Why is it important to replace the pipes in an old home with copper plumbing?
Call a licensed plumber and have him or her explain the PEX plumbing system. That stuff is great. Flexible and indestructable. It can even freeze with no damage to the pipe. Most new homes I wire for electricity, are now being plumbed with PEX pipe. It is much better than copper, iron or PVC.
It's only important if there's something wrong with the old piping. If a house was piped with galvanized water pipes 60 years ago, the piping is very likely to have rusted internally, and will not deliver very much water (ie you flush the toilet and scald the person taking a shower). It's just worn out. If left long enough, it will get rotten leak break, but most people will deal with it before it gets that far. Lead may have been used in the galvanizing process in some cases. The water can be tested for lead, among other things. Search for water testing service. And depending where you are located, copper is not the only choice. If the pH of the water is too high or low, you would be better off with either PEX or CPVC. Acidic water can cause pinholes in copper pipe.
I've never heard of any entity government, local or federal that recommended replacing OLD metal piping with new copper pipes. To a great extent, the longevity of any pipes, other than plastic, like the new PEX stuff, is quite dependent on the quality or lack thereof, of the water in your particular area. I live in a house built in 1904, and most of it is still using good old galvanized pipe to supply water all over the place. We have plenty of pressure and flow out of both the old and the newer pipes which have been installed in the last 10-15 years. In the 40 years I've been working with plumbing, I've only seen two galvanized pipes that had rusted through to the point where there was actually a hole that leaked water. I have, however, seen a hundred copper pipes, most of them in walls, that have corroded small little pin prick holes in them and then sprayed all over the inside of the wall pocket between studs. That makes a mess of drywall and basement ceilings if they're finished. If you're seriously considering replacement of your pipes, I would very much recommend the new PEX materials. It's flexible enough to be installed very easily in places where pipes previously dared not go. I believe it's also less expensive than copper, by a bunch.
