Proceedings of the First International Congress on Construction History, Madrid, 20th-24th January 2003, ed. S. Huerta, Madrid: I. Juan de Herrera, SEdHC, ETSAM, A. E. Benvenuto, COAM, F. Dragados, 2003.
Wood structures in traditional random rubble wall constructions in Cagliari.
Marco Cadinu
Recent research on the residential buildings in Cagliari from late the middle ages to the first part of the 20th century, is providing more information about wall construction as we!1 as more general construction techniques. This research allows to distinguish building methods, the materials used, and the architectural models though the different periods.' One section of the present study, designed to provide a preliminary identification of vertical structures limited to non-monumental buildings, has shed some light on the quality and nature of wall construction. The most recurrent waJl typology in the row houses and in the other buildings is composed of random rubb]e and lean lime. B]ocks of tufo stone are used only for door and window frames as well as quoining. This kind of wa]] is very simple, often made with the help of sustaining structures to contain and press the ]ayers of these materials; they range from around 42-58 centimetres.2 The static properties of these walls is mediocre because they are heavy and not very resistant to tensile and shearing stress; they were best used for one or two-floor buildings, although sometimes they can be found in four or five-floor buildings. In the present stlldy we have focllsed our attention on the taller buildings.' We have observed in the wall sections the interesting presence of horizontal juniper wood trunks. In this area of research, wood in the walls had previollsly been defined as tie-beams used to repair damaged wal1s. On the contrary, evidence Figure 1 has been found that this wood represents an essential We can see the end of wal1-plate at every tloor also in four component of the original wa!1s. or five-floor building s 454 M. Cadinu
The trunks were attached one to another to form a houses, it was common to use timher-frames with continuous transversal and Jongitudinal structure brick infill for partition walls. In the poorest buiJdings around the walls, making the random rubble wood was often used for lintels of doors and construction more resistant and t1exible: this hidden windows. In one instance the use of big wood beams structure is also connected to the tloor-joists. Moreover, has been documented for building the bearing sometimes we have found the presence of vertical structure wal! of the stairs in a four t100r building. wooden eJements. The typical scarf-joint is the edge- Short juniper woods were used as normal laths for halfed with a big iron pego The end of the wall-plate roofs. We found it also in planking (instead of often comes out of the far,;ade, with its wooden punch. tloorboards) or structures of stairs (Cadinu and It should be noted that wood structures had not Zanini, 1996.53). Other uses were possible. as single previously been found in Sardinia even if, in these pieces inside normal random rubble wall or as roofs
Figure 2 Figure 4 A couple of wooden tie-rod used to repair damaged walls. The floor-joist structure is connected with the juniper wood (Cagliari, Marina, Scalette di Santa Teresa) trunks inside the wal1
Figure 3 Figure 5 This detail shows a simple edge-halved joint with an iron A long wall-plate in juniper attached at the comer of the wall peg used to connect long series of trunks inside the wall. A and partially rebuilt outside the wall (a second one was similar solution is used for the corners (Cagliari. Marina, found inside the wall in the same position. Cagliari, Marina, Piazza Dettori) Piazza Dettori) - -
Wood structures in traditional randorn rubble wall constructions in Cagliari 455
Figures 6 and 7 A continuous structure of juniper wood trunks found inside a randorn rubble wall in a four tloors building (Cagliari, Castello, Via Larnarrnora)
Figure 8 Figure 9 The bearing structure of the stairs is built with wooden Irregular verticaJ wood eJernent in support of a brick bearns (Cagliari, Castello, Via Larnarrnora) partition wall
of a stone drain channel 55 centimetres of clear span.4 age period of the buiJding.6 This kind 01' structure is In order to reinforce walls, arches or stairs the use of very simple, no tension brace was used. Up until now single juniper woods is permitted in a contract of no sophisticated techniques of the fachwerk building 1786 were is written they may work «~o. . putting tradition have been 1'ound. inside some juniper wood to best connect them . . . ».5 Ancient documents do not report information about Similar wood structures with wall construction wooden houses even jf it was observed that such a ha ve been previously reported in medieval houses in type was present in some Sardinian towns, Parma and Pisa, the latter being the founder of particularly in Sassari. A building reguJation 01' CagJiari in the 13th century. The analysis of so me 1294-] 316 describes the form of the front cutaway on middJe-age houses in Pisa have shed some light on the public street, giving the sizes 01' projecting joists the mixed nature of the walls containing a whole for each tloor. This kind 01'section is very common in wood structure, that it possible to date to the middle- wooden buildings with brick or adobe infilI.7 456 M. Cadinu
