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Can you advise a timber product that has a 100 year design life certification that can be used for internal timber studwork?

Woodsolutions Answer +

For timber, warranties are generally given in relation to a specific hazard. For example, preservative treated timber may be supplied with a warranty, or guarantee, that it will achieve a specific service life. In the absence of hazards such as termite attack, storm damage, water leaks and similar events, internal timber studwork has an unlimited service life. Indeed, there are historic timber buildings more than 100 years old that have escaped such damage. However, we don't know of any producers offering 100-year certification. 


Have an order for 200x175mm in sugar gum asking for F17. I can either cut it boxed-heart or cut through heart (but not excluding it) - like a sleeper cut. Always called this F-14. Am I correct? Would I be correct in thinking this size heart-free would be difficult in any sawlog to 600mm diameter? 

Woodsolutions Answer +

To make F17 grade, unseasoned sugar gum has to comply with Structural Grade no. 1 in AS 2082. In pieces where the smaller dimension is 175mm or more, this grade requires heart to be within the central one third of the width and thickness of the piece, so it would have to be boxed heart.


I had to remove a large yellowbox on my property in April 2017. Being such a large straight specimen, 1200 mm diameter trunk @ 16 meters long before the crown , I could not bare to turn it into firewood. I had it milled to various sections, all 7 meters long & have stored it correctly for drying. Controls from the milled timber were weighed & measured every month.

Now fully seasoned, I wanted to use it for structural timber in a building on the property. This will require compliance to local building codes. How do I go about getting the timber signed off for use & are there any independent inspectors or labs?

Woodsolutions Answer +

Your best contact in Sydney would be Timber Inspection Pty. Ltd. The NSW Forestry Commission used to do timber grading and inspections, but they closed the service and the inspectors formed a private company. You can find them on the net at this address: To find a grader in Melbourne you could contact Timber Training at Creswick. They have a website Since they run courses on visual stress grading they should be able to put you in touch with a timber grader. If you are located in some other part of the country, let us know and we may be able to suggest other qualified graders

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