Puurakenteen

Puurakenteen, or wood structure, refers to a construction system in which timber is the primary structural material. It encompasses traditional timber framing as well as modern engineered wood products such as cross-laminated timber (CLT), glulam, laminated veneer lumber (LVL), and plywood panel systems. Timber structures are used in residential, commercial, and civil projects because of a favorable strength-to-weight ratio, relative simplicity of fabrication, and potential for lower embodied energy when sourced from sustainably managed forests.

Construction approaches vary. Light-frame construction uses dimension lumber and smaller components to form walls, floors, and roofs, while heavy timber construction employs large-dimension members connected with joints and metal fasteners, widely recognized for its robustness and fire performance. In recent decades, mass timber systems such as CLT panels and glulam beams enable long spans and column-free floors, facilitating rapid assembly and flexible layouts.

Key considerations include moisture management, durability, and fire safety. Timber is susceptible to decay and insects without proper detailing, treatment, or enclosure. Design must address moisture exposure, ventilation, and drainage. Fire performance can be favorable due to charring behavior, but engineers must account for retained section, exposure conditions, and protection of connections.

Environmental aspects: timber is renewable when harvested from certified forests and stores carbon during growth. Life-cycle energy use can be lower than concrete or steel for certain applications, though embodied energy varies by species, processing, and transportation. Standards and codes govern design and construction, such as Eurocode 5 and national equivalents, with design values dependent on species, moisture content, and connection details.

See also: cross-laminated timber, glulam, laminated veneer lumber, timber frame, sustainable construction.