Sink Drain Through Floor

Rough in sink drain through floor.

Sink drain through floor.

The holes must follow a straight line across the floor and must ascend or descend so the pipe will be sloped 1 4 inch per foot. Running drainpipe through joists calls for meticulous work. When you are installing a kitchen sink drain pipe along with the drain attachment on the floor you will need to be able to fit the drain and the parts together. If joists are 16 inches on center and pipes run across them at a right angle holes should differ in height by about 3 8 inch.

I just went through the same exercise myself including the installation of a pedestal sink. Drains that are in the floor are quite common. Sink drains that exit through the wall behind the sink require a p trap and sink drains that exit through the floor beneath the sink require an s trap. Without a route to the main sewer system or septic field wastewater may have nowhere to go but to back up into your fixtures or up through floor drains.

Distance from the floor or wall to where the drain enters the wall or floor distance between the floor and the water supply pipes. In order to do this you will have to attach the drain to the s trap below your sink where it falls into the floor including applying putty and putting drains into the base of the sink adding the tailpiece and then fitting the t. Distance right to left from each water supply pipe to the drain. If the potential sink location is on a 2nd floor i can t imgine not having to bust into the ceiling under it too even to run the drain straight down.

The commode drainpipe is the largest in diameter either 3 or 4 inches and. That drain tailpiece runs from the sink to the drain. The sink s drainpipe runs downward to connect in the floor to the main drainpipe which originates with the commode. If you don t have a vent on your sink drain you can use one of these air admittance in line vents from oatey here.

If your sink drain is located in the floor all that you need to do is reposition the p trap slightly. Sit on the floor with the sketch in hand and visualize how the back of the pedestal sink will match up with the supply lines.