The 2009 edition of AS 3959 didn't deal with verandah posts. It was illogical to provide for a verandah roof, but not the posts that support it, so clause 5.7.5 was added in the 2018 edition covering verandah posts in BAL-12.5 (clause 6.7.5 in BAL-19). The wording is somewhat confusing. The clause requires posts to be mounted on stirrups not less than 75mm above adjacent ground level, or to be made from certain timbers if less than 400mm from the surface of a deck or ground. The reference to posts "less than 400mm....from the surface of the deck or ground" seems to be a drafting error.

If the pole is hardwood the creosote has most likely only penetrated the outer band of sapwood. Theoretically the sapwood could be sawn off, leaving a square of clean timber that could be re-sawn into smaller sizes if desired. However, in practice there are a few unknowns. The main issue is that although penetration will be largely confined to the sapwood, creosote will have penetrated more deeply via any cracks that were pre-existing in the wood at the time of treatment. Also if the pole is softwood, penetration is likely to be deeper.

Your timber trusses can be visually stress graded in situ as long as access is available and all surfaces are visible. Australian Standard 2858 contains grading rules for softwoods, and Australian Standard 2082 for hardwoods. We don't have a contact in the Newcastle area but we suggest you contact Timber Training at Creswick.