How to Build a Drain Trap for a Vanity

Although some bathroom sinks have a pedestal design, vanities are also a common sink option. Vanities offer the advantage of an underlying cabinet, which hides the plumbing pipes from view. Hooking up the plumbing for a vanity sink requires the installation of a sink trap to catch dropped items and to block sewer gas. Building the trap is only a matter of attaching a multiple curved section of PVC pipe together. Once assembled, the entire trap connects to the sink and to the main water waste line.

1 1/2-inch female PVC adaptor coupler
Two 45 degree PVC elbows
PVC cement
Reducing coupling

Instructions

- 1
  Pick up a 1 1/2-inch female PVC adaptor coupler and secure it onto the bottom of the sink drain by turning it clockwise until tight.
- 2
  Place two 45-degree PVC elbow sections directly next to each other so that they form an s-shape. Open a can of PVC cement and apply a 1/4-inch thick layer around the outside of the small end of one and inside the large end of the other. Slide the two PVC pieces together.
- 3
  Apply more PVC cement to the outside perimeter of a reducing coupling and insert the smaller end of the coupler into the floor or wall drain.
- 4
  Apply more PVC cement around the inside of the larger end of the trap assembly and push it into the wall pipe, holding it for 20 seconds.
- 5
  Slide the other end of the trap assembly into the pipe that emerges from the bottom of the sink. Screw the adaptor coupler clockwise to tighten it against the fitting. Alternatively, you can also glue this end in place with additional PVC cement.
- 6
  Locate the water shut-off valve next to the pipes on the rear wall. Turn the valve to return the water flow to the sink. Turn the faucet on at the sink and watch the trap carefully to ensure no leaks occur.

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