I noticed that in the 2011 NIV, Job 28 is marked off as an interlude as does not appear in quotation marks; whereas in the 1984 NIV, the text appears in quotation marks and is considered a part of Job's final speech. I can see how 29:1 might recommend the 2011 approach. Should this passage about wisdom be considered an interlude by the narrator? If so, why might the narrator choose to place it there?
My Jerusalem Bible interprets Job's speech in chapter 27 as ending at verse 12. It assigns the rest of chapter 27 to Zophar (via the paragraph heading "The speech of Zophar: the accursed"). When it gets to chapter 28 it makes a major break with a chapter heading that says "D. A HYMN IN PRAISE OF WISDOM" and follows this with the paragraph heading "Wisdom is beyond man's reach". The entire chapter is set as three stanzas of verse. The end of the chapter has another major break and the chapter heading "E. CONCLUSION OF THE DIALOGUE" introducing chapter 29.
The Jerusalem Bible, then, does not attempt to assign chapter 28 to any of the characters making speeches in Job. It breaks chapter 27 after verse 12 based upon a change of subject and tone from Job's defensiveness to accusative content. It assigns the accusative content to Zophar because Job's other two accusers have already had their say in this round of the conversation.