On May 16, 1:32*pm, John wrote:
It seems that I have a single pair of joists which bow upwards. *Thus,
they are 1/2" different in height than the joists on either side of
them (so 1/2" in about 5').

Not sure if I understand correctly, so I'll throw an idea out there.
It's probably the opposite of your situation, but someone may find it
useful.

I had a problem in my kitchen where two adjacent joists were
significantly higher than the surrounding joists. We were replacing
vinyl with hardwood, so a flat floor was a requirement. As it was,
pressing a 4' level flat on one side of the hump left a good 3" gap
under the other side of the level.

Rather than remove the subfloor, we cut vertical slits in the joists
from below. Cuts were made every 2' or so, about 75% of the way
through the joist. Applying some pressure from topsides (i.e. me
jumping on the floor), we 'cracked' the joists until the floor was
basically flat. The next step was to sister two new joists to the
existing, and the problem was solved.

Well, not quite that simple...I had to disconnect a good 50% of my
electrical panel, as a good portion of the wires were running along
those joists