Kitchen Sink Plumbing Rough-in Height Dimensions Discussed

Kitchen Sink Plumbing Rough-in Height

The kitchen’s rough details are essential to accurately set up the plumbing and draining lines. For example, knowing the kitchen sink plumbing rough in height dimensions is essential if you want your kitchen to work perfectly with a cozy ambiance.

It showcases the height and distance of different parts of the sink plumbing. For example, it includes the height of the supply and draining line from the floor. Plus, rough details for the sink express the supply line’s position and its holes, sink placement, and fixtures.

All these dimensions are essential to keep your kitchen sink plumbing up and running appropriately. It also helps construct the lines and fixates in the proper distance so they don’t mingle. All dimensions are measured from the imaginary centerline for accurate measurement.

We will discuss the rough height and details in this plumbing guideline. So, let’s dive into it.

Terminologies for the Kitchen Sink Plumbing Rough In Details

Most homeowners may not be familiar with the term rough in detail for the plumbing system. Thus, it becomes more challenging for them to understand different words used to determine the plumbing setup in the kitchen.

So, what are the rough details for the sink and plumbing?

The rough-in detail refers to the distance of the different parts of the sink from an imaginary centerline. The reference point for the imaginary centerline is the drain line. Therefore, all the points for the kitchen sink fixtures, holes, and lines are calculated from it.

Here’s an example:

You need to place two pipes at an 8-inch distance. You have to measure the distance from their center, not the edges. Also, if a fixture needs to be at 5″ right, it will be 5″ right from the center of the sink drain pipe, not its edges.

A few crucial inclusions of the sink plumbing measurements for rough-in are:

  • Vertical supply line
  • Horizontal supply line
  • Drain or discharge hole distance from the back wall
  • Fixtures distance from the front buffer
  • Fixtures side by-side distances

There are many terms linked with the rough dimensions of the sink plumbing. We will discuss them in the next part.

Kitchen Sink Plumbing Rough-in Height Dimensions:

You must follow the kitchen sink plumbing rough measurements when setting up or renovating a kitchen. It helps you maintain the sink and plumbing without any malfunctions and inaccuracies in the installation process.

1. Height of the Supply Line:

The supply line height includes the measurement of two holes vertically. The holes will be 2 to 3 inches above the main drain line in your kitchen. Thus, you should measure their distance correctly before drilling the holes.

2. Supply Line Horizontal Measurements:

The horizontal supply line includes two holes. These are for hot and cold water supply lines, respectively. Once the centerline from the drain pipe is fixed, these two holes use the centerline as the guide. Therefore, the two holes will be 4-inches right and left from the centerline.

It means that the cold and hot water lines will be on either side of the horizontal supply line. Therefore, they will be at a 4-inch distance from the centerline. Since there’s no fixed rule on which side the cold or hot water supply line should be, you can interchange them. However, as a standard, most sinks in the kitchen will have the cold water on the right side and the hot water faucet on the left side.

Henceforth, the water supply lines for both types should follow the standard guideline. Or else the rough details will be inaccurate.

3. Vertical Discharge Hole:

Next, you need to measure the distance of the discharge holes. This measurement will be in a vertical position for accuracy. Finally, the vertical height of the discharge holes needs to be measured from the floor.

Usually, the two discharge holes need to be 16 to 20 inches above the base of the floor. As you measure, the vertical centerline for the measurement will be the center of the drain pipe. It will improve the accuracy of your measurement.

4. Side-by-side Distance of the Fixtures:

In the kitchen sink plumbing, you need to mount multiple fixtures. Thus, you must find the right distance for all fixtures from one side to another. Remember that the calculation of the side-by-side distance for the fixtures will be crucial to mount them without damaging the supply and drain line of the sink plumbing.

You must measure the distance from the centerline. The recommended distance is 20 inches from the centerline. If you have a tighter space, maintain at least 16 inches distance for the fixtures from the drain pipe centerline. If the distance exceeds that, both fixtures might fail to work correctly.

5. Fixtures Distance from the Buffer Point:

Next, you need to measure the kitchen sink plumbing rough in for the fixtures from their buffer point. Again, it is different from the side-by-side calculation.

For this, first, find the nearest obstruction from the fixtures. It can be the faucet, holes, or anything else. From the obstruction, the fixture should be at least 21 inches away. Plumbing experts recommend 33 inches distance for the fixtures from the nearest obstruction.

6. Sink Placement Details:

Finally, you have to count the rough details for the kitchen sink placement. For its calculation, you need to find the distance of the sink from the floor. Also, you have to measure the distance from the rim of the kitchen sink to the floor.

Ideally, it should be 31 inches from the base floor of your kitchen. This distance helps you prepare a kitchen sink cabinet for storage with ease.

What Is the Standard Height for a Kitchen Sink Drain

When installing the kitchen sink, you must count the drain height correctly. If you mount the sink drain at the wrong height, it will fail to remove the water from the sink. So, finding the right height for the sink drain becomes crucial.

Technically, the sink drain needs to be 28-inches above the kitchen floor. The height depends on the sink bowl depth and countertop height. However, plumbing experts suggest you maintain 24 to 30 inches of height for the sink drain from the base floor.

You must also ensure that the sink drain of the kitchen plumbing is accurate without crossing the water supply line. The scenario will be gross when it happens, as both water types will get mixed. It is not hygienic at all.

Kitchen Sink Drain Distance From the Wall

As part of your kitchen sink plumbing rough-in measurements, you should also find the proper distance of the sink from the back wall. Usually, the kitchen sink will be 8 inches deep. Therefore, its distance will be roughly 3 to 4 inches from the wall.

If the sink sits more distance from the wall, it will have difficulty finding proper stability. So, its water supply and draining will be affected. On top of it, the sink will be unstable, and you will find cleaning dishes challenging. So, bear in mind that its maximum distance from the back wall must be within 3 to 4 inches ad 24 to 28 inches above the floor.

How to Rough In Kitchen Sink Plumbing

When you measure the rough in details and height for the kitchen sink plumbing, you need to consider two factors.

  1. The drain pipe is the primary point
  2. The imaginary centerline as the guideline

With these two calculations in your hand, you can figure out the position of the different vertical and horizontal lines. You can also calculate the fixtures and hole distance for both hot and cold water supply lines, including the draining pipes.

For details, you may follow this YouTube video:

Frequently Asked Questions

How high should sink water lines be?

Answer: The water supply lines for your kitchen sink plumbing should be 20 to 22 inches above the kitchen floor. If you want more height, you can extend it to 24 inches.

How far can you run a drain without a vent?

Answer: You need to consider the pipe diameter for running a drain without the vent. For example, if the drain pipe is 1-1/2 inches in diameter, it can run for 42 inches without the vent. And for a 2-inch diameter, the running distance of the pipe without the vent is 60 inches.

How long is rough-in plumbing?

Answer: Plumbing professionals take 3 to 5 days to complete the rough plumbing setups in the kitchen and bathroom sink.

Does a kitchen sink need a vent?

Answer: Kitchen sinks without the vent will fail to get the correct water pressure for supply and draining. So, you mustn’t install the kitchen sink without proper venting.

What are the 3 stages of plumbing?

Answer: The three stages of plumbing include underground rough-in, above-ground rough-in, and finishing phases.


Kitchen sink plumbing rough in height is essential to measure the distance of the drain pipe, fixtures, and sink. With it, you can mount the sink appropriately. It is also crucial for maintaining the proper setup of the sink and its cabinet.

Hence, you should carefully calculate and finish off the underground and above-ground rough-in projects for the kitchen and bathroom sink. Or else the water supply of your home may malfunction.

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