Got up fiendishly early for the builder - the work will be done the week after next, and cost £700 ish. The surveyor never mentioned the evidence of the leak, which is very obvious, and I would certainly have haggled the house price down a bit if I had known about it. It had a bodged repair, and an attempt to hide it. But a surveyor should have seen it.
And I have pulled my back while carrying stuff up the stairs.