Rising damp...

[MrMark]

I like the title of this thread. I have to admit it made me think it referred to the C̶o̶c̶k̶m̶o̶u̶t̶h̶ Cumbria flooding.

[DimPrawn]

So how many bathrooms did that take you up to? Was it 8 or 9?

Do I include the outside bog?

[EternalOptimist]

"The derivation is unknown. What we do know is that the term has nothing to do with the UK slang term for German - Jerry/Gerry. This is of WWI origin and the citations above pre-date that. As always when a phrase's origin is unknown people like to guess, so here goes. It is possible that the term derives from the slang term jerrycummumble or jerrymumble. This was defined in the 1811 version of Francis Grose's Classical Dictionary of the Vulgar Tongue:"

http://www.phrases.org.uk/meanings/211600.html

I disagree

There was a type of ad-hoc repair used in the navy , known as a 'Jury-rig'
Everyone who watched 'HornBlower' knows this,
It probably derives from this

[DimPrawn]

I thought it referred to Jericho. As in the walls came tumbling down. Jerry built.