Paineastetut

Paineastetut is a Finnish term used to describe materials that have undergone pressure treatment, most commonly wood that has been impregnated with preservatives under vacuum and pressure to improve durability against decay, moisture, and pests. The word derives from paine (pressure) and astettu (set or applied).

In practice, paineastetut wood refers to timber treated by a pressure impregnation process. The typical method, vacuum-pressure impregnation, involves drying the wood, applying a vacuum to remove air, introducing preservative solutions under higher pressure to force them into the wood’s pores, and then conditioning and drying. Variants include low-pressure methods and multiple treatment cycles. The goal is to extend service life for outdoor or ground-contact applications.

Common preservatives used in paineastettu wood have evolved over time. Modern formulations often rely on copper-based products such as copper azole or alkaline copper quaternary (ACQ). Older treatments, such as chromated copper arsenate (CCA), have been phased out or restricted in many regions due to health and environmental concerns. The choice of preservative and treatment schedule depends on wood species, intended end use, and regulatory requirements.

Environmental and safety considerations are important for paineastetut materials. Treating processes and leaching of preservatives are regulated, and proper handling, coating, and disposal are important to minimize environmental impact. Industry labeling and compliance with national and international standards govern the use and performance of paineastettu wood.

See also: Wood preservation, Pressure treatment, Impregnation.