Tanalith and Vacsol timber treatments


Wood is an excellent renewable material used in the building industry. However, being organic, it can be attacked by pests like wodworm (insects) and dry rot (fungi). To prevent this it must be reated with preservatives before its use.

Traditional wood preservatives contain chromium copper arsenate (CCA). Although studies have shown CCA to be safe, some groups have raised concerns about arsenic getting into the environment. Arch Timber Protection have developed treatments that are free from arsenic but just as effective as CCA.

"Tanalith E" uses copper and an organic azole biocide as its active ingredients. Treated under pressure, the Tanalith E penetrates deep into the wood and chemically links to it. This gives the wood protection against attack by insects and fungi for many years.

Another product, "Vacsol Aqua", contains completely biodegradeable fungicides and insecticides. It can be used to treat wood that is used in the construction of houses.


Pressure treatment process

Pressure treatment with Tanalith E

Timber is placed in a chamber and all the air is pumped out. This vacuum draws water out of the wood cells.


Chamber is flooded with solution of Tanalith E.



Pressure is applied to force solution into timber.


Excess solution is pumped out of chamber. Wood is kept under low pressure in a vacuum.


When chamber is opened to atmospheric pressure, the final surface layer of Tanalith E is forced into the wood.