Messages and Online Forum Q&A

Re: Gurgling tub drain

From: info@builderswebsource.com
Category: Plumbing
Date: 16 Dec 1999
Time: 17:59:33
Remote Name: 205.188.197.153

Comments

Without seeing or hearing your situation first hand, I can only speculate. However, here is an excerp from my book, Building a Dream in the section on plumbing at:

http://www.buildingadream.com/book/plumbing.htm

"Another area where I've noticed a definite difference between plastic and cast iron is in shower drain traps. In our house, we happen to have one of each type, due to a particularly tight fit we had in one bathroom. There is no question that the shower with the plastic trap makes a loud, resonant gurgling sound as the water drains from the shower, whereas the one with cast iron is notably more quiet."

Although this passage refers to a shower, the same could apply to a tub. It's possible that your older tub has a cast iron drain. These are very quiet compared to plastic ABS drains.

Another possibility is that the vent stack is clogged from construction debris. This can cause the sound you describe. The only way to know for sure is to run a snake down the vent stack from the roof to be sure that there is no bird's nest or other obstruction blocking the air passage. If the vent is straight (no offsets), you might be able to see something obvious by shining a flashlight down the pipe. If you go on the roof, be very careful, particularly if it's wet or steeply pitched.

The other possibility is that the vent was not properly installed and is not providing adequate air passage. Without seeing the installation, this is only speculation since your addition should have been inspected and signed off after installation.

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