I was chuntering and mumbling a while back about someone installing a shower
tray with all solvent weld where I could get at it, and a final compression
joint under the tray where I could not.

I ended up chopping the tray up to get it all out.

I then found, working my way back up the pipework, that most of the joints
were loose.
I think they were all solvent weld, although my first thought was that the
installer had used silicone sealant one one joint to allow it all to be
taken apart again if required.
There were signs of water getting out of the joint (dirty marks on the
plastic pipe and the elbow all the way to the edge) so it looks as though at
least one joint had been dodgy for some time (if not its entire life).

So, how long should solvent weld last?
I assumed it was good for the life of the pipe but either this was a bad
install or there is a limited life on solvent weld joints.
I think the installation is betwee 10 and 20 years old.

Cheers

Dave R

P.S. I have reinstalled with solvent weld, but I have used a 'proper' shower
trap which unscrews from inside the trap from the top, and allows you to
remove it with the trap in situ and the shower tray also in situ.