What Happens Inside an Aging Galvanized Drain Line
Galvanized steel drain pipe corrodes from the inside out. As the zinc coating wears away under repeated exposure to hard water, the steel beneath corrodes and develops a rough, pitted interior surface. Unlike a smooth copper or plastic drain line, this roughened surface creates thousands of small surfaces for grease, soap, and mineral deposits to bond to. The pipe also narrows as corrosion reduces the interior diameter over time. The result is a drain line that clogs faster, clogs more completely, and resists clearing more stubbornly than a newer pipe of the same diameter.
For Boulder City homeowners in historic homes, professional drain cleaning every year rather than every two years is often necessary to maintain adequate drainage. When a video camera inspection reveals significant interior corrosion, re-piping the drain lines may be the more practical long-term solution than repeated cleaning.

