Carpentry 413 475 Detail of the wooden staircase in fig. 474, which had solid steps. Roman building 414 476 Longitudinal cross-section showing the position of the wooden staircase passing above the internal staircase of the shop. steps 26cm high and 32cm deep, plus the start of two others, with an incline in the region of 38 degrees. This sketch points to the existence of a staircase with solid steps identical in structure to the one at Herculaneum but slightly different in its dimensions since, though its incline is gentler, the height of the steps would have made them difficult to climb (figs 478, 479). The upper level is still marked by the support holes of the landing beams which occupied the total width of the corridor, 1.63m. Due to the collapse of the walls, the layout of the upper rooms is unknown. Another staircase in the House of the Faun, although no clue survives as to its upper wooden structure, has preserved six lower steps, made of lava and limestone tuff, a more comfortable 19 to 21cm high (the limestone is more worn down) and 29cm deep, equivalent to an incline of 35 degrees. The second category of staircases that can be identified is that of opentread stairs; this sort, to judge by the numerous traces of supports in the facings of masonry, was much more typical than staircases with solid steps. Two reasons for this are that this type takes up less space than the preceding one, thanks to the steep incline made possible by the openwork steps, and that it uses far fewer materials. Carpentry 415 Herculaneum again provides a perfect illustration, in a shop situated in the Eastern insula IIA at No.9 (the area dominating the Great Palaestra), which is also one of the best preserved in the city.12 Still visible (protected by glass plates admittedly only moderately efficient due to the greenhouse effect that they produce) are the shelf arrangements designed for holding amphorae, the floor of a mezzanine and the upper part of a flight of opentread stairs (fig. 480). The two lengths of string boards are pieces of wood 15cm wide and 4.5cm thick which still hold up four steps, 3cm thick and 19.5cm apart, giving a height to clear of 22.5cm. The absence of risers in this type of staircase makes it possible to create a steep incline— here it reaches 65 degrees (fig. 481). In addition, the floor is held up by joists measuring 9.5×8cm, supported on a beam 19×10cm. Finally, two doors, one above the other, each gave access to a back room, the one on the ground floor still containing the wooden uprights of a bed. In the houses and shops of Pompeii there are numerous traces left by opentread stairs. In the vast majority of cases they are located in the corner of a room, where a block of masonry supports a few steps, ending with a small landing from which rose, at a steep angle, the wooden flight of steps. The string, supported by the wall, leaves a rising mark, often accompanied, when the wall was rendered, by a painted band of the same colour as the 477 Position of the staircase built in a corridor of the House of the Faun at Pompeii, VI, 12, 2. Roman building 416 478 Preparatory marking, incised in the mortar, for a flight of wooden steps. 479 Cross-section lengthways along a corridor in the House of the Faun, showing the solid base of the staircase, Carpentry 417 the location and marking of the flight of wooden steps and the support level of the landing. basement, indicating the incline of the string (fig. 482). One of the staircases, in VI, 5, 8, has left a collection of support marks that is particularly complete, making it possible to reconstruct not only the access to the upper storey, but also the landing and the floor. It began on the right of a partition wall which it pierces by a door 1.98m high (established by the socket of the lintel), and then rose on an incline of 46 degrees to the upstairs floor, 3.1m above. The mark of the string in the masonry is from 30 to 35cm wide and ends with a short landing measuring only 48cm, while the passage opening, clearly visible in the interruption in the support between the floor and the landing, had an opening of 1.73m; its width, like that of the staircase, which goes directly from the ground without a masonry pedestal, remains unknown (fig. 483). The structure of the ceiling and the floor of the adjoining room is perfectly clear: firstly there is a thin socket trench for the ceiling laths that are 480 Overall view of the shop at Herculaneum situated in the Eastern Insula IIA, no. 9, with (at the back) a bedroom in which the steps up to a bed have survived. Roman building 418 481 Cross-section and lengthways section showing the surviving wooden structures and their arrangement. 