Damp on party wall

S1srs84

I have just had a damp proof membrane fitted along a party wall. 
Unfortunately I didn't know anything about party wall acts. 
Should of had one before the work started?
And what could be the outcome if my neighbour decides to get awkward? 

Doozergirl

You can attach onto the party wall without an agreement, it isn't structural.  

However, whether the DPM is the right thing to is a different question.   Whatever your issue is, you're likely to create a problem that shows next door. 

A membrane doesn't stop dampness occurring, it's the equivalent of a raincoat.  The water is still there and it will want to go somewhere - probably
out through the wall next door instead.  Depends on the problem.