In some cases the drain from the wall and sink line up but when they don’t you will need to offset the drain. This is where the drain ends up being offset from the drain pipe. You will need to use extensions and fittings to help make the drain connection.
In this article we will be discussing step by step process of plumbing an off set drain.
What is an Offset P Trap?
An offset p trap is one where the drain on the wall and the sink do not line up. in such a case the drain is an offset drain and will need a 45 and 90 degree elbow to line it up.
One will have to use 45 fittings to divert the drain angle towards the drain on the wall.
How To Plumb An Offset P Trap
- Install Adapter on the Tail Piece
- Use a 1 1/4 by 1 1/2 trap adaptor , keep it in the middle of the tail piece so that you can raise or lower it to get the correct slope. The tail piece is the straight piece that extends down from the drain.
- Dry fit the p trap on the drain.
- Using a measuring tape measure the length of the pipe that will fit between the p trap and the trap adaptor. Then cut the piece you just measured.
- Glue the p trap and the trap adaptor together using the piece we just cut. Make sure to use the correct type of cement for the pipe you are using
- Put the assembled piece back on the tail piece and then snug it with your hand. this is because our drain coming from the wall and sink drain are offset from each other. We will need to use a 45 degree to divert the drain angle towards the sink drain.
- To do that dry fit the 45 drain on the drain pipe to make sure they align. if they don’t you will need toa djust the length of the drain pipe coming out of the wall. Length of the drain pipe will depend on how offset both drains are.
- If they align then glue the 45 back on the drain and check for slope. You will need 1/4 inch slope per foot on a 1 1/2 inch drain pipe.
- Again align the p trap with the 45 and measure the piece that will go between them.
- Unscrew the 90 from the p trap and glue the piece we just cut into the 90
- Now glue the 90 into the 45 and hand tighten everything together and check for slope, then tighten everything by hand. If drain is flat, loose the slip joint and raise it by 1/4 inch to have 1/4 inch slope on the pipe.
- Finally fill the sink with water then open the drain and watch for leaks as water passes and adjust accordingly.
FAQ on Offset P Traps