What type of copper piping is most commonly used in residential homes?

The most commonly used type of copper piping in residential homes is Type M, which is indicated by red ink. Type M copper pipe is thinner than Types K and L, making it lighter and easier to handle, while still being sufficient for most plumbing applications found in residential settings.

Type M is often used for both hot and cold water supply lines, as well as for heating applications. Its cost-effectiveness and ease of installation contribute to its widespread use in home construction.

In contrast, Type K features thicker walls and is typically used for underground installations or in areas where high pressure is a concern, making it less common in typical residential plumbing. Type L, while also thicker than Type M, is primarily used for more demanding applications and can often be found in commercial installations. Type R is not generally recognized among standard copper piping types; the most relevant types are K, L, and M. Thus, Type M’s balance between durability and cost makes it the preferred choice for residential projects.