Thanks tweeze, I need it.
I'm 'not happy Jan' - I've got 5 holes in my wall a no leak to be found. Low and behold, the plumbers now gone to get a brick saw to he can cut the porch slab to see if the leak is under the house slab after all
All this after I asked him if it was worth looking under there in the first place, when I questioned that maybe the flow noise we could hear was being transfered. Hmmmmmmmm.........