Timber treatment

Nearly all of the timber we stock in our Cumbrian base is pressure treated, which means it will have been impregnated with TANALITH®E wood preservative under rigidly controlled conditions in our own on-site vacuum pressure timber impregnation plant.

The resulting TANALISED®E pressure treated timber has a natural pale green colouration. However, if specifically required, fencing and landscaping timbers can also be treated with a built-in brown TANATONE® colouration.

At Rose Bank Sawmill we treat our products to hazard class 4, which is the highest protection level. All of this means you can enjoy greater peace of mind that your timber will have a longer and low maintenance service life.


Before any of our agricultural posts are treated with TANALITH®E wood preservative, all of the bark is removed, and the timber is dried to the correct moisture content.

Treatment on all other timber and timber products we supply will only be undertaken when the correct moisture content is reached. This is important as incorrect moisture content will not give the timber the maximum protection we and our customers require.

To discover more about TANALISED® timber, please click here.

  1. The timber is placed into our industrial treatment cylinder and an initial vacuum is created. The timber cells are evacuated of air and the vacuum is held.
  2. The cylinder is then flooded with TANALITH®E wood preservative.
  3. Hydraulic pressure is applied, forcing the preservative into the timber cells.
  4. A final vacuum extracts preservative solution, which is then pumped back into storage.
  5. Low pressure inside the timber draws in surface preservative solution when vented to atmosphere. The treated timber is then stored for a minimum of 48 hours before it is despatched.