Which type of copper pipe is most commonly used in homes?

Type M copper pipe is the most commonly used type in residential plumbing systems. It is preferred for several reasons, including its balance of strength and weight, which makes it easier to handle and install. Type M is thinner than Type K and Type L, allowing for better flexibility and ease of use in various plumbing applications, such as water supply lines.

The color coding helps in easily identifying the type: Type M is marked with red ink. While Type K is suitable for underground installations due to its thicker wall and corrosion resistance, Type L is often used for areas that require increased durability or in settings where higher pressure is expected. In contrast, Type M is adequate for general household needs and is widely available, which contributes to its common use in homes.