Wood has been widely used by humans for millennia as a construction material and can be easily found in everyday life, anywhere around the world. Since wood is a natural, sustainable, and organic composite material, it can be affected by several wood-deteriorating agents under suitable climate exposure conditions, which may threaten the long-term performance of timber structures in their service life. In that context, this chapter covers the background, guidelines, and current research that can help engineers and architects when designing timber structures. It provides extended knowledge about different wood-deteriorating agents, the natural durability of wood, and the use class concept. Based on this, durability models can be established, taking into account the potential presence over time of wood deterioration agents and allowing design for improved service life. Preventive measures and protection systems can be defined from the beginning, whereas on-site monitoring and maintenance of timber structures should be continuously performed.

This article deals with the effect of various temperatures of thermal modification and fire retardants on selected burning characteristics and chemical wood components of teak (Tectona grandis L. f.) wood. The thermal modification was carried out at temperatures 160 °C, 180 °C and 210 °C. Subsequently, thermally modified wood was treated by natural (arabinogalactan) and synthetic (ammonium phosphate) fire retardants. The effect of thermal modification as well as fire retardant was detected by burning characteristics such as weight loss, burning rate, maximum burning rate, ratio of the maximum burning rate and time to reach maximum burning rate. The chemical changes caused by the influence of these factors were determined by changing the content of cellulose, hemicelluloses, holocellulose, lignin and extractives. The relationship between burning characteristics and chemical changes in the thermally modified wood was analyzed using Spearman’s correlation. The results showed that the thermal modification of teak wood had a negative effect on its ignition and burning properties. Synthetic fire retardant had the highest retardation effect in all cases. The natural fire retardant caused a better retardation effect on thermally modified wood at temperature 180 and 210 °C. The relative content of lignin, extractives and cellulose increased, while the amount of holocellulose and particularly hemicelluloses decreased.

Thermally modified wood is becoming an increasingly popular material for different applications in buildings. Laboratory tests indicated a positive effect of thermal modification on durability, dimensional stability and thermal conductivity of wood. Therefore, windows and facade elements made of thermally modified Norway spruce and non-modified Norway spruce were tested in the field and installed in different test objects which were exposed at five locations in Europe (Slovenia, Germany, Sweden, and Spain). Results from monitoring showed that elements and windows made of thermally modified spruce (TMS) had considerably lower wood moisture content compared to the ones made of non-modified spruce and that wax further positively influenced moisture performance. Colour changes of TMS were more intensive compared to non-modified spruce but were successfully retarded by adding pigments to the wax. Mould and stain growth was largely dependent on the location, amount of precipitation and relative humidity.

Nowadays, wood modification is referred to as a process used to improve the physical, mechanical, or aesthetic properties of sawn timber, veneer or wood particles used in the production of wood composites. Though many aspects of these treatments are known, the fundamental influence of the process on product performance, the environment, and end of life scenarios remain relatively unknown. It is essential to integrate interactive assessment of process parameters, developed product properties, and environmental impacts. To optimize modification processing to minimize environmental impacts, much more information must be gathered about all process related factors affecting the environment. Wood modification represents an assortment of innovative processes currently being adopted in the wood protection sector or are at different stage of development (Fig. 1). These processes produces a material that can be disposed at the end of a product's life cycle without presenting any environmental hazards greater than those that are associated with the disposal of unmodified wood. 

Performance of Bio-based Building Materials provides guidance on the use of bio-based building materials (BBBM) with respect to their performance. The book focuses on BBBM currently present on the European market. The state-of-the-art is presented regarding material properties, recommended uses, performance expectancies, testing methodology, and related standards.

Chapters cover both ‘old and traditional’ BBBM since quite a few of them are experiencing a comeback on the market. Promising developments that could become commercial in the near future are presented as well.

The book will be a valuable reference resource for those working in the bio-based materials research community, architects and agencies dealing with sustainable construction, and graduate students in civil engineering.