Don't think the chandelier caused the joist to sag, some upon drying do tend
to crown extremely, sometime down as you have, and as one in my house did,
it went up creating a hump in the floor.

If the ceiling is drywall, you would be better to remove a 4 foot strip
along the joist so that you can examine the whole joist. A plumber at some
time may have hacked away all the strength when he was working in the area,
at least you can then see what perforations there are in the joist. I would
not leave it as it is as you will notice it from below every time you walk
by. Fix it by sistering another joist, maybe one size smaller on each side
if vertical clearance is a problem and cutting the old joist to push it up.
Only by opening up the ceiling can you know what you can fit in there, and
what pipes are in the way and may need moving either permanently or
temporarily. While reno-ing the bathroom this is the time to fix it all.

This happens to me all the time, a relatively simple job snowballs into a
major change in multiple areas.

wrote in message
...
I am a novice DIYer who is renovating a second floor bathroom. I
removed the subfloor to move some pipes and now that I am ready to
relay the subfloor I have discovered that one of the joists ( which
are 16 inches apart) and which is in the centre of the room has sagged
an inch. It has sagged where the first floor chandalier was attached.
I removed the chandalier and tried to pull up on the joist but it
won't budge.I am limited as to how much I can push up on the joist
from the first floor because I dont want to disturb the finished
ceiling.

When I lay plywood across the joists there is an inch gap between the
plywood and the one joist. I could proceed and screw the plywood down
and then use a levelling mortar to fill the trough, or I could place
shims on the top of the 2x10 joist so that the plywood would lay
flat.What would be a good material to use as a shim? or how would an
expert proceed?
Brent
Thanks