When it comes to fencing solutions, pressure treated timber is a popular choice among homeowners and landscapers for its durability, resistance to decay, and long lifespan. In this article, we explore everything you need to know about pressure treated timber, from the treatment process to its advantages over non-treated timber, and its maintenance requirements.

What Does Pressure Treated Mean?

Pressure treated timber refers to wood that has undergone a specific treatment process which enhances its durability and resistance to decay. The treatment involves infusing the timber with chemical preservatives such as copper azole, alkaline copper quaternary, or chromated copper arsenate, under high pressure to ensure deep penetration into the wood fibres.

This process significantly extends the lifespan of the timber, making it a reliable and cost-effective choice for many outdoor applications such as fencing, decking, garden furniture, and landscaping structures.

How is Timber Pressure Treated?

The pressure treating process involves several key steps:

  1. Preparing the wood: Before treatment, the timber is air-dried to reduce its moisture content and prepared by removing any bark, knots, or other defects.
  1. Treating the wood: The prepared timber is placed in a sealed pressure cylinder, and a vacuum is applied to remove any remaining air and moisture from the wood.
  1. Applying chemicals: Preservative chemicals are then introduced to the cylinder, and the pressure is raised to force the chemicals deep into the wood fibres.
  1. Post-treatment: After treatment, the timber is removed from the cylinder and allowed to dry before use.

Pressure Treated vs Non-Treated Timber

Pressure treated timber offers several advantages over non-treated timber, including:

  • Longevity: Pressure treated timber lasts significantly longer than non-treated timber, typically providing 15 to 20 years of service in outdoor conditions, depending on factors such as the specific preservative used, environmental conditions, and maintenance.
  • Resistance to decay: The chemical preservatives used in pressure treatment help the timber resist fungal decay, wood rot, and insect damage, making it ideal for outdoor use.
  • Low maintenance: Pressure treated timber requires minimal maintenance, compared to non-treated wood which may need regular sealing, staining, or painting to protect it from the elements.

However, pressure treated timber can be more expensive initially than non-treated alternatives, and may have a slight greenish hue due to the chemicals used.

How Long Should Pressure Treated Timber Last?

The longevity of pressure treated timber largely depends on the type of environment it is in and the maintenance received. In general, you can expect a pressure treated fence to last around 15 to 20 years in most outdoor settings.

Does Pressure Treated Timber Require Re-Treatment?

While pressure treated timber is resistant to decay and insect damage, it may still need re-treatment to maintain its durability and appearance over time. It's essential to periodically inspect your pressure treated fence and clean it regularly using a mild detergent and water.

If you notice any signs of deterioration, you may need to reapply a high-quality exterior wood preservative or sealer to help protect the wood from moisture and UV damage.

In Conclusion

Pressure treated timber is a versatile and durable choice for many outdoor applications, including fencing. By understanding the treatment process, the difference between pressure treated and non-treated timber, and the maintenance requirements, you can ensure a long-lasting and beautiful fence that meets your needs.