Cast Iron vs. Copper Water Pipe

Cast iron and copper water pipe have always had their advantages and disadvantages. Their use for plumbing systems is often decided based on cost, ease of installation, and compared longevity of each metal. The use of one over the other can also be determined by local building codes.

Cast Iron

This metal has a long history of use in residential and commercial buildings over the past two centuries for the transport of mainly wastewater. In recent years, it has become the most economical choice due to the rising cost of copper. Concerns about the lead content in cast iron have become a drawback, however. Extra measures need to be taken during plumbing system installation to prevent the pipes from corroding.   


Copper pipe has become more expensive, but one of its main advantages is that it is quite easy to install with common household tools such as jigsaws and pipe-cutters. Pipes are available in two different types: soft copper for repair jobs and hard copper for standard plumbing systems. They also come in a wider variety of measured diameters, allowing for greater flexibility in use of pipe fittings. The measurements are referred to as Type K (thick), Type L (medium), and Type M (thin). Copper has also shown to be more resistant to rust, wear, and corrosion.