Leak under shower tray

[Aluminati]

It’s bridging the cavity, so any pipe connection passing through would be my first port of call. Get a boroscope in the cavity.

[James6112]

That big block on the outside wall, was that related to the shower fit?
Wonder what’s behind there!

The shower sits into the floor it seems, I wonder if there’s some connection behind that block?
Otherwise, where does the shower waste go

[OutInTheShed]

Aluminati said:

It’s bridging the cavity, so any pipe connection passing through would be my first port of call. Get a boroscope in the cavity.

Looking at the 'quaint' brick pattern, is there a cavity?

Water will run a long way along the outside of a pipe sometimes.

Someone up thread raised the concept of the tray itself leaking.
Duct tape over the trap and fill with water, see if it leaks?

I would be pretty keen not to remove the tray if possible, so time spent investigating might save a lot of cost and carnage.

Borescope is a good call. Might be able to look under the tray somehow, even if it means drilling in from outdoors.

[Rollin]

Are there ways of reline above ground waste pipes as there are underground drains?

[billbring]

An update...

I exposed all the pipework in the wall and have discovered a leak on the cold inlet at the point it joins the valve.

For anyone interested, here's a little video of the leak and you can see how fast it's dripping.
https://streamable.com/qyuyfn

I can isolate it in the loft above so have left it alone for now.

Unfortunately, I still believe there could be a leak on the waste pipe as well, given that the outside damp patch looked considerably worse immediately after using the shower, whereas the leak on the valve would have been constant.

The plasterboard behind the tiles is all rotten anyway, so it will have to all come off and the shower tray also has very slight play in it which rocks maybe half a millimetre if you stand in the right place. No doubt caused by water damage, and I find it generally annoying so another reason to take it up and get everything re-done properly.

[Aluminati]

Speed fit buried in a wall . Not for me.

[Wacky Racer]

Might not look as pretty, but I would much rather have water pipework exposed (Where possible) rather than have to rip out a load of lovely tiles, which may now be discontinued or unavailable.

[No ideas for a name]

Aluminati said:

Speed fit buried in a wall . Not for me.

What is the chance that the leaky pipe hasn't had a pipe support/insert?

[billbring]

Agree that Speedfit buried in a wall isn't ideal, but that's not where the leak is. It's at the joint of the control valve.