Cast iron waste pipes are normally limited to the lines that are 2" and greater. The smaller 1-1/2" and 1-1/4" lines are more likely to be galvanized iron pipe, brass pipe or copper pipe. True cast iron pipe with oakum and lead joints is almost a permanent fixture, often outlasting the structural materials used to construct the house, so I would not worry about the actual cast iron pipes. Galvanized iron pipes are notorious for rust and scale on the inside of the pipes that leads to excessive clogs and they commonly rust through at the joints where the zinc coating was cut away during the threading process. Thinwall brass and copper DWV (Drain, Waste & Vent) pipes often develope leaks on the underside of the pipes from grooving which is caused by acids which are present in all waste lines. If you have the walls open and accessible I would recommend you seize this opportunity to replace any galvanized iron, brass or copper DWV piping with ABS or PVC. If you have galvanized iron pipe water lines I would highly recommend replacing as much as possible. Just make sure that if you are using copper pipe to replace sections of galvanized iron in order to prevent electrolosis you may not directly couple copper to iron pipe. You may make the transition by means of a Dielectric nipple or a 6" hardened bronze nipple between the two materials.

ten years isn't that new for a kitchen - are the countertops that worn? If you're going to spend on counters, personally I think it's unwise not to do the whole kitchen...unless the counters are really bad. On reflection, the choice you are asking us is kind of, umm foolish. It's like comparing apples to oranges. I agree, many people choose homes on stupid things like gold taps, and overlook other things.. However, somebody who replaces countertops and leaves gal pipe, is going to give the impression when they sell, they're doing cheap and nasty and may make people think you're covering other flaws up. OR, to quote an old saying, penny wise, pound foolish. If one of those pipes fails in that three years - and, you never know, you may decide to stay longer - things change - you will be faced with potential damage and may need to remove those countertops to replace the pipes that should have been done, and the granite could well break in the process. In the kitchen at least, the time to do the pipe is when the counter's off....so you should seriously consider doing both. There is really no logical answer to this question that makes sense. If you want to sleep soundly at night, and feel confident you can go away for a few days, replace the pipes.

I was quoted $ 2500 for similiar work. My uncle made the referral. Meanwhile the same plumber retiled his bathroom and fixed a leak whick took about 3 days. All material was included in the price except the tiles. The price was much less and more labor intensive. You gotta watch those plumbers! nyc.

"Is it necessary, or a good idea to replace the areas of the house that were not included in the remodel, since the house is 25 years old since it is M copper?" Yes, do a total replacement, as the copper has reached it expected life expectancy. CPVC is widely used in mobil homes due to it's flexibility and lack of out-gassing at the glue joints. "Also, the plumber wants to use several island vents, including one in a bathroom. He doesn't want to go through the roof." You need to have a short and serious chat with your contractor about quality of workmanship, because this is BS. "And yes I think this is all about the general contractor saving money, my husband is afraid that if we push him too hard about the pipes he will charge us more on change orders/items that he has completed, but will not give us a price on." In many states all change orders are required in the business and professional code, to be fully priced upon presentation for signature. But, why would you sign an authorization to proceed, without knowing what it cost? "We ask him how much adding or changing something will be, instead of telling us he just builds it without giving a price or change order. We have asked him several times to write it up, but he does not, Its really irritating and yes my contract states that he must give us the change order in witting, before he changes anything." If you know an attny. better yet where he lives, don't wait until monday, race over to his house and break in.