How to Install a kitchen Sink Drain

Before you can install a Kitchen Sink Drain, you should know what a kitchen sink drain looks like. Although I have used ABS (acrylonitrile butadiene styrene) pipes and fittings in this example, the same fittings are available in PVC (chlorinated poly-vinyl chloride). The main difference is that ABS is better in cold weather, but PVC is better for outdoors and warmer climate applications, PVC will generally last longer than ABS. But, many plumbers prefer ABS because it is easier to work with when it comes to gluing it, ABS does not require a primer and the glue set much faster so there are fewer chances of error.  Here are a few typical examples:


PVC Sink Drain
Double Sink Drain Fig. 1

 

In this photo you see a typical PVC dual kitchen sink  drain, that drains through the floor.

 

 


Double Kitchen Sink Drain
Double Kitchen Sink Wall Drain Fig. 2

 

In this photo you see a typical double PVC  kitchen sink  drain with a Dishwasher drain inlet, that drains through the wall.


Next I would like to show you the parts you are going to need for an ABS (black plastic pipe) or PVC (white plastic pipe) drain pipe assembly. To start with, you are going to need two strainers for a double sink installation, only one if you are installing a single sink.  You can see more about how to install a kitchen sink drain in this video.

Stainless Kitchen Sink Strainer
Typical Stainless Steel Kitchen Sink Strainer Fig. 3

Kitchen Strainers come in either metal or plastic, the metal ones usually are made of stainless steel, but some have galvanized steel or brass parts as well.   You can get them in chrome, brush nickel, brass, oil rubbed bronze and stainless steel.

The size is a standard (3-1/2") and fit nearly all kitchen sinks,  some laundry tubs as well as some bar sinks.

Typically, they cost between $10.00 to over $100.00 depending on the quality and the finish. You can purchase them at your local home improvement store.  If the ones you would like are not available you can order them here.


Shower Door Seals 2


 

Next, you will need the following ABS, PVC or brass fittings

 

Plumbing Brass Tailpiece
Brass Tailpiece Fig. 4

 

 

This is a "Tail Piece" is used to link the drain assembly (strainer) to the drain pipe which is normally 1 1/2" in diameter, for kitchen drains.  The "tailpiece" attaches to the "sink strainer" and slips into the "trap adapter." (see photo - ABS trap adapter, Fig. 5) The "trap adapter"  is normally glued on to the drain pipe. Typical tail pieces come in brass, plastic or chrome and cost just a few dollars. They're also available in 2", 4", 6" & 8" length. Don't worry, they don't cost much. 


Trap Adapter
ABS Trap Adapter Fig. 5

 

This is a typical female "trap adapter" fitting; it is glued onto the drain pipe using ABS or PVC cement depending on which type of pipe you are using and it is used to attach the tailpiece to the drain pipe, this makes a removable water tight connection, in case you ever need to take it apart in the future.

This fitting  is made of either ABS or PVC and comes in various sizes include 1 1/4" all the way up to 2" for typical household plumbing.  This fitting also comes in a male version and can be used where space is at a premium.


 

Abs P Trap
ABS "P" Trap Fig. 6

The next fitting you will need is what is commonly referred to  as "P" trap (because it looks like the letter P). The "P" trap is meant to hold a small amount of water that acts as a barrier to prevent sewer gas and odors from entering your home through the drain pipes.  For this reason "P" traps must be correctly installed and used in all drain applications that are connected directly to your home's sewer pipes.  A "P" trap is generally used to connect the sink drain to a wall sewer pipe inlet.


White PVC drain Trap
PVC "S" Drain Trap Fig. 7

 

Warning - "S" Traps Are No Longer Approved for Residential Plumbing

If you have a sewer pipe inlet that is coming straight up from the floor below the sink, then you will need to use an "S" trap as pictured here.  "S" traps do the same job as "P" traps so you should use one or the other, not both. This trap comes in both PVC and ABS.

