barbie gee wrote:

the bath tub water spout/spigot has a pull-up knob to get water to the
shower head. it's not closing fully, and about half the water is still
bypassing the shower and ending up in the bathtub.

Is there a fix/repair for this?
or should I go and buy a new spout only? The fixtures are only 10 years
old, so I'm surprised it's failing already...

I'm good at DIY, so I'm willing to fiddle a littlw with this..

In general, they are not repairable. Get another.
You'll need to get the old one off first to get an exact match
as there are several types. Some have a setscrew underneath
and slip on; others have pipe threads.

If it's threaded on, there is some risk of twisting the pipe,
especially if copper. If there is an access panel so you can
see behind, have a helper watch as you unscrew the spout.

Use teflon tape on the threads and be sure to caulk the spout
to the wall.

Jim