WOOD CONSERVATION IN HISTORICAL BUILDINGS The case of brazilian woods

Extended Abstract

Maria Francisca de Jesus Casimiro Sales Barreto

Thesis to obtain the Master of Science Degree in

Supervisor: Professor Doutor José Maria da Cunha Rego Lobo de Carvalho Supervisor: Professora Doutora Ângela do Vale

May 2017

Introduction

This article summarises the thesis carried out within the scope of the master degree in architecture, at Intituto Superior Técnico. The research process is result of an exchange semester in combined with personal interest in the theme of brazilian woods, as well the rehabilitation of historical buildings.

During the colonial period of Brazil (XVI-XIX), imported high quality Brazilian hardwoods for textile dyeing, shipbuilding, civil construction and decorative arts. These woods had high durability and strength and, despite the numerous references about them exploitation and trade on the other side of the Atlantic, the use of Brazilian wood in Portugal has not been much studied. There are some sporadic references to the alleged use of "brazilian wood" in noble buildings (palaces or monasteries), but their verification and documentation remains to be done. The present study intends to contribute to the study of this theme, with the following objectives: a) To understand the role of brazilian woods in the portuguese colonial period; b) To frame the tradition of wood construction in Portugal; c) Identify buildings in Portugal that used brazilian woods from colonial period; d) Selec a case study; e) Make brief considerations on the conservation and intervention of wood elements in historic buildings.

Brazilian historical woods

Brazil's wood trade is immediately associated with the botanical specie pau brasil [Caesalpinia echinata Lam], which has historically been the most exploited due to its high commercial value for fabric dyeing. However, pau brasil was only one of several brazilian tree species exploited by the Portuguese in the colonial period (OLIVEIRA, 2003). At this time, commercialized woods were classified in three groups by naval carpenters: soft woods, hard woods and "royal woods". The “royal woods” were known as the species protected by law, where their exploitation and trade was exclusive to the Portuguese crown (GONZAGA, 2006; 39). According to the chroniclers of the time, these woods were mainly used in shipbuilding given their incorruptible quality. Examples of these species are: cedar and vinatic (Fig. 1). Numerous documents from the Arquivo Histórico Ultramarino (AHU), in , confirm the shipment of wood to the Royal Navy Arsenal of Lisbon and also, for the construction of royal buildings; but there´s no specifications of which ones. Through documentary research in the main national archives and by analysis of historical buildings constructed in the mentioned period, it was found that most of these buildings suffered a fire or repair in which the original woods were replaced. The existent documents about these buildings were very poor in terms of information about structural materials. Only the decorative elements, such as the and stucco, are the most documented.

Figure 1: Watercoler representation from 1742 of tree species: cedar (28) and vinatic (29). Wood in Portugal

Wood has always been a present material in the Portuguese architecture, used in the execution of structures in pavements, coverings and foundations. The Pombaline period, after the earthquake in 1755, was probably the time were wood was being more intensively used in construction in Portugal (APPLETON, 2003). Applied in the mixed system of wood structure and stone, the "pombaline cage" consisted in a reticulated wall of high flexibility and energy dissipation capacity with anti-seismic characteristics (Fig. 2). In Portugal, the most used species in construction were mainly native, with differences according to the region of the country. Unlike Brazilian historians seem to suggest, the use of exotic wood in the post-earthquake civil construction was not significant. In the Pombaline construction there are essentially wood of autochthonous species, such as: chestnut, cork oak, evergreen oak and pine. When imported woods were used, the species found were: scots pine and pitch-pine, from and North America, respectively (APPLETON, 2003). In this study was found exoctic wood in only one Pombaline building. The exoctic wood was applied to the steps of the main staircase, however, without certainty of the species or origin (APPLETON, 2009). Exotic woods in Portugal are more commonly found inside churches or applied in carpentry works such as chairs, carving and tribunes (SMITH, 1962). In an attempt to deepen this theme and try to confirm the use of exotic wood, imported in the colonial period of Brazil, several buildings of the period were studied trying to find a case study.

Fig. 2: Typical wall structure of a pombalino building.

Case study - Pombal Palace

History of the Pombal Palace

The case study of Palácio Pombal is located at 79 Rua do Século, Bairro Alto; one of the first planned neighborhood of the city of Lisbon that, due to the good quality of the construction of its buildings, survived without great damages to Earthquake of 1755. Pombal Palace or Carvalhos's Palace is a building from the second half of the 16th century, where Sebastião José de Carvalho e Melo (1699-1782) was born and lived; also known as the Marquis of Pombal; Secretary of the State of Internal Affairs of the Kingdom between 1750-1777. According to Irisalva Moita (1968: 49) this building was the favorite residence of the Marquis of Pombal, which explains his constant investment on it and could justify the use of Noble in its construction, during a period of great importing activity from Brazil, as previously mentioned. Also temporarily lived in this palace, two important traders of the colonial period - Gerard De Visme and Jâcome Ratton - related with the Brazilian wood trade and the exotic tree plantation (LUCKHURST, 2014). The importation of brazilian wood it would not be difficult for these two merchants, however, no references were found about reformulations in the palace using Brazilian hardwoods in the period in which they inhabited the palace. At the beginning of the 20th century, the palace is successive occupied by several institutions that contributed to the degradation of the building. In 1968, it is acquired by the Municipality of Lisbon (CML) that executed some reforms of conservation and restoration. Later in 1993, was classified as Public Interest Monument. Since 2009, the building has been shared between the Municipality Galleries1 of Lisbon and the Center of Art and Research - Carpe Diem, that use the space and guarantee its maintenance (BALSINHA, 2011).

