What is the minimum depth of lead in a joint when making a lead and oakum joint on bell and spigot pipe?

When making a lead and oakum joint on bell and spigot pipe, the minimum depth of the lead is crucial for ensuring a watertight seal and adequate strength of the joint. A depth of 1 inch for the lead ensures that there is enough material to fill the joint effectively, allowing it to expand and contract without compromising the seal. This depth helps prevent leakage and provides the necessary support to maintain the integrity of the pipe connection under various pressure conditions.

A depth of less than 1 inch might not provide sufficient coverage, risking the effectiveness of the joint. It could lead to improper sealing and increased vulnerability to leaks or pipe failure. Therefore, the requirement for a minimum of 1 inch is set to guarantee a reliable and durable lead and oakum joint in plumbing and drainage systems involving bell and spigot pipes.