We live in a Victorian semi with a porch and front door on the side. Decided to extend the porch to run the length of the house so that we could better use the space for storing buggies, bikes etc.
Got a cheap ish builder who built a wooden frame on top of a wall that we shared with the neighbour, popped roof on and out a new door, frame etc on the back.
We they had it plastered. Noticed that a couple of sections on the old 'wall' didn't dry but we painted it anyway.
Paint is now flaking off, dusty mould growing and it smells of damp (well it did after the recent rainy bit).
Resigned to the fact that the wall was clearly damp (hadn't suspected this as neighbour has also extended their porch). Will it dry out or do we need to think of something else? Builder we used was, in hindsight, crap. So loathe to go back to him and waste more money. Still haven't put new floor down but need to soon.
Humph 
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