The repair of my sagging ceiling went well over the weekend. There
were 2 connected 4x8 sheets that were the problem. And to make
matters more complicated, one of them was over a stairwell. Luckily
there was NO insulation under the rafters/joists since the original
builder stapled vapor paper (almost like thin package wrapping paper)
to the joist channels. This kept the insulation between the joists.

In addition to the 5 or 6 2x4s keeping it supported all week, it
became obvious that trick was to put more poles down a joist line
every 12" or so with 1 or 2 on each side at the next joist. I had
enough wood for about 3 or 4 in a row. Starting at one end, I wedged
the drywall up, put in 1 or 2 screws every 8-12", them moved the back
pole around to the front of the row. Put in another screw or 2,
repeat. This REALLY turned into a challenge over the stairwell since
every pole had to be a different size. The largest one was about
14'.

It took awhile but everything seems to be holding. I'll wait abit to
spakle so I can watch the bare screwheads for signs of sagging.

Thanks to all for the advice and suggestions. If it holds for another
20 yrs, I'll be very happy. The lesson learned for me is not to
ignore possible warning signs. The job wouldn't have been so
complicated if I fixed it when the sagging first started.

--Jeff