Case 2

Water Leakage at Floor Traps

Introduction

Type of Building: Residential

An “S” trap” made of cast iron is illustrated in the figure. In this case, water is leaking through the pipe penetration and the joints as shown. Short gully pipe was observed and identified as the main source of water leakage.

Rust which is a by-product of corrosion process, was observed closer at the pipe joints. Corrosion is inevitable in any iron-based material such as cast iron, when they exposed to moisture and oxygen. Rust inhibitors are generally used in plumbing system to avoid corrosion. However, with damage of the protective film as in this case, corrosion process is unavoidable during the service life.