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Do Clogged Pipes Cause Water Leakage?

Tuesday, December 17th, 2019

Most people associate damaging water leakage with broken or leaky water supply lines. For good reason: water pressure in supply lines typically averages about 40 to 50 psi. Leaks from those pipes can flood a room or even the house if not properly dealt with immediately. But what about water leakage from clogged drain pipes? Can they be a source of indoor water damage, too?

The answer is yes. While the damage from a clogged drain pipe is usually more chronic and less acute than the critical event of a supply line rupture, drain pipes are a common origin for water that slowly damages the structure of the house, as well as supporting mold growth. Typical areas where clogs can trigger leakage include pipes connected to sinks, bathtubs, showers, and garbage disposals.

Here are some reasons why clogged drains may result in water damage:

  • Unlike water supply lines that are strong and tightly sealed to withstand continuous internal water pressure, drain pipes and joints are made to convey water flowing under much less pressure.
  • As clogs occur, water backs up inside the drain pipe. The continuous presence of standing water in the pipe may eventually cause leakage through the caulking and seals at threaded pipe joints.
  • Clogging means standing water may be contained within drain pipes for extended periods. This increases the likelihood of internal corrosion or other deterioration of the pipe material and joints. Moreover, when drain pipe clogs occur, homeowners often resort to caustic drain cleaners to clear the clog. These harsh corrosives degrade drain pipe material, often leading to leakage.  
  • Drain pipes are frequently routed through areas of the structure that aren’t typically visible to residents. Therefore, leakage from drain pipes may recur over a lengthy time span before it is discovered. In that time, considerable damage can occur to surrounding structure and mold growth may also be present.