Cumaru Timber Guide

Cumaru is a new hardwood species added to our range of offerings and is perfect for both internal and external applications. The various benefits, technical information and FAQs that cover just about everything you would need to know about Cumaru is mentioned here.

Cumaru Wood Species

The Cumaru Hardwood (also referred to as Southern Spotty or Southern Spotted Gum) is native to the Southern Hemisphere and comes from the Dipteryx Odorata Tree. This species is often found in tropical environments in Central America, South America, Peru, and Colombia, which may just be the reason behind its toughness.

Not only is this timber incredibly strong due to its interlocked grain, but it is also exceptionally stable with its popularity quickly growing worldwide. The Cumaru lumber is recognised across the industry for its stiffness, strength, and hard finish, which enables it to be used in a variety of residential and commercial applications. What’s more is the natural hardness and oils infused in Cumaru, creates a naturally treated wood which will stand the test of time in any environment.

The versatile Cumaru hardwood is typically used in applications such as flooring, decking, bridges, boardwalks, marinas, pergolas, handles, furniture, heavy construction, docks, bearings and more. It can also be used in both internal and external environments.

At the Modinex Group, our Cumaru range has got excellent machining results in a range of lengths and wider boards to suit your space and requirements. Talk to the Modinex Group about a customised finish and size; there are many options to explore.

Cumaru Species Guide

Cumaru Features & Benefits

Cumaru Hardwood Rating

Not only are Cumaru known for their durability and strength, but they are also recognised for their fire-resistant properties. Cumaru is suitable for use in bushfire rated zones up to BAL29, meeting the specified high density of AS3959-2009. This ensures in the case of a fire emergency; the timber uses a thermal breakdown process to insulate the inner core from catching fire and slow down the timber burning in a more predictable way.

Ensuring the timber used in your next project contains fire resistant properties act as another safety precaution to protect your structure from unwanted damages and is recommended for any project using timber product.

A Sustainable Resource

At Modinex all our ranges feature PEFC certified timber and this includes our Cumaru timber. This means the lumber is sourced from a forest that is managed and harvested sustainably to preserve the conservation of our forests.

Appearance & Grain

Cumaru timber first appears a reddish brown when freshly cut and turns to a uniform tan colour once exposed to the environment. Upon exposure it turns to a light brown which can add visual dimension to any decking solution. The Cumaru grain is interlocked of medium to fine texture which adds a point of visual interest to the timber.

Notably Cumaru timber has a negligible tannin bleed and near-zero leaching. Leaching occurs when the natural oils and resin from the timber are exposed to moisture and can cause rust-like bleeding marks of nearby surfaces. A near-zero leaching timber means the colour won’t leak and is a great choice to use near light-coloured surfaces.

Structure & Performance

Did you know Cumaru hardwood can last over 40 years above ground and over 25 years in-ground? Classified by the Australian Durability Rating as Class 1 durable timber, the Cumaru has the highest level of durability any wood species can have.

Cumaru is also naturally resistant to termites, insects and rot with great weathering properties making it a robust timber for decking, boardwalks, and other applications.

The Cumaru timber is also structurally rated at stress grades F34 for beams and F27 for posts.


Cumaru Hardwood Timber Technical Information

Physical Properties

Scientific Name Dipteryx odorata
Common Names Cumaru, Southern Spotted Gum
Regions Of Distribution Northern South America
Heartwood Colour Medium to dark brown, sometimes with a
reddish or purplish hue
Sizes up to 250 x 250
Lengths up to 5.7m
Natural Durability Class 1*
Radial Shrinkage
(Green To 12% Mc)
Tangential Shrinkage
(Green To 12% Mc)
Fire Rating BAL29


Mechanical Properties

Mechanical Properties Green Dry (12% Mc)
Modulus of Rupture (MPa) 132 188
Janka (kN) 14.8
Max Crushing Strength (MPa) 65 93.5
Modulus of Elasticity (GPa) 22.3
Specific Gravity (kg/m3) 780 820
Weight (kg/m3) 1280 1020

Cumaru Hardwood Timber FAQs

What is Cumaru?

Cumaru, also referred to as Golden Teak or Southern Spotty, is of the Dipteryx odorata species and is a heartwood known for its durability and integrity. Originally from South America, Cumaru is now grown across the globe for use in a wide range of architectural projects. Cumaru’s natural density makes it termite and rot resistant as well as bushfire rated with excellent weathering properties. It is most commonly used in external projects such as decking or exterior cladding. However, Cumaru’s versatility makes it a go-to choice for a range of different applications.

Is Cumaru water resistant?

Due to the high density and natural oils present in the Cumaru wood, it is somewhat water resistant on its own. This means the hardwood is unlikely to absorb water and moisture, making it a great option for kitchens, bathrooms, saunas and more. However, for added protection a waterproof finish can also be applied for further seal the wood and increase its longevity, particularly in high traffic areas.

How long does Cumaru wood last?

Due to Cumaru’s durability and density, the wood is known to last for an average lifespan of over 50 years. As a result, Cumaru is a great option to invest in due to its lower long-term cost.

Does Cumaru darken?

Cumaru does darken slightly over time, particularly when exposed to direct sunlight. However, this is natural for most hardwood species that are prone to photosensitivity.

Does Cumaru wood burn?

Cumaru is a species known for its strength and high-density, it is these characteristics that also makes the hardwood fire-resistant. With a low flame spread rating, Cumaru is suitable for use in bushfire rated zones up to BAL29.