When the column is not the one on the drawing
A substitution nobody wrote down.
In short: A steel column whose size and specification did not match the engineering, found at frame.
What we recorded
A column on an Austral frame that was not the section the drawing specified, and separately a connection built differently to the engineer's detail.
Why substitution happens
Availability, usually. A yard has one section and not another, and the swap gets made on site without anybody going back to the engineer.
Why it is not a small thing
The engineer chose a section for a load and a span. A different section has different capacity and different stiffness, and nobody on site is in a position to say the swap is equivalent.
The paperwork point
If a substitution is genuinely equivalent, the engineer will confirm it in writing. That letter is what should exist, and frequently does not.
Timing
Frame stage, while the steel is exposed and the fabricator is still engaged.
Written by the Owner Inspections team from inspections carried out in Austral. Licensed building practitioners, NSW Fair Trading licence 366177C.
