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Traditional architecture is the result of collective experience in the optimum use of available materials in a given location and adapted to specific conditions and needs. Although forms and groups also depend on other cultural and social issues, the constructive techniques used depend mostly on geographical conditioning factors such as altitude, hydrography, lithology, climate, etc. This text aims to analyse the possible relationships among the multiple variants and specific geographical conditioning factors of each location; in turn, this should provide an understanding of the reasons motivating or reducing their use and the mechanisms adapting these techniques to these conditioning factors. The analysis cross-referenced GIS systems from a database compiling information on 1160 half-timbered walls with a series of themed maps containing information on geographical factors. The conclusions reached show that a single technique adapts to different geographical conditioning factors, giving rise to a wide range of solutions which can provide greater durability and improved habitability. This capacity to adapt to the location is a lesson in sustainability that can be applied at present and is above all part of the intrinsic wealth and value of traditional architecture. [ABSTRACT FROM AUTHOR]

Present results provided new information on the practice of removing iron from waterlogged wood using chelating agents. Two series of samples were selected: small waterlogged wood samples of Quercus spp., Pinus sylvestris L. and Pinus pinaster Aiton, and a portion from the dismantled shipwreck Huguangjiao I. Iron extractions were carried out using disodium ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA). Samples were characterized by environmental scanning electron microscopy coupled with dispersive energy spectrometry, micro-Raman spectroscopy, atomic absorption spectroscopy, Fourier transform infrared spectroscopy and dynamic mechanical analysis (DMA), the latter used to evaluate viscoelastic properties. The extraction efficiency of both products was good, although it depended on the wood state of preservation, being higher in more decayed material. Still, the extraction procedures induced a limited effect on the decayed wood tissue, affecting both cell wall chemical composition and physical characteristics. Moreover, a significant difference existed between the two agents. In decayed hardwoods, they had an impact on both E' (decrease) and tanδ (increase), mostly apparent for DTPA. The difference between DTPA and EDTA was also more evident when the frequency was varied in DMA tests. In contrast, the well-preserved softwood was not affected by the considered treatments. [ABSTRACT FROM AUTHOR]

St Francis of Assisi Church is an historic religious building in the centre of Valletta, Malta's capital. Through analysis of the roof structure we have determined the timber species used in its construction, their state of conservation and the date of different building phases and maintenance work. The study provides an historical and cultural framework for the entire building. Apart from identifying the type of timber and typically English way of construction, dendrochronological dating has revealed two precise phases of intensive restoration, dating to 1681 and 1876, respectively. For both periods, the timber's provenance points to the Eastern Alps, based on dendrochronological master chronologies of European larch (Larix decidua). Furthermore, a single Norway spruce (Picea abies) board from the vault was dated to 1684. This church is a typical example of Maltese culture, intermingled with other cultures that have resulted in a very particular architectural-work. [ABSTRACT FROM AUTHOR]

The weathering of wood through abiotic factors has been extensively studied. Much less research has been conducted on the influence of biotic factors on wood in exterior use that is not in ground contact, i.e. use class 3. There is especially a lack of research concerning the influence of the presence of bacterial and fungal communities on the weathering process of wood. The project aim is to identify any synergistic effects between biotic factors such as bacteria (Actinomycetes and Eubacteria) and fungi (Basidiomycota and Ascomycota) and abiotic factors such as light, temperature and moisture on the weathering of wood surfaces in use class 3. This paper presents results such as the amount of colony forming units (CFU), environmental scanning electron microscope analysis, colour changes and moisture content (MC) from preliminary experiments where wood surfaces were either naturally or artificially weathered. In order to study the interactions of fungi and bacteria on wood during the weathering process, the presence of microorganisms on natural weathered oak and Douglas fir surfaces had to be validated first. With the help of a surface contact test, microorganisms on the wood surfaces were transferred to agar plates and consequently incubated so that they could grow in appropriate conditions. Once the microbiological colonies had developed sufficiently, they were separated by selecting sections from the colonies and replated on fresh agar. A microcosm scale experiment, meaning the transfer of one specific bacteria and one fungi together in one petri dish, was carried out. This trial revealed that certain bacteria have an influence on the growth rate of certain fungi. In addition, an artificial weathering test was carried out in a QUV, which allows the degradation of samples using specific and known abiotic degrading parameters. The observation of the artificial weathered wood samples revealed that microorganisms are most definitely present in the QUV test apparatus and may influence the test results. [ABSTRACT FROM AUTHOR]

The triangular truss is the most typical structural frame of Italian historic roofs. Mostly, but not exclusively, used to transfer vertical loads to walls, it has been developed during centuries into different geometrical compositions by using also different wood species and materials. The aim of this article is to describe the most typical features of the Italitan trusses and the survey procedures by using practical examples taken from hundreds of inspected structures. The complete assessment of a roof structure is an interdisciplinary activity, while this article is intended to present the point of view of the wood technologist, only partially considering the structural aspects. The survey is performed on the basis of a step-by-step procedure, with increasing levels of analysis: starting from a general analysis of the structure as a whole to the analysis of the single members and connections, gaining so far more and more detailed information, which can explain the results of the previous level of analysis. The most common pathologies occurring on timber trusses and structures are also described. Finally, before general conclusions, a quick case study, based on a roof structure from the beginning of 19th century, is shown, presenting the principal results obtained. [ABSTRACT FROM AUTHOR]