 

The code now requires you to use a "P" trap even for through the floor drain.  The following diagram will illustrate exactly what I mean.  Notice how the "P" trap is first connected to a short length of straight  pipe before it is hooked up to the vertical drain pipe. This is done in order to break the siphoning action that is normally created by a straight "S" trap connection.

Red Arrow Trap
P trap drain for a through the floor drain installation. Notice the short piece of straight pipe that prevents this from being an "S" trap.

 

 

This type of drain connection also allows for the installation of an "AAV" (air admittance valve) should venting be required.

 

 

 

 

Air admittance valve for P-trap
This photo shows the installation of an AAV valve.

There are many alternatives when it comes to installing a "P"  trap, these may vary in accordance with your local building codes.  I recommend you check with your local building inspector to find out what is considered acceptable in your area.

Plumbing Vents:  Code, Definitions and Specifications

See my Plumbing Vents, article of April 30,2015; on plumbing vent codes, definition and specifications for more on how to install a Kitchen Sink Drain.

 

 

 


ABS Plumbing Coupler
ABS Coupler Fig. 8

 

This is a 1 1/2" ABS  coupling. A coupler is used to join two pipes together.  There are many types of couplers available, some are reducing couplers (used to join two pipes of different diameter together),  some are threaded coupling, some are "union" type coupling (the one's that can be taken apart) some are made of ABS, some are PVC and still some are made of metal  or rubber.  You would use a couple like this one to join you sink drain pipe to your sewer drain pipe.


Kitchen Sink Drain assembly
Kitchen Sink Drain Assembly

In order to better understand just how all of this fits together, have a look at the above diagram. It contains nearly everything we covered in this article about "How to Install a Kitchen Sink Drain."  Note that the diagram shows a dishwasher "waste nib" this is  sometimes referred to as a dishwasher "barb" connector. Since, I have not mentioned this type of connector  in this article, I plan to cover it, in more detail in a future "How to Install a Dishwasher" post. The diagram is for a typical single kitchen or laundry tub installation. You will need to modify it a bit if you are installing a dual kitchen sink.


Kitchen Drain Installation Instructions

Follow these directions for a typical out of the  wall drain assembly.

You should dry fit everything before proceeding with gluing all your parts, just to make sure that  everything will fit perfectly.

Step 1:  Install the strainer(s) Fig. 3,  into the bottom of your sink.  Keep in mind that the cardboard washer goes on last, just before  the nut, it primary functions is to act  as a lubricant for the large nut, it keeps the rubber from twisting as the nut is being tightened.

Step 2:  Attach the "Tailpiece" Fig. 4,  to the bottom of the sink strainer making sure to properly install the "Tailpiece Washer" (see Fig 3).

Step 3:  Slip the "Trap Adapter" Fig.5, onto the "Tailpiece", Fig. 4, and tighten slightly.

Step 4:  Slip the "Coupler" Fig. 8, onto the sewer drain pipe coming from the wall, remember not to glue anything yet.

Step 5:  Now line up the top (short side, inlet) Fig. 10, of your  "P Trap" with the base of the "Trap Adapter"  and line up the Outlet end (short 90° end) with the "Coupler" on the sewer drain pipe.

Photo of P-Trap
P-Trap Fig. 10

Step 6:  Measure the distance from the bottom of the "Tailpiece" to the top of the "P Trap" (the inlet side) and  add approximately  3".  This will give you plenty of length for adjustments.

Step 7:  Cut a length of 1 1/2" pipe Fig. 12, to fit between the "Trap adapter" and the "P Trap" as per your measurements.

Step 8:  Insert one end of  the pipe into the "P Trap" and the other end into the  "Trap Adapter" Fig. 10a. Remember, No Glue!

imagesCA13WEJE
Installing a P-Trap Fig. 10a

Step 9:  Slide the "P Trap" up the "Tailpiece" until the "outlet" end of the "P Trap" lines up evenly with the wall drain pipe and "Coupler".

