Improper Application of Plumbing Materials and Why It’s a Problem

One of my home inspectors here at Sky Blue Inspections recently discovered improper plumbing materials installed under a home’s sink during an inspection. This is another case of DIY gone wrong, highlighting potential future problems.

A sink with pipes and hoses

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The white corrugated flexible pipes in your photo are not an appropriate substitute for a P-trap. Although they bend into a “U” shape, they don’t work the same way a real P-trap does.

Here’s why:

A P-trap must hold a water seal

A proper trap, such as a standard PVC or ABS P-trap, is designed to hold a small amount of water permanently. That water creates a seal that prevents sewer gases from entering the house.

Corrugated tubing traps debris

The ridges inside those hoses create many places where grease, food particles, and soap residue can collect. This causes frequent clogs and slow drainage. Smooth trap pipes are designed to prevent buildup.

It doesn’t meet plumbing code

Most plumbing codes (like IPC and UPC) require a properly sized, smooth-wall P-trap, correct trap arm length, and rigid connections.

Flexible accordion-style drain tubing like this is usually not approved for permanent installations.

They can sag and form multiple traps.

While this setup keeps water in place, it can become completely full. This configuration may stretch, shift, and sag over time. Flexible hoses tend to droop, which can accidentally create multiple low spots (double traps). This can lead to slow drainage, air locks, and gurgling when draining the sink.

Summary

These hoses are usually meant for temporary or emergency use only, not for long-term plumbing. The proper solution is to replace this type of problem with solid, smooth-bore piping.

At Sky Blue Inspections, we are trained to look for these issues when inspecting a home. We document the problems and recommend having them resolved by a qualified professional.

Visit our website for more information or to schedule your home inspection in Burnsville, MN, and the southern metro areas, from Chaska to Hastings. You can also contact us today at 652-675-8895, by email, or use our online “Schedule Now” feature to set up an appointment.