Treat-Right Warranty

Through the use of next generation TANALITH E wood preservative together with the quality Pine timbers we use and their careful preparation ready for treatment, we offer a 20 Year Treat-Right Performance Warranty on our square sawn and round Pine agricultural fence posts to give you real confidence in your farm fencing projects.

View the Tanalised® Timber Smart Guide


Warranty Details

Covered is the cost of re-supply by Robertson Timber, or the re-supply by Robertson Timber (at our option), of a component that is proven to have failed as a result of fungal decay or insect attack. It does not cover the costs of removal or reinstatement of such components or consequential costs or loss due to failure of the component.

The term ‘fungal decay’ as used in the warranty refers to wood destroying fungi that feed on and degenerate the wood cell walls. It excludes staining and mould fungi associated with the weathering of wood.

The term ‘insect attack’ refers to attack by wood digesting insects that destroy the timber structure.
The term ‘failed’ refers to damage caused by insects and/or fungi to such an extent that the component is no longer fit for purpose.

Maintenance/Product Care
  1. Only Robertson Timber timber posts that have been treated to Use Class 4 must be used in ground contact situations – Use Class 4 (BS EN 335-1). Other Robertson Timber out of ground timber components such as rails and boards, that have been treated to Use Class 3, should only be used for out of ground contact situations – Use Class 3 (BS EN 335-1).
  2. Should the Robertson Timber pressure treated timbers be cross cut, notched or bored during installation, then exposed surfaces are to be liberally brushed with an approved brush-on end grain wood preservative to the directions shown on the product label. Cross cut, notched or bored surfaces must never be used in ground contact.
  3. Any Robertson Timber pressure treated timbers which are further processed, eg. planed, resawing, must be returned to Robertson Timber for re-treatment.
  4. All to comply with general business terms and conditions.
  5. We recommend all fencing should be periodically checked and maintained.

To achieve this 20 year warranty Robertson Timber Ltd impregnate their selected pine posts with a minimum of 320 litres of Tanalith 9000 per cubic metre of timber with a 4% solution strength. This equates to 26kg dry salt retention in the sapwood zone (average 50% sap/heartwood) or 13kg per cubic metre combined sap/heartwood timbers.

1. Any Robertson Timber pressure treated timber components supplied for use outside of European markets.
2. Any Robertson Timber pressure treated timbers removed from their original installation and re-used at a new location.

We recommend timber in ground contact be treated with a brush on preservative every two years. And every three years for fencing, garden sheds, planters etc. All preservatives available at Robertson Timber Ltd.

In an agricultural setting, we recommend spraying or brushing the neck of your stobs/posts at ground level periodically depending on condition.
Contact us for more advice.

This maintenance is paramount to the long life of the product. A well maintained fence will greatly exceed the treat-right warranty. 

It is important that the fence is maintained and all vegetation is kept clear of the fencing, as this voids the treat-right warranty. See below for example.

Due to the presence of a copper tolerant fungus in some parts of the UK. Customers that have experienced premature brown rot failure are recommended to periodically check the condition of their fencing, and if necessary, treat the neck of their posts and stobs/stakes with creosote to prolong the life of the product, The presence of creosote will help stop this soil borne fungus.


Don’t hesitate to get in touch if you have any queries about your next fencing project.