Step 10:  Measure the distance between the "P Trap" and the "Coupler" then add 1".

Step 11:  Cut a length of pipe to be inserted into the "P Trap" and the "Coupler" as per your measurement in step 10.

Step 12: Insert the pipe into the "Coupler and the "P Trap" check for alignment. Make sure everything fits well and everything looks good. If you are happy with everything so far go on to step 13.

Step 13:  Starting at the wall drain pipe glue the "Coupler" onto the drain pipe.

Tip:  When gluing plumbing pipes, be sure that the surface is cleaned properly and that you apply the proper glue to both pieces of the fittings to be joined.

 

Step 14:  Now glue the horizontal pipe to the "Coupler" and the "P Trap" outlet.

Step 15:  Now check the length of the pipe going from the top (inlet) of the "P Trap" to the "Trap Adapter" if it's too long you will need to cut a piece off, if it looks O.K., you can leave it.

Step 16:  If you have decided that everything looks fine so far, you may apply glue the final parts in place. Glue the last remaining piece of pipe going vertically from the top of the "P Trap" to the bottom of the "Trap Adapter".

Let the glue stand for approximately 30 minutes and you will be ready to use your new plumbing.

Congratulations, you are done!


Additional Information

Diagram of dual kitchen sink drain installation
Dual Kitchen Sink Installation Fig. 11

This is a diagram showing a typical dual sink installation, note that the plumbing code (regulations) sometimes differs from region to region. You will have to familiarize yourself with your local plumbing codes in order to carry out the proper type of installation.


abs plumbing drain pipe
Fig: 12, Abs Plumbing Drain Pipe

This is a typical 1 1/2'' piece of ABS pipe. You can use PVC if you local codes call for it.  You will need this to join your fittings together and attached it to the main drain.

 

 


ABS Cement
Fig 12, ABS Cement

 

ABS cement is used to glue the joints together if you are using  ABS  tubing and fittings. If your pipe is PVC then you will need to use PVC cement and PVC cement solvent, follow the manufacturer's directions  when applying.

 


Tip: Use the appropriate cement for your type of applications only


Note, to our readers, I have tried to make this article as clear as possible. Please feel free to add your comments and let me know if you had difficulty understanding any part of these instructions. If you have any suggestions for improvement I would greatly appreciate it if you could pass them along so that I can improve this article for our future readers.  Many thanks.


 


10 thoughts on “Kitchen Sink Drain”

  1. Im installing a hanging vanity. We have a copper waste drain, however Im wanting to do the plumbing in ABS. To connect me ABS pipe to the copper waste line would I use a threaded “trap adaptor” as shown on this page or one of those clamp style connectors?

  2. I have an old house with all drains in the floor instead of the wall. I need to fix the plumbing in my kitchen sink and was confounded because not only are s traps no longer kosher, but none of my plumbing is vented. I’m also going from a double to a single bowl.

    Seeing your picture of the kitchen sink with the T and the vent coming off the top is the perfect solution for me!

    I can now show this photo to the folks at Home Depot to get exactly what I need. Great page here!

  3. I know this is an old post, but I thought I would mention that S traps are no longer allowed according to modern codes. The S traps allow the water to be siphoned out of the trap and thus sewer gases can come up through the fixture.

    The fixture must be vented at or before the point at which the drain goes down through the floor. (Even the ones that go through the wall must go down through the floor to meet up with the main drain and they also must go up through a vent that goes either through the roof or around and terminates above the roof line)

    If you have a fixture that already has a drain through the floor under the sink, instead of having a part that just goes down in an S you replace it with a sanitary tee that still pushes the waste down but then you have a vent on top of it. In some cases you can put an Air Admittance Valve (AAV) on top, but this is banned in some states. So another option is to have a 1/8 bend on top of the sanitary tee and have a pipe that runs vertically at an angle through the wall and attaches to the main vent stack or branch vent. Remember that a vent pipe cannot run vertically until it has reached at least 6 inches above the flood level of the highest fixture it serves.

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