Measurement of Moisture in Wood for Application in the Restoration of Old Buildings

There are many historic buildings whose construction is based on timber frame walls. Most buildings built during the nineteenth and early twentieth centuries were based on timber frame walls with vertical support elements. These timber frame elements are affected by their moisture content and by the passage of time. If the interaction of the timber frame walls with hygrothermal fluctuations were known, the maintenance of these buildings could be improved significantly. To determine the moisture content of wood there are two types of meters on the market: on the one hand, capacitance meters which consist of two side ends and where the moisture content is measured locally between two peaks. On the other hand, there are meters based on the variation of electromagnetic transmittance of timber, which depends on the moisture of timber. The second ones are very expensive and difficult to handle. This work presents a new non-intrusive capacitive sensor that measures the global moisture content in a section of the timber frame walls and therefore its accuracy is similar to the accuracy that can be obtained with electromagnetic transmittance meters. Additionally, as it is a capacitive sensor, it is low cost and easy to operate.

[1]  Nicola Macchioni,et al.  A case study: The evaluation of biological decay of a historical hayloft in Rendena Valley, Trento, Italy , 2014 .

[2]  Frédéric Dubois,et al.  Modeling of the viscoelastic mechano-sorptive behavior in wood , 2012 .

[3]  Olaf Schmidt,et al.  Wood and Tree Fungi: Biology, Damage, Protection, and Use , 2006 .

[4]  M. D’Orazio,et al.  Study on some sorption properties of treated bentonites for their potential use as a moisture regulating system for the preservation of historical wooden elements , 2010 .

[5]  Jakub Sandak,et al.  Application of imaging techniques for detection of defects, damage and decay in timber structures on-site , 2015 .

[6]  Robert A. Blanchette,et al.  A review of microbial deterioration found in archaeological wood from different environments , 2000 .

[7]  Pernilla Johansson,et al.  Validation of critical moisture conditions for mould growth on building materials , 2013 .

[8]  Emine N. Caner-Saltik,et al.  In situ assessment of structural timber elements of a historic building by infrared thermography and ultrasonic velocity , 2007 .

[9]  Brigitte Leblon,et al.  Determination of log moisture content using ground penetrating radar (GPR). Part 2. Propagation velocity (PV) method , 2015 .

[10]  Roger M. Rowell,et al.  Historical wood – structure and properties , 2012 .

[11]  E. Schilling,et al.  Time-Domain Reflectometry for the Prediction of Loblolly Pine and Sweetgum Moisture Content , 2015 .

[12]  R. Černý.  Time-domain reflectometry method and its application for measuring moisture content in porous materials: A review , 2009 .

[13]  T. Toratti,et al.  Mechanical response of wood perpendicular to grain when subjected to changes of humidity , 2002, Wood Science and Technology.

[14]  R. Klaassen.  Bacterial decay in wooden foundation piles—Patterns and causes: A study of historical pile foundations in the Netherlands , 2008 .

[15]  J. Papez,et al.  Wood moisture of rural timber constructions. , 2013 .

[16]  H. S. Kol.  THERMAL AND DIELECTRIC PROPERTIES OF PINE WOOD IN THE TRANSVERSE DIRECTION , 2009 .

[17]  René K W M Klaassen,et al.  Wooden foundation piles and its underestimated relevance for cultural heritage , 2012 .

[18]  A. Manninen,et al.  Comparing the Effect of Chemical and Physical Properties on Complex Electrical Impedance of Scots Pine Wood , 2003 .

[19]  V. V. Kozlov,et al.  Sorption properties of historic and recent pine wood , 2014 .

[20]  G. Schajer,et al.  Measurement of wood grain angle, moisture content and density using microwaves , 2006, Holz als Roh- und Werkstoff.

[21]  P. Rubio de Hita,et al.  Use of ultrasound as a nondestructive evaluation technique for sustainable interventions on wooden structures , 2014 .

[22]  H. Arthaber,et al.  Contactless moisture content and density evaluation of sawn timber using microwave transmission , 2014 .

[23]  David Hunt,et al.  Properties of wood in the conservation of historical wooden artifacts , 2012 .

[24]  Zoubir Mehdi Sbartaï,et al.  Non-destructive evaluation of moisture content of wood material at GPR frequency , 2015 .

[25]  B. Gutarowska,et al.  Colonising organisms as a biodegradation factor affecting historical wood materials at the former concentration camp of Auschwitz II – Birkenau , 2014 .

[26]  F. García-García,et al.  Estudio de la variación del contenido de humedad en el Pinus Pinaster Ait por medio de la técnica no destructiva del georradar , 2011 .

[27]  E. Gelhaye,et al.  Density mapping of decaying wood using X-ray computed tomography , 2014 .

[28]  Elisabetta Rosina,et al.  Moisture detection in wood and plaster by IR thermography , 2004 .