Warranty Information - 15-year Warranty

Osmose Naturewood Plus+ pressure treated timbers from Calders & Grandidge, when used in the appropriate Use Class (UC) situations, have a 15 year guarantee against failure of the timber from fungal decay or insect attack.

The guarantee is for the cost of re-supply by Calders & Grandidge, or the re-supply by Calders & Grandidge (at our option), of a component that is proven to have failed as a result of fungal decay or insect attack within 15 years of supply.

It does not cover the costs of removal or reinstatement of such components or consequential costs or loss due to failure of the component. Claims must be brought within two weeks of the expiry of the 15-year period, at the latest and must be accompanied with proof of purchase and a sample of the failed timber.

The terms “rot” and “fungal decay” as used in this Guarantee mean attack by wood destroying fungi that disintegrate the wood cell walls but do not include staining fungi associated with the “weathering” of wood. “Weathering” of wood is not fungal decay or rot of any type or definition.

The term ‘insect attack’ refers to attack by wood destroying insects that destroy the timber structure such as termites.

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.

This guarantee does not affect the statutory rights of the consumer.

Warranty Information - Best Practice Installation Facts

  • Only treat timber products in their final dimensions.
  • Re-working at the installation site should be limited to cross cutting, boring, drilling or notching. All exposed surfaces should then be given two liberal brush coats of a suitable preservative as recommended by the manufacturer of the industrial wood preservative used in the original treatment.
  • It is important to remember that the penetration achieved by brush is less than that achieved in the pre-treatment process and it is best to avoid or minimise re-working.
  • Treated wood must never be rip sawn along its length. If this takes place, it must be returned to the treatment plant and retreated prior to use.
  • The cross cut end of treated timber must never be embedded in the ground.
  • If using a cement-based mix to fix timber in the ground, ensure that water can drain away. Do not make a ‘boot’ for timber out of concrete, as this will keep the bottom of the timber wet for long periods and increase the risk of decay. For treated timber to be used in Use Class 4 always put an uncut end in the ground.

Warranty Information – Conditions

  1. Only Calders & Grandidge Naturewood Plus+ Timber treated to Use Class 4 must be used in ground contact situations.
  2. Should the Calders & Grandidge Naturewood Plus+ pressure treated timbers be cross cut, notched or bored during installation, then exposed surfaces must be coated with a suitable end coat preservative according to the correct application directions.
  3. Timber must not be pointed after treatment.
  4. The shortening of timber should be avoided, if possible, but in any event the cut end must never be used in ground contact.
  5. Any Calders & Grandidge Naturewood Plus+ pressure treated timbers which are to be used in ground contact and are further processed, e.g. planed, must be returned to Calders & Grandidge for re-treatment.

Warranty Information - Exclusions

This warranty does not apply to:

  1. Any Calders & Grandidge Naturewood Plus+ pressure treated fencing components supplied for use outside of European markets.
  2. Any Calders & Grandidge Naturewood Plus+ pressure treated timbers removed from their original installation and re-used at a new location.
  3. Any damage caused to products used in commercial or industrial structures.
  4. Building poles, commercial vineyards stakes or peeler core landscape timbers.
  5. Damage caused by ‘weathering’ of wood, including but not limited to raised grain, splitting, cracking, twisting, warping, shrinkage, swelling or any other physical property of the wood, or where untreated material is exposed by the effects of this weathering.
  6. Timber degrade which is the result of the natural movement of wood in service, including weathering, twisting and splitting of components.

Naturewood Plus+ Timber 

Working in co-operation with Osmose we are implementing quality procedures that will enable us to produce timber products with in ground contact that carry a 15-year service life warranty.

Naturewood Plus+ Timber is treated in accordance with quality procedures, which have been set out by Osmose Timber Technologies. These procedures are regularly audited by Osmose to ensure the standards are maintained.

All timber for the warranty scheme is selected to ensure greater treatment penetration and long-term protection for in ground contact material. When ordering treated products it is important to specify the Use Class required and for posts this is Use Class 4 (UC4).

Our in ground contact timber with a 15-year warranty will be sold as a new product range ‘Naturewood Plus+’. By ordering these products you can have confidence that it has been treated to be ‘fit for purpose.’