Is the damp/wet the result of a relatively recent repair, and just needs to dry out, or a leak from the copper pipe?
Only if you are ready to repair any damage to the clay soil pipe that might well result, or have someone on hand who can do this and fit a plastic to clay pipe adapter.
for now I've shoved a tissue under the water pipe, will see if this stays dry.
Signs of damp - ground a bit wet, corroded pipe, and some woodworm on a joist.
This is possible cause.
Should I break up and see?
In your second photo - It looks as if the right hand timber might have rotted out and been replaced in the past, judging by the supported joint.
So, how do I do the leak test? I assume just shove something in the drain outlet and fill the drain to the top and watch?
What is a big drain plug called, where can I get one delivered from quickly? I might need to pop to Wickes this week actually
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