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View Full Version : How far should a p trap be from the drain?


david_plumer
Feb 5, 2011, 01:01 PM
I have a kitchen sink and the p trap is in the crawl space about a 3 to 4 foot drop. When the water drains you can hear it some what gurggle. I was wanting to know if I move the p trap to about a foot away from the drain would the sound stop. Due to less fall?

oneexception
Feb 5, 2011, 01:28 PM
It might, but the gurgling may not be from the drop. I have seen situations when the water that is draining through a horizontal pipe gets slightly airlocked and sloshes back and forth as it drains, causing the gurgling, even when the plumbing is properly vented. Can also be caused by an airlock from lack of a vent. However, that might not be the case with your situation. Unfortunately, sometimes you just need to go by trial and error until you get the results you are looking for.

mygirlsdad77
Feb 5, 2011, 02:14 PM
2006 upc code; 1001.4.. The vertical distance between a fixture outlet and the trap weir shall be as short as practical, but in no case shall the tailpiece from any fixture exceed 24 inches in length.

Also, the trap must be properly vented.

massplumber2008
Feb 5, 2011, 04:37 PM
Hi Guys...

David, if the PTRAP is below the floor then there is a good chance that the vent connection is also below the floor so you will either need to move the PTRAP and connect into the existing vent ABOVE the floor, or you can move the trap up (be sure to remove trap under floor... no double traps) and install a mechanical vent, called an AAV (air admittance valve) above the floor. The AAV may not be code approved in your area so you will need to consider that, too.

Most likely you should just leave it all alone...

Let us know what you think about this, OK?

Mark

PlumbRob7
Feb 5, 2011, 10:25 PM
In Canada the fixture outlet pipe must not exceed 1200mm (4 feet). Also the length of the trap arm will affect the venting, the length cannot exceed the diameter of the drain... example: at 1/4" per foot of grade a 2" drain must not exceed 8' Or you will be s trapped which will restrict your venting. In other words too much grade on a trap arm will affect the venting.
An air admittance valve probably won't help you out always avoid them As they are called cheater vents for a reason