Do we have legal recourse against contractor/subcontrac. after living in home for 3 yrs?

I have lived in my brand new house for 3 yrs...and have had problem after problem with plumbing leaks. Since i moved in permanently in 2010 I have had to call a plumber for leaky pipes 5 times and counting. I called the contractor after the first leak and he told me he was done with this house after his first year since I bought it in 2009 and couldn't help me.

My question is: can we sue him (the contractor)or his plumbing contractor for defective plumbing? and if so what kind of attorney would I need? I was under the impression that when we close on a house we give up the right to sue for defects...don't know what to do.