Figure 3: Exhibition in the Blue room of Pombal Palace.

1 The Municipality Galleries of Lisbon it is a department of EGEAC that is in charge of the management of exhibition spaces of the CML.

Woods of Pombal Palace

When visiting the interior of the Pombal Palace it is possible to verify the presence of various wooden elements used in structure and coverings. At first sight, different species of wood were observed, in their tonality and design of the veins and dimension (fig.4 and 5).

Figure 4: Wooden pavement at the ground floor.

Figure 5: Wooden pavement at the first floor. In order to confirm that the Pombal Palace preserves in its interior exotic wood imported from Brazil during the colonial period, it was request at the General Direction of Cultural Heritage the support of ‘José de Figueiredo’ Laboratory to collect an analyse samples of wood in the palace. It was sought to remove samples of different constructive elements for an overall analysis of the palace's woods. The observation of the morphological characteristics of the wood is what allows its identification. A magnifying glass is used to observe the main anatomical elements of the wood, and for the visualization of all the elements, even the smallest ones, it is necessary the microscopic observation. However, it is not always easy the identification of the species (ESTEVES, 2001). The native woods, most common in the construction in Portugal, were easily identified as to the genus (Pinus, Quercus, Castanea and Taxus); As opposed to exotic woods, of which only a few have been identified (Bowdichia, Carya and Hymenaea). Nevertheless, two genus corresponded to species of some "royal woods" trade by the Portuguese: sucupira [Bowdichia sp.] and jatobá [Hymenaea sp.]. For a more accurate taxonomic identification it will be necessary to compare with other collections of wood, existing in the other national libraries, or a molecular analysis. It should be emphasized that these samples also revealed the advanced state of degradation of some wood elements, in particular of the autochthonous species, which confirms the superior quality characteristics of the exotic woods. The existence of exotic wood in the Pombal Palace raises interesting considerations regarding its conservation, namely by its difficult substitution for other woods of the same species or characteristics, when in poor state of conservation. Despite its physical condition, its value as a testimony to the Portuguese colonial past and the history of construction is also an important factor to consider in rehabilitation (OLIVEIRA, 2003). In this sense, rehabilitation interventions of historic timber structures should consider a specific methodology that includes, in particular, a rigorous architectural survey, identification and exhaustive characterization of the materials and a historical and documentary framework that justifies the project options, namely the preservation of original elements as a contribution to the material authenticity of the buildings.

Final considerations

The knowledge of the species and the characteristics of the woods is fundamental for better and justified interventions and contributes important knowledge to the history of science and construction. As such, intervention criteria are required in historic buildings that contemplate a complete study of pre-existing woods. Although exotic woods were found in the Pombal Palace, possibly coming from Brazil; In general, the use of Brazilian wood in Portugal seems to have been insignificant; However, it is important to deepen this study and understand its real use in shipbuilding and civil construction. As such, the analysis of construction documents of the main national monuments (palaces, churches and convents) of the eighteenth and nineteenth centuries, may be a way of perceiving the materials used in their construction. Finally, the exact identification of some woods of the Pombal Palace remained to be determined, since due to the scarcity of time and means it was not possible to identify all species. It would be interesting to conclude this identification using the wood librarys of the Superior Agronomy Institute (ISA), the Tropical Botanical Garden (JTB), the Lisbon Academy of Sciences and the National Museum of Ancient Art (MNAA).

Bibliography

APPLETON, João, 2003. Reabilitação de Edifícios Antigos - Patologias e Tecnologias de Intervenção, Edições Orion, Lisboa.

APPLETON, João G., DOMINGOS, Isabel., 2009. Biografia de um Pombalino: um caso de reabilitação na Baixa de Lisboa, 1ª edição, Edições Orion, Lisboa.

BALSINHA, Ângela Cristina Faustino, 2014. Património Arquitetónico e Arte Contemporânea: o caso do Carpe Diem, em Lisboa. Dissertação para obtenção do grau de Mestre em Arquitetura apresentada ao Instituto Superior Técnico, Lisboa, Portugal.

GONZAGA, Armando Luiz, 2006. : Uso e conservação, Programa Monumenta - cadernos técnicos, nº6, DF: IPHAN/MONUMENTA, Brasília.

LUCKHURST, Gerald, 2014. Monserrate, an English Landscape Garden in Portugal (1790- 1901) volume 1, A dissertation submited to the University of Bristol in accordance with the requirements of the degree of Doctor of Philosophy in the Faculty of Arts, Department of Archaeology and Anthropology.

MOITA, Irisalva, 1968. O Palácio dos Carvalhos à Rua Formosa, Revista Municipal, nº118/119, pp. 48-88.

OLIVEIRA, Mário Mendonça de, 2003. “Um estudo documental sobre da Bahia usadas no passado em Portugal e no Brasil”, III ENCORE - Encontro sobre conservação e reabilitação de edifícios, LNEC, Lisboa, pp. 439-448.

SMITH, Robert C., 1962, A Talha em Portugal, Livros Horizonte, Lisboa.

Pictures Credits

Figure 1: Watercoler representation from 1742 of tree species: cedar (28) and vinatic (29). AHU – Catálogo de Castro e Almeida. Bahia. Col. cart. - icon., Doc. 13768-13815. Relação das madeiras que se encontram nas matas do termo da vila da Cachoeira, acompanhada de quarenta e seis estampas aguareladas, feita pelo juíz de fora, Joaquim de Amorim Castro. 1790.

Fig. 2: Typical wall structure of a pombalino building. Font: APPLETON, 2009: 28.

Fig. 3: Exhibition in the Blue room of Pombal Palace. Font: carpediem.pt