Flexible Drain Lines

flexible drain line

I often see flexible drain lines installed under sinks in kitchens and bathrooms that have been remodeled.  They are also called accordion or corrugated drain lines.  Go into just about any store selling plumbing supplies and you will see them.

Why would you use a flexible drain line?  Their flexibility allows them to be adjusted to different angles and alignments.  They can be easily bent or shaped to accommodate situations where pipes don’t line up.  Simply put, they are easy to install. 

Of all the projects I have completed in my home, plumbing jobs consistently rate as my least favorite.  Most of the time, it takes several trips to the hardware store before I get all the right connections and pipes.  I have been tempted to install a flexible drain line to just be done with the job.  But I haven’t used one.

Why shouldn’t you use a flexible drain line?  Plumbing standards require that drain lines should be smooth on the inside and be capable of self cleaning.  Self cleaning is the swirling action of the water going down the pipe.  Flexible drain lines have ridges that prevent the swirling action.  The ridges will also trap debris making them more prone to clogging.  And they tend to get rather nasty on the inside.

​When I see a flexible drain line, it usually is a tip off to me that a qualified plumber did not do the plumbing installation and I always recommend it is replaced.