Timber structures can be degraded during their life both by structural problems and by biological degradation factors like fungi and insects. The occurrence of those biodegradation agents could lead to a loss of their structural integrity, in the absence of appropriate maintenance. An early assessment of the decay is even more important when the wooden structures are part of historical buildings, in the interest of conservation of cultural heritage. This article presents an application of microwave reflectometry for the in situ evaluation of timber structures. The measurement system allows detecting anomalies inside the material in a non-destructive and non-invasive manner. The reflection coefficient is measured by means of a vector network analyzer (VNA) using a double-ridge antenna which transmits the continuous-wave (CW) microwave signal and receives the signal reflected by the material under investigation. Measurements on laboratory models demonstrated the feasibility of the method. Results obtained on timber beam sections, compared with the findings of traditional investigation methodologies, demonstrate the potentiality of microwave reflectometry, suggesting its possible usefulness during the diagnostic phase as a non-invasive tool for preliminary screening. [ABSTRACT FROM AUTHOR]

Timber structures can be degraded during their life both by structural problems and by biological degradation factors like fungi, and insects. The occurrence of those biodegradation agents could lead to a loss of their structural integrity, in the absence of appropriate maintenance. An early assessment of the decay is even more important when the wooden structures are part of historical buildings, in the interest of conservation of cultural heritage. This work presents an application of microwave reflectometry for the in situ evaluation of timber structures. The measurement system allows detecting anomalies inside the material in a non-destructive and non-invasive manner. The reflection coefficient is measured by means of a vector network analyzer (VNA) using a double-ridge antenna, which transmits the continuous-wave microwave signal and receives the signal reflected by the material under investigation. Measurements on laboratory models demonstrated the feasibility of the method. Results obtained on timber beam sections, compared with the findings of traditional investigation methodologies, demonstrate the potentiality of microwave reflectometry, suggesting its possible usefulness during the diagnostic phase as a non-invasive tool for preliminary screening. [ABSTRACT FROM PUBLISHER]

Jack arch floors are structures made of timber joists, with round or squared section, and segmental vaults either made of flat tiles or poured plaster conglomerate. They are especially diffused along the Mediterranean coast of Spain and can be considered as a main feature of the historical and vernacular architecture of the area. In order to assess and grade these structures several Spanish standards have been considered; however, even if the information contained is useful the Italian standard for the on-site diagnosis UNI 11119 of 2004 has been preferred. The method described in this standard leads the assessment through the grading of each and every timber element and the assignation of bearing properties that are essential for the consolidation project. This article will expose three examples of jack arch floors of the Valencian Community graded using the Italian standard and the conservation issues that arise from the results. [ABSTRACT FROM PUBLISHER]

In the scope of European Cooperation in Science and Technology–Wood Science for Conservation of Cultural Heritage (COST IE0601–WoodCultHer) (available athttp://www.woodculther.org) it was agreed to produce Guidelines for the Assessment of Historic Timber Structures, covering the principles and possible approaches for the safety assessment of old timber structures of historical relevance that could be used as the basis for possible European Standards, as discussed with CEN/TC346 (Conservation of Cultural Heritage). This approach was targeted at all those concerned with the conservation of heritage buildings. These guidelines should also help decision-making regarding the need for immediate safety measures. The aim is to guarantee that inspection and assessment measures provide the necessary data for historical analysis, structural safety assessment, and planning of intervention works, while having minimal impact on the building fabric (the original materials, structural systems, and techniques).This article provides information on the criteria to be used in the assessment of load-bearing timber structures in heritage buildings. It covers the preliminary assessment (desk survey, preliminary visual survey, measured survey, structural analysis, and preliminary report), as well as the detailed survey of timbers (with a special emphasis on visual strength grading on site) and carpentry joints. The subsequent diagnostic report and the detailed design of repairs are outside its scope. [ABSTRACT FROM PUBLISHER]

The paper presents the results of the restoration and conservation work which has been carried out in three archaeological areas in the Autonomous Province of Trento. The areas, which have been opened to the public for more than ten years, are the open-air archaeological site of Monte S. Martino, Roman Tridentum (an underground site under the historical city centre of Trento), and Fiavé (a pile dwelling site in a peat bog). These areas present very different environmental characteristics and have therefore required different interventions according to their specific situation. In order to reduce maintenance and extraordinary costs, appropriate conservation of the archaeological remains is required. This consists of methodologies of conservation according to the characteristics of the environment; continuous monitoring systems and indirect preventive intervention; and annual maintenance planning. [ABSTRACT FROM AUTHOR]

Thermogravimetry (TG) is used to measure the change of sample mass versus temperature or time under a program controlling temperature. It is a common thermal analysis tool with a precise built-in balance, and accurate data can be obtained through a small amount of sample at the level of milligrams. The feasibility of the TG method for determining maximum water content (MWC) measurement of waterlogged archaeological wood was studied. Simulated waterlogged wood and waterlogged archaeological wood were used to determine the test condition for the TG method. MWC data obtained through the oven-dry and TG methods with different mass gradients from 0–10 mg to >50 mg were analyzed statistically. Deviation, error bar, and coefficient of variation were evaluated. According to the results, when sample mass is no less than 30 mg, and holding time at 105°C is no less than 40 min, data deviation between these two methods is less than 5%. Effect of sampling depth and presence of inorganic deposits were also investigated. Specimens were taken from an archaeological wood with a sampling depth from 2 to 6 mm, then MWC was measured through the TG method. The results indicate MWC of the samples taken from a depth of 2–4 mm is higher than that taken from a depth of 0–2 mm and is lower than that taken from a depth of 4–6 mm, which is related to inorganic deposits. The presence of deposits was verified through SEM-EDX. MWC of three archaeological wood samples from China and five archaeological wood samples from Italy were measured to verify the effectiveness of the TG method when wood species and degradation degree are different. [ABSTRACT FROM AUTHOR]