Product in Focus | Cumaru Decking, A New Durable Hardwood

This month's Builder's Bulletin bowens.com.au magazine, our feature article looks at a replacement timber decking project using a new versatile and durable hardwood that would be new to most readers called Cumaru from Porta, sourced from Peru.
The project involved replacing both the front and back decks of a renovated Victorian house in the inner suburb of Richmond. The home owner, Claire Greenwood explains that; “My old deck was made of Merbau, which was getting old and needed replacing. I wanted something with a more modern look, something that would add a bit of wow factor as well as value to the property.”
Lyle Maybury, National Commercial Sales Manager at Porta says that Cumaru is a highly durable timber from Peru in South America and is sourced from FSC certified forests.
Porta has always been a strong advocate of sustainable logging. They visited the forest and the mills in Peru themselves to personally verify the timber source was legitimate.
Cumaru, also known as Brazilian Teak or Tonka, is a very hard-wearing timber. Its high density (1085kg/m3 dry) means it meets the specified density in AS3959-2009 for construction in bushfire zones up to BAL19.
Lyle explains that; “We selected Cumaru because of its versatility and its durability. Its ability to be used in a wide range of applications, both internally and externally is a key feature.”
Frank Di Stefano, the timber specialist at Bowens says that decking, being an external product, is often plagued with many problems. When Frank first found out about Cumaru, he saw an opportunity to test the workability of the product and see how it could be used in a deck situation.
Damien Collins, Managing Director of Project Logic was approached by both Bowens and Porta to take on the Richmond deck project and use the new hardwood timber for the first time. Everyone involved was keen to see how Cumaru could be used and how it would compare against traditional Australian hardwoods.
The carpenter who worked on the project, Ben Chadwick, said that Cumaru was a very clean and easy timber to work with, especially when compared to Merbau. He said, when using Merbau, you must weather the timber and allow the tannins to leach out. This adds extra time on the project as well as the risk the tannins leaching onto surrounding surfaces such as around pools or courtyard tiles.
Ben commented that; “With Cumaru, you don't even have to worry about the sawdust settling on pavers and leaving it overnight. Overall, Cumaru was just a lot easier to use and I would be very happy to work with it again.”
In fact, Porta has carried out extensive tannin bleed tests with Cumaru and the results were negligible.* Ben adds that Cumaru could be very useful for window sills where bleeding is often an issue.
One of the most appealing things about Cumaru is that it has an interesting grain pattern and colour. Damien says that; “because of the interlocked nature of the grain, it catches the light in different ways from different angles. At any one time, you get a different perspective on the timber.”
Damien further explains that; “Porta supply a nice wide thick board. It provides very good coverage and there was zero waste. We had absolutely nothing to throw away on this job. There were no knots in it, there were no problems.”
Narrower 90mm boards where used on the front deck because of the smaller space. On the larger rear deck, wider 145mm boards where used. Cumaru can be pre-oiled in the factory and is also available in beams and posts.
The fact that Porta can mould any profile in their factory, such as claddings, lining boards and handrails, means there can be a seamless flow of timber throughout a house. It is possible to match all trims and mouldings with the cladding, decking, and flooring which makes Cumaru a unique and attractive timber.
“We're really excited about using Cumaru from the inside through to the outside. The longevity of outside is going be fantastic; on a deck or around a swimming pool for example. We're really comfortable with using it on future projects,” says Damien.
Frank says; “Having the opportunity to stock an innovative timber like Cumaru gives us the option to offer an alternative to our builders.”
To find out more about Cumaru, visit a Bowens branch, talk to your account manager or visit either bowens.com.au or porta.com.au
Bowens, the Builders Choice, is a Victorian family based company that has served the building and construction sector since 1894. Bowens has 13 branches including Melbourne's largest under cover timber yard at Port Melbourne.
* Compared to other hardwoods tested Cumaru demonstrated no apparent or negligible bleed. However, Porta recommends cleaning of timber prior to installation and a suitable sealer to protect the timber and minimise any potential run off of natural resins onto surrounding surfaces.

[@tomekapompey563]

Enjoy woodprix woodworking instructions.