What is the minimum depth of tamped earth that backfill must be covered with over pipes to avoid damage?

To ensure that pipes are adequately protected from damage due to backfill, the minimum depth of tamped earth over pipes is specified as 12 inches. This requirement is based on the need to provide sufficient weight distribution and reduce stress on the pipes from surface loads and impacts. When backfill is compacted to a depth of 12 inches, it minimizes the likelihood of settling and reduces the risk of displacing the pipes, which could lead to stress, cracking, or other structural issues.

This depth is crucial because it not only supports the integrity of the buried pipes but also helps facilitate proper drainage around them, preventing water accumulation that could lead to erosion or other soil-related issues. The standards outlined in the International Residential Code emphasize the importance of this specification to maintain the long-term functionality of plumbing systems in residential settings.