My upstairs ceiling has always had cracks between the boards - not helped
by being so close to the West Coast Main Line! Now that the line has been
'upgraded' and the lines have rubber pads under them, it seems to be worth
having [another] go. My father spent years trying to seal the cracks, so in
some places there's a build-up of whatever he used.

I bought a box of dry-wall screws (38x3.5) - having 1000 of 'em I'd like to
use a few.
Tried running some in with the portable drill; went in OK, stopped just
below flush but the edge of the board cracks. Also the joints aren't all
central on the joists, so there could be 3 - 4cm one side and 2 - 1cm the
other.
Before I perforate the whole damned sheet, please advise me on how to do
this. If necessary I'll drill and c/sink the holes.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.