Lead Coated Copper & Cast Iron Piping Issues

Copper Issues

• The main problem with copper piping, whether or not it is coated with lead, is its tendency to pit. When pits form inside the pipe, they eventually deepen and enlarge into pinholes that allow water, or whatever else may be carried through the pipe, to leak out. Copper pipe is often used because of its overall resistance to corrosion, but even copper is not immune.

Copper Pitting

• Copper pits when it is used to transport hard water with a pH of 7 to 7.8. The addition of the water being very cold hastens the corrosive effects. In addition, pitting may also happen in water with a lower pH if the water is soft. Higher temperatures, such as above 140 degrees Fahrenheit, may also hasten the damage. Soft water with a pH higher than 8 also causes pitting, but results typically in pipe blockage or water discoloration as opposed to the complete pipe failure caused by the other two circumstances. Using a water softener and monitoring the pH of your water can extend the useful life of copper pipes.

Cast Iron Issues

• Overall, cast iron is a worry-free piping material. The strength of the material translates into quieter pipes, unlike lighter-weight or more expansive materials that are subject to movement under stress, resulting in banging, cracking and rubbing noises while in use. Cast iron is, however, subject to some rust and corrosion. Iron pipes are often more expensive to repair when problems do arise. They also experience pitting and pinholes and are more likely to suffer damage from the effect of corrosive gases, such as in the case of sewer pipes.

Cast Iron Corrosion

• The first sign of problems in iron pipes is spreading rust blisters that usually appear over the top of the pipe's exterior. These blisters indicate there is more extensive damage to the pipe's interior. Some iron pipes are weakened during their manufacture by a process called annealing. During annealing, the material is repeatedly heated and cooled, and if the pipe is not annealed enough, it remains weak and subject to corrosion and cracking. They also have issues with weakening along the seams, allowing content leaks and places for rust to get a foothold.