482 The remains of a wooden staircase support with a masonry base. The decoration of the rendering followed the incline as far as the upper landing. Pompeii, IX, 1, 4. Carpentry 419 nailed under the joists, then the support holes for the joists, 22cm high, 12cm wide and spaced only 15 to 17cm apart. This density can be explained by the considerable weight of the upper floor, made up first of all of a flooring, then a bed of mortar holding the surface for walking on—in total it here reached 18 to 19cm. Finally, it is worth noting that the lower face of these walking surfaces could be given a sloping lath ceiling identical to the horizontal ceilings, to which it was possible to apply a painted rendering, as can be found at the House of the Iliac Chapel (I,6,4) on the via dell’Abbondanza.13 3 Roof timbering As with all other wooden structures, the remains of roof timbering are unfortunately few. Even at Herculaneum and Pompeii there are scarcely any, except for traces of supports and sockets usually from roofs of modest dimensions where the solutions to the problem of roofing were fairly rudimentary (fig. 484). Of the methods used to cover the great monuments there remains absolutely nothing;14 the last ancient building which preserved its roof timbers throughout its history was the basilica of St-Paul’s-outside-the-Walls, built between 384 and 403. Unfortunately, these roof timbers were totally destroyed by a fire in 1823. It is thus useful to turn to the literary and iconographic sources, which are equally few in number, and to the remains of the supports left in the monuments. Though Vitruvius tells us at length about the different species of wood used in roof timbering (II, 9), he is hardly loquacious on their method of arrangement and treats us only to a very brief passage (IV, 2). In a few lines, he outlines carpentry of a wide span, de majora spatia, in which can be identi Roman building 420 483 The remains of a support for a wooden staircase, its passage opening and the upper floor, at Pompeii (VI, 5, 8 and 20). fied the truss (see below), and of more modest spans, commoda, simply resting on the upright pieces. In the face of such reticence it would be useful to be able to turn to the texts of estimates describing an official order for a monument or other architectural work. However, these documents, common Carpentry 421 484 Excavation of the peristyle of the House of Cuspius Pansa (I, 6, 1), revealing the roof that collapsed on to the lapilli. (Photo: V.Spinazzola.) among the Greeks who simply carved them in marble, are totally lacking for the Romans who wrote them on parchment, though there is, admittedly, the detailed estimate concerning the erection of a modest porch in front of the Temple of Serapis at Pozzuoli.15 The Roman pictorial record, as already seen, is rich in scenes of building sites and representations of machines and tools, but it fails to show the construction of roof timbers. One of the only sources of illustration of a large-scale wooden structure is Trajan’s Column, Roman building 422 485 Etruscan tomb at Cerveteri showing the ridge beam supporting the two slopes of the roof and, on the tympanum, the jointing of the pieces forming timber framing on the façade; c. 500 BC. which shows the bridge built on the Danube by Apollodoros of Damascus. By contrast, models of roof timbering on a large scale appear very often inside Etruscan hypogea, cut into the rock. The rooms of these funerary monuments invariably represented the house of the living, and the choice of carving these spaces into the tufa made it possible to reproduce the details of the interior of buildings with remarkable accuracy. A visit to the Banditaccia necropolis, near Cerveteri (Caere), is of great interest in this regard, as it provides several stages in the evolution of roofing techniques (fig. 485). One of the oldest forms of roofing is a simple support of posts on a roof-ridge, itself resting on the top of the wall of each façade. This hut form exists in the tombs of the seventh century called ‘hut tombs’, resembling on the inside a tent space, produced by the two slopes of the roof (sometimes called a ‘gable roof’). Up to the third century BC roofs can be found with this same profile, but very much lowered, often even consisting of just a ceiling and joists.16 A steeply pitched roof reappears occasionally, as Carpentry 423 486 A reconstruction in section of the Naval Arsenal, built by Philo in the fourth century BC in the port of Piraeus.