This study aimed to evaluate the impact of thermal modification on the physical and mechanical properties of three different wood species from Bosnia and Herzegovina, namely beech wood (Fagus sylvatica L.), linden wood (Tilia cordata), and silver fir wood (Abies alba). The samples underwent thermal modification at five different temperatures (170 °C, 180 °C, 195 °C, 210 °C, and 220 °C) for varying durations (ranging from 78 to 276 min). After treatment, they were exposed to outdoor conditions for twelve months. The study examined the four-point bending strength, tensile force, color change, and surface quality of the modified and unmodified samples. The results showed that outdoor exposure negatively impacted the mechanical properties of the unmodified samples, especially in the linden wood which was 41% and the beech wood which was 42%. Additionally, outdoor exposure caused significant surface cracks in the thermally modified linden and beech wood. The study also found prominent color changes in the modified and unmodified samples during twelve months of exposure. The roughness of the samples was determined with a confocal laser scanning microscope, which showed that the roughness increased on both the axial and the longitudinal surfaces after weathering. The highest roughness for the fir wood was determined to be 15.6 µm. Overall, this study demonstrates the importance of wood modification and its impact on the use-value of wood products.

Timber structures have been a popular choice for construction due to their natural and aesthetic appeal. However, with the increasing focus on sustainability and eco-friendliness, alternative building materials are gaining popularity. One such material that has gained attention is coconut wood. Coconut wood is a by-product of the coconut industry and has several unique properties that make it an excellent choice for timber structures. This paper reviews the properties and applications of coconut wood in timber structures and discusses its advantages, limitations, and challenges. We discussed the physical and chemical properties and durability of coconut wood. The average density of coconut palm wood ranges from 0.41-1.11g/cm³, while its moisture content ranges from 50% to 400%. Coconut wood has low shrinkage and swelling rates, reducing the risk of cracking or warping. The holocellulose content is about 67% while the lignin content is approximately 25%. Chemical and natural products, are effective in protecting coconut wood against decay and insect attack. Understanding such characteristics of coconut wood is critical for its optimal utilization in various industries. By employing appropriate preservation techniques and utilizing this versatile and sustainable resource, coconut wood can continue to provide significant benefits for communities and industries around the world.

This study investigates innovative surface coatings’ effectiveness in enhancing spruce wood’s fire resistance (Picea abies spp.). Spruce wood samples were treated with various agents, including oils, waxes, boric acid, commercial coatings, and fire-retardant agents. The evaluation was conducted using the small flame method (EN ISO 11925-2:2020), surface roughness analysis, hyperspectral imaging (HSI), and contact angle measurements. The results demonstrated significant improvements in fire resistance for samples treated with specific coatings, particularly the Burn Block spray and Caparol coating, which effectively prevented flame spread. The analysis revealed that the Burn Block spray reduced the average flame height to 6.57 cm, while the Caparol coating achieved a similar effect with an average flame height of 6.95 cm. In contrast, untreated samples exhibited a flame height of 9.34 cm, with boric acid-treated samples reaching up to 12.18 cm. Char depth measurements and the surface roughness analysis revealed a clear correlation between the type of treatment and the thermal stability of the wood. Hyperspectral imaging enabled a detailed visualisation of surface degradation, while contact angle measurements highlighted the impact of hydrophobicity on flammability. This research provides in-depth insights into the fire-retardant mechanisms of spruce wood and offers practical guidelines for developing safer and more sustainable wood materials for the construction industry.

Wood finger joints are widely used in both structural timber and high-quality furniture due to their ability to create long, continuous members from shorter pieces. The mechanical performance of these joints depends not only on the wood species but also on the geometry of the interlocking teeth and the quality of the adhesive bond. This study explores how the geometry of finger joints affects the tensile behavior and fracture characteristics of beech (Fagus sylvatica L.) and oak (Quercus robur L.). Specimens with varying tooth dimensions were tested using a 50 kN universal testing machine from Shimadzu. Key metrics such as ultimate tensile load, effective cross-sectional area, cohesive stress, energy required to cause failure, and fracture energy (G_c) at 0.5, 1.0, and 2.0 mm displacements were systematically measured. The results revealed that beech specimens achieved ultimate tensile loads up to 21,320 N and cohesive stress of 204 MPa, while oak reached 21,631 N with a cohesive stress of 239 MPa. Fracture energy (G_c) values ranged from 0.036 N/mm for beech to 0.051 N/mm for oak, depending on joint geometry. Results show that both the type of wood and the tooth design, including width and length, play a decisive role in joint performance. In general, longer teeth and larger bonded areas improved tensile capacity and increased resistance to fracture. These findings offer deeper insights into the fracture mechanics of hardwood finger joints and provide practical guidance for optimizing glued connections in furniture and structural timber. The collected data can also support accurate modeling, quality assurance, and numerical simulations in future studies.

Wood modification has been developed as a non-biocidal concept to overcome inherent material limitations such as dimensional instability and biological durability. But sustainability assessment must extend beyond initial functional performance to include machinability, interface compatibility, repairability and end-of-life (EoL) cascade potential. This critical narrative review integrates the mechanisms, processing dynamics and circular-economy implications of 4 major modification routes: thermal treatment, acetylation, furfurylation and thermo-hydro-mechanical (THM) densification. We examined a purposive sample of 40 peer-reviewed articles including seminal citations between 1990-2007 and recent publications between 2021-2025. The synthesis shows that thermal modification and acetylation can enhance hygroscopic and di-mensional stability through different mechanisms, but with different trade-offs in mechanical toughness and secondary processing. Furfurylation can improve hardness and decay resistance, but also increase brittleness and recycling difficulties. THM densification improves the local load bearing capacity, but moisture-induced set-recovery is a major limitation. Cross-contamination in heterogeneous waste streams, residual chemical matrices, changed surface-energy interactions with adhesives, and limited standardization of sorting protocols are important barriers to circular material loops across the modification routes. A descriptive particleboard case-study dataset covering 0–70% secondary-wood fractions shows decreasing MOR, MOE and IB and increasing thickness swelling with increasing recycled content. These observations are presented as only study-specific descriptive evidence, and not as evidence of a universal recycling threshold or formal EN 312 P2 conformity, as the current experimental documentation does not contain sufficient information on independent panel replication and inferential statistical analysis. Future work should consider design for disassembly, digital material traceability and multi-criteria sustainability assessment.