The Benefits of Large Durable Hardwood Posts

Mixed Ironbark and Spotted Gum Hardwood Posts

Large, durable hardwood posts are a popular choice for a range of outdoor and structural applications but sourcing the right product can sometimes be a challenge. In the past, the time between enquiry, quoting, ordering and delivery has made it difficult to secure large hardwood posts when they are needed.

To help address this, Bowens Hastings now has a range of large, durable hardwood posts in mixed Ironbark and Spotted Gum. Graded to a minimum F14, these posts offer the strength, durability and versatility required for a range of construction applications.

Features and Benefits

Sound Boxed Heart

These mixed Ironbark and Spotted Gum hardwood posts feature a sound boxed heart centre profile, providing balanced structural performance and helping to maintain straightness. While free-of-heart-centre (FOHC) timber may display less cracking, it is not necessarily desirable for large hardwood posts for several reasons:

• Smaller regrowth logs: Today’s timber resource is increasingly made up of smaller regrowth logs, making it difficult to achieve FOHC timber, particularly in 200 x 200mm sections.
• Straightness: FOHC timber can be difficult to keep straight because it tends to follow the natural contour of the tree. This becomes more pronounced in longer lengths, particularly over approximately 3 metres.

Durability Ratings

Under Australian Standard AS 5604, both Ironbark and Spotted Gum have a Class 1 durability rating for above-ground applications, with an expected service life of 40 years.

For in-ground applications, Ironbark is rated Class 1, with an expected service life of 25 years, while Spotted Gum is rated Class 2, with an expected service life of 15 to 25 years.

Timber Treatment

H4 treatment applies to the Spotted Gum component and only where treatable sapwood is present, providing protection against borer and termite attack. H4 treatment allows the timber to be used in in-ground applications.

Structural Capacity

The posts are graded to a minimum F14 structural grade. That said, timber appreciates in strength as it seasons.

Green Off-Saw (GOS)

Unseasoned timber naturally dries over time after installation. Accordingly, there can be

shrinkage with surface checking/splitting expected as gradual seasoning takes place.

BAL 29 Bushfire Rating

Both Ironbark and Spotted Gum have a high BAL 29 bushfire rating.

Ironbark and Spotted Gum species deliver dependable performance across a range of outdoor construction projects, including fencing, retaining walls, pergolas and structural posts. We recommend sealing the end grain with an oil-based coating, to slow moisture gain or loss in the natural drying process of an unseasoned product. Where a post is installed in-ground, apply a bitumen coating to the section below ground level.

Bowens Hardwood Posts

Bowens currently has the following large hardwood posts in stock at its Hastings store. It is graded to (minimum) F14 grade in mixed species; mainly Spotted Gum and Ironbark.

The Spotted Gum component is H4 treated where treatable sapwood is present. As sapwood typically represents a relatively small proportion of the finished product, the extent of treatment will vary between individual posts.

160x160mm Mixed Ironbark/ Spotted Gum

Class1 & 2, unseasoned, Available in lengths 2.7m, 3.0m & 3.6m.

200x200mm Mixed Ironbark/ Spotted Gum

Class1 & 2, unseasoned, Available in lengths 2.7m, 3.0m, 3.6m, 4.2m & 4.8m.

For more information on hardwood posts, feel free to contact Bowens Hastings. Drop into your local store to chat about structural hardwood timbers and pine framing readily available.