For millennia, getting durable outdoor timber meant cutting slow-growing tropical species, destroying primary forests, or impregnating pine with toxic copper compounds. Accoya solves the paradox: it chemically transforms fast-growing plantation pine into the most durable and stable wood on the planet, without using any poison.
Raw Radiata Pine boards enter large autoclaves saturated with acetic anhydride under pressure and heat. Free hydroxyl groups (OH), those that bind moisture causing swelling, are permanently replaced by acetyl groups (Ac), which are larger and fill the cell wall space preventing water molecules from penetrating. The wood becomes structurally hydrophobic from core to surface.
Accoya, unable to absorb water, reduces its dimensional movement by 80%. An installed board will stay perfectly flat for decades. Applied paints last three to four times longer than on conventional wood, because the surface does not work and does not tear the paint film.
Standards
European and international references applicable.
Physical properties
Usage environment
CRITICAL HARDWARE: the acetylation process leaves a slight residual acetic acid inside the wood. This triggers strong galvanic corrosion on standard or galvanised steel. It is mandatory to use exclusively A2 or A4 stainless steel fixings (AISI 304/316). GREYING: if left bare without UV varnishes, it will naturally assume a silver-grey patina like Teak.