What is the maximum horizontal spacing for supporting cast iron pipe?

The maximum horizontal spacing for supporting cast iron pipe is 5 feet. This specification is established to ensure the stability and integrity of the piping system. Cast iron pipe is relatively heavy and can easily sag if not adequately supported, which could lead to stress and potential failure over time. Proper support helps maintain the alignment of the pipe, reduces vibrations, and prevents cracking or other damage that can occur from excessive spans between supports.

When designing installations, meeting these spacing requirements becomes crucial for improving longevity and performance. If the spacing exceeds this recommended limit, it increases the risk of structural issues developing due to the pipe weight and external forces acting upon it. This guideline is commonly referenced in plumbing codes and standards to promote safe and effective plumbing design.