Disclosed herein is a timber preservative composition comprising: a boron compound, preferably selected from boric acid, water soluble borates and octaborates, and more preferably at least 65% w/v boric acid monoethanolamine, preferably between 15% to 25% w/w and water, preferably between 10% to 20% w/w wherein the composition has a Boric Acid Equivalent (BAE) of between 45% and 90%, preferably 80% w/v to 90% w/v. Additionally disclosed is a method for preparing a timber preservative composition comprising the steps of: mixing monoethanolamine and water together to form an aqueous solution, and adding a boron compound, preferably as a powder, to the aqueous solution, Additionally disclosed is a method for treatment of timber, said method comprising treating the timber with a timber preservative composition prepared by dilution of a treatment concentrate composition as described herein.
