It is unfortunate that Regulatory Information Report 41117.10 includes an extract from BCA 2019. This extract was included to help specifiers, but with the issue of BCA 2022 gives the impression that RIR 41117.10 is out of date, although it does not expire until 31/3/2024. We suggest you disregard the BCA 2019 clauses included in RIR 41117.10 and refer your certifier to the fire hazard data. Clause S7C4 on page 154 of BCA 2022 requires fire hazard data to be assessed as follows:

The timber appears to be seasoned hardwood, eg. Vic ash. If supplied as visually graded material, to achieve F17 stress grade it would need to comply with the grading rules for Structural Grade No. 2 in AS 2082, Timber - Hardwood - Visually stress-graded for structural purposes.

The grading rules for recycled decorative products and recycled structural timber are separate documents but were part of the same project and have the same Project Number, PN06.1039. However, they can be differentiated by title, namely Visually Stress Graded Recycled Timber for Structural Purposes, and Visually Graded Recycled Decorative Products.

The 100 x 100 pine treated to H4 level will be protected against wood rot and insect attack. The LVL treated to H2S level will be protected against termite species found south of the Tropic of Capricorn, hence the 'S' designation, but not against wood rot. However, termite attack on the 4th floor, with the timber seated on a concrete slab, is somewhat unlikely. Wood rot is highly unlikely since decay-causing fungi, including so-called "dry rot", require a source of moisture, and the existing slab will presumably be dry if it has been in place for a significant period of time.

Span tables for LVL are published by the producers. At WoodSolutions we haven't published tables of our own. However, it's possible that one of the software design programs available from our website could provide an answer. Various programs can be accessed via this link https://www.woodsolutions.com.au/resources/specifications/span-tables-and-software. Failing that, we suggest you contact an LVL producer or a consulting engineer.

We are not aware of the use of Eucalyptus grandis for CLT, but its general properties can be found on our website via this link https://www.woodsolutions.com.au/wood-species/hardwood/gum-rose. It is known in Australia as "rose gum". Cusp Building Solutions in the State of Tasmania produces CLT from another plantation eucalypt, Eucalyptus nitens, known as "shining gum" so it seems likely that E. grandis would also be suitable with appropriate testing.