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Kitchen Sink Plumbing Rough-In Dimensions? (Explained)

The kitchen sink has a plumbing rough-in dimension. This is designed by the designer when the house is built. It can also be collected from the kitchen sink manufacturer guide as well.

You may ask if there are any general kitchen sink plumbing rough-in dimensions for all kitchen sinks. Let us help you find the information you are looking for and provide you with some essential information regarding this.

What Is The Kitchen Sink Plumbing Rough-In Dimensions?

The kitchen sink plumbing rough-in dimensions for the drain discharge hole is 16 – 20 inches above the floor. This height varies based on the sink manufacturer manual or the kitchen designer. The P-Trap must be a minimum of 24 inches beneath the kitchen sink and the rough-in is dependent on it.

Kitchen sink plumbing rough-in dimensions are crucial and important for any house design. These dimensions help keep space under the sink and provide the necessary space to perform repairs, plumbing, and cleaning.

Rough-in is basically the part of the construction where water and plumbing wires are brought-in when performing it for kitchen sinks. 

During this part of the construction, the lines for the kitchen sink are set according to the design and layout of the designer or the manufacturer.

But the connection to the kitchen sink is performed after all the other construction is done. This rough-in helps set the water and plumbing lines appropriately so the kitchen sink works as intended.

There are multiple aspects that are required to be measured while working for the rough-in of kitchen sink plumbing. If you want to know the details of the kitchen sink plumbing rough-in dimensions, here are the generalized information regarding them: 

Supply lines to the sink:

Two holes are required for the supply line. The height of the supply line will be 2 – 4 inches above the drainpipe and horizontally the hot and cold-water lines need to be 4 inches apart from the centerline of the sink.

Drain line of the sink:

This is known as the discharge hole of the sink. This line must be connected vertically at the center of the sink, which will be 16 – 20 inches above the floor. Any mistake in this matter will cause the drainpipe not to work.

Fixtures of the sink:

The recommended sizes of the size-to-size buffer will be 20 inches from the center line. The minimum distance to the closest obstruction at the front buffer needs to be 30 inches.

Placement of the sink:

The sink must be placed 31 inches above the floor. This measurement is from the rim to the floor beneath the sink.

What is the rough in for a kitchen sink drain?

Rough-in is basically the part of the construction where water and plumbing wires are brought-in when performing it for kitchen sinks

The rough in for kitchen sink drain is 18 – 20 inches from the floor. The kitchen sink drain basically takes the wastewater of the kitchen sink to the drain line of the house. The rough in dimensions for a kitchen sink drain is essential and has to be set appropriately.

It said that a standard kitchen sink drain would eventually be 24 – 30 inches above the floor. This means that the rough in for the kitchen sink drain has to be around 18 – 20 inches from the floor. This dimension will help keep some space underneath the kitchen sink to provide access to necessary repairs and maintenance.

The space that will be found after the rough in of a kitchen sink drain will be used in setting the P-trap and fitting the hot and cold water lines. Although the rough in dimensions will vary based on the height of the counter and the depth of the kitchen sink that you will use.

What size pipe for kitchen sink rough in?

The pipe size for the kitchen sink rough in is 2 – 3.5 inches. The pipe that will be used for the kitchen sink rough in will be PVC in general. This pipe is commonly available in the market and is used by contractors across the globe for its reliability.

While determining the pipe size for kitchen sink rough in, you have to keep in mind the hole of the kitchen sink connections will be smaller than the diameter of the pipes that will be used. 

The diameter of the drain hole of the kitchen sink is considered to be 1.5 inches. But the pipe that will be used needs to be 2 – 3.5 inches in diameter to adapt to the drain hole.

What is the proper rough in height for a kitchen sink drain?

The proper rough in height for a kitchen sink drain is 18 – 20 inches from the floor. Every kitchen sink has a particular height for rough-in of the kitchen sink drain. This height varies based on the size of the kitchen sink and the height of the kitchen top that it will be set on.

It is expected that the height from the kitchen sink to the tabletop will be on average 24 – 32 inches. For this height, the rough-in height for a kitchen sink drain is around 18 – 20 inches from the floor. 

This dimension may vary based on the design of the kitchen or the requirement of the kitchen sink manufacturer.

How to measure rough in kitchen sink?

Measuring the rough in of a kitchen sink is crucial. The measurements have to be taken appropriately and noted down carefully. If you want to measure rough in of a kitchen sink, you can follow the steps provided by us:

Clean the area beneath the kitchen sink:

Although cleaning the sink is not a part of the measurement of the sink, This will help you get the appropriate measures of the lines that will be set in the rough in of the kitchen sink. 

Clear all unnecessary items beneath the kitchen sink so that you can access the bottom of the kitchen sink properly.

Measure kitchen sink length, width and height:

First, you will have to measure the length, width and height of the kitchen sink. Measure the depth of the kitchen sink as well. While measuring the width of the kitchen sink, measure both the inside and outside of the kitchen sink. 

Measure the countertop height as well.

Measure height of the location of P-Trap :

The P-trap has a fixed height of minimum 24 inches beneath the sink. While measuring the sink drain, you have to measure the height accordingly so that the P-Trap can connect with the sink drain line properly.

Calculate the sink drain size:

While calculating the drain size height for your sink, keep in mind that you will have to keep adequate space for the supply lines to be connected and the P-Trap to be connected. Also, do not measure the sink drain height too low or it will cause issues.

Subtract the measurements of P trap from the total and also subtract the height of the countertop to get the measurement of rough in the kitchen sink.  

How to rough in kitchen sink plumbing? – How do you install rough plumbing in a kitchen sink?

There are many ways to install rough plumbing in a kitchen sink. If you want to know the simple ways to perform this, you may consider following our simple steps:

Check the height of the sink drain outlet:

Checking the measurements before attaching the pipes is a good practice. First, the height of the P-Trap before measuring anything. Ensure that the height of the P-Trap is at a minimum of 24 inches beneath the sink. The height of the P-Trap is important. 

Based on this height, you may have to change the height of the sink drain outlet.

Also, keep in mind to keep space above the sink drain outlet. This is also critical to remember when installing rough plumbing in a kitchen sink. 

Install the garbage disposal and other necessary elements:

After performing the necessary cross check of measurements, install the garbage disposal and any other under-sink component on the desired side beneath the kitchen sink. Connect it with the drain accordingly.

Set the drain tailpiece and waste pipe:

After setting the under-sink components, put the drain tailpiece underneath the kitchen sink drain and the continuous waste pipe under the tailpiece. 

The tailpiece helps to prevent anything big from entering the drainpipe and the waste pipe is essential to connect with the drain line.

Set the drain trap:

The drain trap is a U-shaped trap bend and J-shaped trap arm. This trap extends to the tailpiece of the sink and connects to the drain outlet on the wall. Connect all the under-sink components with the drain trap and connect them tightly.

Check for any leaks:

After doing everything, run water in the sink. Check for any leaks in the rough plumbing that you have just done.

Final Thoughts

The average dimension of the kitchen sink plumbing rough-in is 16 – 20 inches above the floor. This dimension varies based on the countertop height when the kitchen sink will be set, the height of the P-Trap beneath the sink and the dimensions of the sink manufacturer or kitchen designer.