lt can be hypothesised that the wood building from 3,80 to 5,40 meters of length, with diameters tradition common in the middle ages, and later between 16 and 32 centimetres. Nowadays in nature replaced by stone construction, intluenced stone trunks of these dimensions are quite rare and can be buildings in Sardinia in later centuries. Middle age 1'ound only in parks and protected arcas. «Statuti» in Sassari encourage owners to rebuild old According to our assessment of pre-industrial houses with new techniques of stone and lime (<
JlIN1PER woon
Juniper wood, uscd also for roof trusses and tloor- joists up unlil the beginning 01'the twentieth ccntury, can be 1'ound nowadays only in bushes. In traditional Figure 1() buildings juniper has been found in trunk ranging A limber-frame with brick infill ~~
Wood structures in traditional random rubble wal! constructions in Cagliari 457
Figure II Figure 12 The front view of a square hole built to drain waters by a A drain pipe made with piled cotto elements inside the walls. bucket directly from the highest tloors (Cagliari, Marina, This pipes drained the water to a underground family tan k Piazza Oettori) that has been dug under each building (Cagliari, Marina, Piazza Oettori) irregular structure that often causes performance complex, particuJarly in the context of restructuring decrements, the average resistance ofjuniper wood can and renovation interventions. be estimated to be more or less double to the resistance Rain waters were generally collected by drain of a pine wood. The characteristic of its resin gives the pipes made with piled cotto elements inside the walls. juniper wood its typical scent and protects it from This pipes drained the water to a underground family fungi, woodworm and white ant. Only under severe tan k that had been dug under each building. Waters and persistent conditions of humidity a partial were drained directly from the highest tloors inside deterioration can be found. Thus, juniper durabiJity the wall through a hole as large as a bucket. appears to be excellent. 11 From the kitchen a t1ue inside the wall typically took the smoke to the top of the building but often only to the front. The last example of this system, Inside the walls. forbidden only after the building regulations in 1840, can be observed in an old house built after the end of In the traditional houses in Cagliari other elements the XVII century in Cagliari, at the comer of Santa inside the house waJls make the analyses more Croce church.12 The squared holes inside the walls -- --
458 M. Cadinu
Figure 13 A different kind of drain pipe made with piled cotto Figure 14 elements inside his own squared hole built inside the wall In the front views of this house, built after the end of the (Cagliari, Castello, Via Lamarmora) XVII century in Cagliari at the comer of Santa Croce church, we can see the end of wall-plate at every floor and on the left, from kitchens, the old front chimneys. This system was forbidden after the building regulations of XIX were often closed on the internal side by brick infil! century built between little beams.
settlement context) has been conducted by the Prof. NOTES Antonello Sanna and Prof. Adolfo Cesare Dell' Acqua at the Universities of Cagliari and Bologna, respectively. 1. This research, conducted At the Dipartimento di 2. Some researches in the Archivio Comunale di Cagliari Architettura dell'Universita degli Studi di Cagliari, has permitted to find so me description of this kind of wall, the goal to compile an handbook for the restoration of like the one in a document written in a contract of 1786 Cagliari, with the metods of the «Manuale del for a new part of the City's Palazzo Civico: «La Recupero», (Marconi et aL 1989). ]n the city of Cagliari costruzione della muragJia verra formata con cantoni di many historical building regulations made the bui ldings pietra tramezzaria o mattoni per riguardo al1a facciata different from the rest of its countryside area, where the angoli, spalle volte, fasce l'intemo pero della muraglia most tecniques use the adobe walL A previous study in si potra costruire in pietra ordinaria. . . e nel scagliare this area (Tradition of construction within the national la suddetta muraglia dovranno battersi con martello a territory: continuity and evolution of building forza le pietre ben nuotate in calcina, e serrate.», see techniques for the environmental safeguard of Melis (1997-98. 93-94). ~-
~--
Wood structures in traditional random rubble wall constructions in Cagliari 459
