My house is about 20 years old and has poly B pipe for the cold and hot water,in less then two years it leeaked twice,all happened in hot water pipe close to the hot water tank.I was told poly B pipehassomany probleit was discontinued long time ago... it will cosr me $7000.00 if I hire some contractor to change the pipe for entirehouse... so I wonder if I could do it myself..

I believe a homeowner should have the right to do his own work. Whether YOU can or not is up to you. You have many options in material to work with. Copper, CPVC, Pex, Galvanized. What are you comfortable with? Do you have to replace waterlines in walls also, or just exposed ones? Basement, crawl space, or slab? Ranch, trilevel, 2 story? Lots of questions to answer before you decide whether to tackle this yourself or call in a professional.