Should plumbing lines be replaced during a bathroom remodel?

The decision framework: material era first, since certain vintage supply materials carry documented failure patterns and earn proactive replacement wherever exposed, while modern piping in good condition earns inspection and continued service; evidence second, corrosion at joints, mineral narrowing, past leak repairs clustered on one run, and any shutoff that will not turn are the room's own testimony; and opportunity third, because open walls convert repiping from drywall surgery into stapling, and the exposed-section price will never be lower. Shutoff valves are the universal yes: aged multi-turn valves seize exactly when needed, and quarter-turn replacements cost minutes during a remodel.

Scope honestly by exposure: the remodel opens this room's walls, so this room's runs are the candidates, with whole-house repiping a separate decision the inspection may inform but the bathroom budget need not carry.

Replacement cost divides into access and plumbing, and the remodel already paid for access: exposed-run renewal prices at licensed hours plus material, while the same work post-remodel adds demolition and finish repair that typically dwarf the pipe. This asymmetry is the whole argument for deciding now, with the walls' contents in plain view.

The risk ledger favors action at the margins: a vintage supply line behind fresh tile is a deductible waiting to activate, while over-replacement of sound modern pipe is money converted to nothing. The framework exists to find the line between them.