Wood can be used to construct sophisticated buildings with a high aesthetic appeal.

The woody tissue of trees is formed by longitudinally aligned fibers, providing support to the tree and facilitating nutrient transport. Earlywood (Spring) grows rapidly, being less resistant, while latewood (Summer) grows more slowly, being darker and more durable. Density is directly linked to mechanical properties, where higher density results in greater strength and durability due to lower porosity.

Tropical woods, with more consistent year-round growth, have more homogeneous wood, making it difficult to identify growth rings. The cellular organization explains the anisotropy of wood, exhibiting distinct mechanical responses in different directions relative to the fibers.

Mechanical behavior is affected by the presence of knots, which divert fibers, reducing resistance to axial tension. Wood without knots or with smaller knots is considered of higher quality, with superior mechanical strengths. Wood is unique in allowing the prediction of its mechanical behavior through visual analysis.

Erroneously, wood is often associated with low durability, but there are examples of wooden constructions that withstand for centuries. The primary agent of degradation is water, with fire being the most severe, although less frequent. The presence of water increases the moisture content in wood, creating conditions for fungi, insects, and termites. Maintaining moisture content below 20% is an effective preventive measure.

Different wood species have varied natural durabilities, and the designer should choose those most suitable for the application. If necessary, wood can be treated, but not all species are treatable in the same way. The durability of the construction depends on construction details, with emphasis on ventilation and prevention of water accumulation in contact with wood. Reducing direct contact with wood, especially in the longitudinal direction, prevents water penetration into the fibers.

Wood is easy to cut and drill, which sometimes can lead to negligence or underestimation at the construction site. The perception that anyone can work with wood due to its ease often hinders wood construction. However, wood construction incorporates modern and advanced digital technologies. The emphasis on prefabrication, digitization, and Building Information Modeling (BIM) showcases the forefront of the wood industry. Wood construction is inherently prefabricated, utilizing technologies like CAD/CAM and CNC to produce elements with millimeter precision.

Based on the analogy of wood's constitution with longitudinally oriented fibers in the trunk, it becomes simple to understand this concept. Wood exhibits different physical and mechanical performances concerning the direction of the fibers. In the direction of the fibers, the mechanical strength in tension and compression is high, but the porosity is also greater, facilitating water circulation. Meanwhile, in the perpendicular direction, the tensile strength is very low. The compression strength perpendicular is inferior to the parallel direction, but it presents a ductile behavior, skillfully exploited by carpenters in the design of connections with notches, tenons, dowels, etc.

A joint represents the union of various elements, which often have different directions and inclinations. Given that wood is an anisotropic material, with properties dependent on direction, joints become the weakest elements in wood construction. These elements exhibit distinct behaviors due to different stresses in relation to the fibers.

The most common connectors in wood construction, such as screws, nails, and dowels, transmit forces mainly through shear. Although there are connectors that transfer part of the forces through axial forces, the design of joints must consider that the predominant transfer occurs through shear, with deformation of the connector and localized crushing of the wood.

What makes working with wood so special is the need to know and understand the material. For example, even with precise calculations, choosing an unsuitable wood species for the desired durability can result in a construction with a short lifespan and unsatisfactory performance. However, armed with this knowledge, building with wood becomes a fantastic experience.