraq, to the left are flatly laid bricks and to the right is a highly irregular herringbone lay (scarcely is there an actual herringbone!). In the background is a Kurdish flag. Image © L M Clancy, 2010.

Plano-Convex Bricks

After a transitional period spanning the Early Dynastic I era, riemchen bricks disappeared completely and were replaced by slightly larger 20 x 30 centimeter plano-convex bricks. Plano-convex bricks were achieved by patting the excess mud at the top, forming a dome such that the brick resembled a loaf of bread. This top domed face often had the impression of a thumb, a fact whose function has been much discussed. While it has been suggested that they allowed the mortar to more readily adhere to the brick, this theory is unacceptable because the thumb mark was often so shallow and/or in a corner, where it would be of no use. Ethnographic evidence indicates the marks were to distinguish the products of one brick-maker from another. In modern العراق Iraq, the use of impressions on bricks prevents any person from claiming bricks that were not made for him.

This theory is further supported Ernest MacKay's findings at Kish of plano-convex bricks with even two thumb prints, and at the pillared hall were bricks with markings made using a stick or finger, the latter impressions also found by Edgar Banks at Adab (modern Bismaya). It should be no surprise that when the first monumental buildings arose in the ED II era, that the more quickly produceable plano-convex bricks became standard and that their enormous production required some sort of marking.

Plano-convex bricks' domed surface and irregular height precluded conventional bricklaying. They were typically laid in a herring-bone fashion: one course was laid on its side at a tilt, and the following course had an opposite tilt.

An intervening course of flatly laid bricks was ideally laid every two courses (though these sometimes appear to have been forgotten).

Like other Mesopotamians, the Sumerians constructd their buildings of mud bricks, shaped in a four-sided mould and dried in the sun. Up to the end of the Protoliteraete period, small rectangular bricks laid flat in horizontal courses (German, riemchen) seem to have been the rule. But, after a transitional period, covering the Early Dynastic I period, these disappeared completely and a new method of building was adopted. Bricks were now slightly larger and plano-convex in shape, having one rounded face often marked with the impression of a finger or thumb. They were laid 'on edge' like books on a shelf, succssive courses leaning sideways in opposite directions to create a herring-bone pattern (easily recognizable as a crieterion of the second and third Early Dynastic phases). (Lloyd, p 118)

This odd shape seems to have been achieved by rounding off each brick made by the wooden frame by hand, instead of striking off all the surplus mud to make a flat surface. These bricks were often laid in a distinctive herring-bone fashion, although they were also used in more conventional bondings of which the builders had a good understanding. Although these bricks are so distinctive and are found mostly in the Early Dynastic period, they are not an ideal type-fossil as they do not occur in the north and have recently been found in Agade contexts as well. (Crawford 1991, p 55)

Flat Quadratic Bricks

By the end of the Ur III dynasty, plano-convex bricks had been entirely replaced by large square bricks, 31-35 centimeters on their sides and 8-10 centimeters thick.

Plano-convex bricks had been used for a short period in Early Dynastic times, their size was 20 x 30 cm. Later on quadratic forms were mostly employed, 31-34 cm square, and 8-10 cm thick; the Assyrian building brick was somewhat larger (37-38 cm square, the thickness varying form 10 to 15 cm). In the building of houses warm bitumen (kupru) was originally used to cement the bricks together, later on gypsum was employed as mortar (gasssu).

A system of vertical drainpipes provided an outlet for showers and helped to airdry the walls wetted by the rain. The walls of private houses were thin, 1-2 tiles deep, provided with stucco, and hung with woven carpets, originally plaited rush mats; later they were decorated with durable enamelled (glazed) tiles; the floors were of stamp earth, only in places were there clay or stone floors. The outer wall faces might be enlivened by patterns of round disks, or by a saw-toothed front.