8. üld houses were built in stone and adobe, «de petra et de lutU», see again in Cadinu (2001,152). 9. (Manca 1969). More observations about names and mcanings in Cadinu (2001, 182-190), «Glossario dei termini urbanistici ed edilizi». 10. Examples from Manzaneda de Torío (León) and Calahorra de Boedo (Palencia) look very interesting and show closing methods common to distant areas that wilI be useful to study in the future. See Ponga Mayo and Rodríguez Rodríguez (2000. 135; 14]). ] l. Neither laboratory tests about the static properties of juniper woods (juniperus phoenicca but also juniperus oxycedrus oxycedrus and juniperus oxycedrus macroearpa) have ever been conducted, nor tests for the Figure 15 compilation of a dendrocrono]ogical list; we have Two old front chimneys with their outward sides brick infill planned a research project on this topie. (on the right) or cotto ti]e (on the left) ]2. The neighbours at the highest tloors had to allow the building of a new chimney to the top of the building, see in «Archivio Comunale di Cagliari, Atti Amministrativi e Governativi, Regie Patenti, Torino I 1-4-1840, Titolo 3. Some building yards of restoration of old houses in VI, art. 47», also in Cadinu (1996. 97). Cagliari Castello and Marina, directed by myself, have provided exemplars presented in this meeting. 4. The possibility of finding in nature big juniper curved trunks allowed builders in the past to use them for two REFERENCE LIST pitches roofs. In the past they where described as false ] roof trusses, even if they are simple beams. Cadinu, Marco. 996. Regolamenti edilizi a Cagliari nella 5. «... mettendovi gualche legno di ginepro per ligarli prima meta del XIX secolo. Storia deIl'Urbanistica. maggiormente. . . », see in Melis (1997-98.96). Annuario Nazionale di Storia deIla Citta e del Territorio. 6. (Redi 1996, 89-100). In Parma some studies have I regolamenti edilizi. Nuova Serie. 1/1995. 90-102. reported the presence of some middle age wooden Roma: Kappa. houses with their survived wood parts inside the walIs, Cadinu, Marco; Zanini, Laura. 1996. Urbanistiea ed edilizia see Doglioni, Merli and Storchi (1987, 505-5]6); nella Cagliari medieva]e: il borgo di Villanova e le sue ¡¡ regarding houses in Pisa see Redi (1989, 107-117; case. In Case e torri medievali. 1. Atti del Convegno di 146-151) and the old good classic Lupi (1901). Studi «La citta e le case. Tessuti urbani, domus e ease- 7. From the building regu]ations of Sassari, Libro 1, torri neIl'ltalia Comunale (secc. XI-XV»>, Citta della ] XXXVIII: « . . . et supra alcuna via gui aet esser de Pieve, 1-12 dicembre 1992. Edited by E. De Minicis palmos XV, oVer minus, non se fathat solaiu in alcuna and E. Guidoni. 49-58. Roma: Kappa. domo posta testa ad ecussa via, su gualc solaiu essat Cadinu, Marco. 2001. Urbanistica medievale in Sardegna. foras dessu muru su plus palmos iij, et cio in su primu Roma: Bonsignori. solaiu, et ecussu solaiu gasi postu testa a bia siat altu DogJioni, F.; C. MerJi and S. Storchi. ]987. Prime palmos XIV. Et de cussa altithia siat [su tectuJ over osservazioni sul ritrovamento di parti superstiti di grunda de pscatuna domo posta testa a via et non essat costruzioni a struttura Jignea in edifici del centro storico cussa grunda over tectu foras dessu muru plus de cussu di Parma. Archeologia Medievale. XIV 505-516. gui est naratu dessu solaiu, et si alcunu aet al¡;:are sa Lupi, C. ]901. La casa pisana e i suoi annessi nel medioevo. domo sua, gui ait esser testa a via publica in altithia de Arehivio Sto rico Italiano. V. XXVIII; XXXI. duos solaios, su secundu solaiu non essat foras de su Manca, Ciro. 1969. 11 libro dei conti di Miguel (:a-ROJ'ira, muru de cussa domo vltra palmos IV. Et si alcunu aet Padova: Cedam. bollet al¡;:are sa domo sua da ve duos solaios in susu, in Marconi, Paolo et al. 1989. Malluale del Recupero del ¡;:ascatunu solaiu pothat essire palmos V.». Comlllle di Roma. Roma: DEI. A drawing of the cutaway of this houses with projecting joists MeJis, Patrizia. 1997-98. Carte di costruire a Cagliari- for each jloor was compared with others coming from the Marina. Analisi dell'edilizia storiea. Tesi di Laurea. fackwerk areas (Cadinu 2001, 116). Regarding projecting Relatore Prof. Ing. Antonello Sanna. Universita degli joists in fachwerk buildings see Walbe (1979. 9). Studi di Cagliari. Dipartimento di Architettura. 460 M. Cadinu
Ponga Mayo Juan Carlos; Araceli Rodríguez Rodríguez. domus e case-torri nell'ltalia Comunale (seec. Xl-XV)>>, 2000. Arquitectura popular en las comarcas de Castilla y Citta della Pieve, 11-12 dicembre 1992. Edited by E. De León. Junta de Castilla y León. Minicis and E. Guidoni. 89-100. Roma: Kappa. Redi, Fabio. 1989. Edilizia medievale in Toscana, Firenze Solmi, Arrigo. 1908. Un nuovo documento per la storia di Redi, Fabio. 1996. Reperti archeologici del! 'edilizia GugJielmo di Cagliari e del]' Arborea. Arehivio Storico medieva1e pisana a confronto con la documentazione Sardo. Vol. IV. 1. archivistica coeva. In Case e torri medievali. l. Atti delll Wa1be, Heinrich 1979. Das hessiseh-friinkische Fachwerk. Convegno di Studi «La citta e le case. Tessuti urbani, GieBen: Brüh1scher Verlag.