Karri Decking

Overview

The “Karri” tree is Australia’s and one the world’s tallest hardwoods growing up to 70m in height, allowing for longer lengths of timber being able to be milled, knot-free. Karri heartwood is a beautiful hue of reddish-brown, being slightly lighter in colour then jarrah. Also like Jarrah, the Karri grows in the wetter regions of southwest WA and also cultivated internationally. Availability of Karri is slightly greater then Jarrah, but still limited due to the most of the timber now in conservation reserves and regrowth forest. Karri timber has an interlocked, sometimes straight grain, with a course texture. Karri is moderately durable, with a reputation of being termite-prone, however not nearly as prone as pine.

Karri Decking
Karri Decking

 

Pros & Cons

PROS CONS
Longer lengths of timber available, knot-free Termite-prone
Cheaper than other hardwoods, like jarrah and ironbark Somewhat limited in availability
Often used as flooring too, can use decking to create a continuous flow from inside to out Pre-drilling required
High strength Poor reputation to holding paint and impregnation of preservatives
Mostly supplied in random lengths
Not as durable as other Australian hardwoods

 

Properties

Name Eucalyptus Diversicolour
Colour (Heartwood) Reddish brown
Colour (Sapwood) Pale greyish brown
Durability Class 2
Density 900 kg/m3
Hardness Janka rating 9
Checking rating
Shrinkage rating
Availability Limited Availability
BAL Rating 12.5
19
Termite Resistant NO
Lyctid Borer Susceptible NO
Tannin Leach Little
Origin WA