I had a basement bath remodeled and the guy used all cpvc for the water lines (he's from California and is a real believer), including the fitting that the gooseneck screws in to. As this fitting is inside the wall, how do I connect the gooseneck where a plumbing leak won't be a potential problem, since the connection will be inside the wall? By the way, I'm a complete novice when it comes to plumbing. Thanks in advance, Bill