How to handle a leak

[Theogenes]

I live in a 3 year old house. This is our 3rd winter in the home and the 3rd straight winter we have water leaking into our family room through an attic hatch. There is obviously water, most likely snow, coming into the attic, then from the heat of the home, melting and coming through the attic hatch, dripping onto my furniture. This is the 3rd year in a row. The builder keeps sending out his useless lackeys to stare at it, but nothing ever gets fixed. Now we are worried about the possiblility of mould and the strength of the drywall.

Is this a legitimate legal matter now? Should I contact a lawyer to get this builder to move on it. My wife and I both believe three years is more than enough patience on our part.

Any information would be greatly appreciated.