Superwood

Superwood® is a Danish company founded 25 years ago with the objective of developing a process capable of fully impregnating spruce timber. The result is a proprietary treatment technology designed as a sustainable and robust alternative to conventional vacuum and pressure impregnation methods. The process does not use heavy metals or water and requires only a minimal amount of impregnating agent—approximately one gram per board—while achieving Durability Class 1 for above-ground outdoor applications (Use Classes 3.1 and 3.2). The product is suitable for façade cladding and other exterior uses.

A focus on responsible design, resource management and consumption standards has led to Cradle to Cradle certification at Gold level for unpainted products and Silver level for colour-treated variants. This supports its use in projects targeting sustainable building certification.

The production process is CO₂-neutral, partly due to energy-optimised manufacturing methods. A key element is the impregnation technique using supercritical CO₂ technology. Under pressures of up to 150 bar, CO₂ reaches a supercritical state, enabling the treatment agent to penetrate deeply into the timber structure. Superwood reports that it is currently the only company applying this specific technology at commercial scale.

The natural characteristics of Finnish spruce—such as colour, scent and weight—remain unchanged after treatment. When left untreated, the timber retains a natural appearance, but it can also be finished in a wide range of colours, including lighter tones. Only centre-free timber with live, solid knots and a fine annual ring structure is selected. Each plank is inspected using X-ray technology and oriented during planing so that the centre side becomes the visible face.

Superwood provides product-specific Environmental Product Declarations (EPDs) for its standard profiles and finishes. In the Netherlands, façade boards are commonly supplied at 18 mm thickness; Superwood boards are delivered at 22.5 mm as standard, providing additional rigidity. An optional tongue-and-groove end-matching system allows boards to be connected independently of the supporting substructure. This can reduce cutting waste and installation time.

Several profiles have been developed in collaboration with architects, with selected designs named after their designers.

Superwood complies with Fire Class D as standard and can achieve Fire Class B when treated with an approved fire-retardant coating. The product is suitable for both horizontal and vertical ventilation systems, offering flexibility in façade design for residential and non-residential projects.