Treated timber is highly versatile. It is used extensively both inside and outside houses and commercial buildings, and in landscaping.
Treatment is carried out by impregnation of the timber, under vacuum and pressure.
After treatment and re-drying the tanalised preservative becomes substantially part of the cellular structure of the timber. It can not be removed by weathering, rain, wetting, soaking or scrubbing. The treatment can never be washed out.
The preservative chemicals are toxic to insects and fungi, which is, of course, their purpose. Provided that common sense precautions are observed, preservative chemicals do not present a hazard to humans when fixed in the dried timber.
Under normal circumstances, plants and animals in contact with Tanalised treated timber will be perfectly safe. Care should be taken with certain specific applications such as birdcages, beehives and fishponds.
Sometimes a white powder will appear on the surface of the timber. This is mostly Sodium Sulphate, a harmless substance which, if necessary, can be simply brushed or hosed off.
Dry Tanalised treated timber can be painted or stained in the same manner as untreated timber.