What is haunching in relation to pipes?

Haunching refers to the first layer of backfill that is placed above the bedding in a pipe installation. This layer is critical because it provides support and stability to the pipe, ensuring that it is properly positioned and protected from external loads. Proper haunching helps maintain the alignment and integrity of the pipe, reducing the risk of damage from soil settlement or movement over time.

In contrast to the final layer of backfill, which is completed after the haunching, or insulation which is not related to the backfill itself, haunching specifically addresses the initial support setting for the pipe. Additionally, it is not a seal around pipes, as seals serve a different function related to preventing leaks and maintaining the integrity of the connections between pipes and fittings. Therefore, understanding haunching as the initial supportive layer above the bedding is essential in ensuring the long-term performance of the piping system.