How to Install a Floor Sink

How to Install a Floor Sink

Learning how to install a floor sink as a DIY project may seem like daring work, especially if you have little to no prior experience. However, this costly job can be done easily without hiring help by following some simple instructions.

Floor sink installation can prove to be quite costly, especially if you’re planning to hire an experienced specialist. This cost can be cut to one-fifth by doing it yourself.

The logistics of it, however, can faze many people. The details of how to take measurements, which grate and pipes to choose, and how to drain the sink properly is important.

So, this is a complete and easy step-by-step guide on installing a floor sink by yourself.

How to Install a Floor Sink

The floor sink usually has a deeper grate and a dome strainer to accommodate waste without splashback. Thus, the floor sink typical installation methods differ from the bathroom or shower drain installation.

It is important to know the proper measurement, angle, and the right materials for the floor sink. The following floor sink installation instructions can walk you through the process without any extra hassle.

Step 1: Measure and Mark the Floor

An average floor sink with five pounds capacity is usually 10’x8’ inches and five inches deep. It is important to take the proper measurement. Leave at least a five-eighths of an inch space on all four sides to accommodate any measurement error.

Each floor sink comes with detailed measurements mentioned on the packaging. It is best to consider those while removing the flooring. The subfloor should be cut to the exact same size as the drain. You should keep in mind the measurement of the sink lining when cutting the finished flooring.

Step 2: Remove the Flooring

Removing the flooring can become the hardest part of floor sink installation. It is best to install a floor sink before the final flooring is done. In case you are planning to install a floor sink on finished flooring, it is best to chisel out the tiles. If you are familiar with this work, a jackhammer can get the job done quicker.

Step 3: Create the Accurate Angle

The finished floor sinks have a slant in the base. However, it is important to angle your flooring around a sink in a way all the wastage automatically moves towards the sink. A quarter-inch slant should be created by planing the subflooring.

Since floor sinks are designed to drain heavier wastage, it is important to make sure the angle is just right. A steeper angle will drain the water without carrying the solids along with it, and the waste will settle on the floor. An angle too straight will cause stagnation.

Step 4: Use Heavy Duty or Epoxy Caulk

Floor sinks are designed to drain wastage in both solid and liquid forms. There is a risk of leaking. The average caulk can break or give in to the moisture.

Once the floor sink is installed on the floor, it is important to seal it with a heavy-duty caulk. Epoxy caulking can be a good solution, although slightly expensive, as it bonds very fast and is waterproof.

Step 5: Use a Waterproof Membrane

The floor sink drains out the liquid. So it is very important to use a waterproof membrane around the sink under the flooring. Even with a strongly sealed floor sink lining, the moisture can seep into the subfloor over time and create structural damage.

Step 6: Use Floor Sink Basket

The floor sink basket is an extension to the original floor sink that captures all the wastage. It can be made of various materials. The most common types of floor sink baskets in the market are stainless steel and plastic.

The floor sink is commonly made of stainless steel and PVC and is very durable. However, the sink and the pipe can wear out quicker with the weight of the wastage. A removable sink basket can capture all the wastage that can be late disposed of in the trash. This makes cleaning the floor sink easier as well.

Step 7: Double-Check Plumbing

If you are installing a floor sink by connecting to an existing plumbing, it is important to check whether the pipe is wide enough. It is recommended that you use the plumbing for the sewer systems such as a toilet plumbing unit to avoid blocking and overflowing.

For installing a new plumbing line altogether, double-check the required measurement of the pipe given on the box. The packaging of the floor sinks mentions the required plumbing width. You can even be extra careful and install plumbing with eleven-fifteenth of an inch more than the required diameter.

How to Drain a Floor Sink

Once the floor sink installation is complete, it is time to put it to use. You may find some trouble draining for the first time due to installation errors or other problems. A floor sink drain installation can solve the problem.

A floor sink drain, or a floor sink basket, is a removable attachment that captures the wastage. This allows easy removal of wastage without clogging the sink or the pipes. As a result, the floor sink drains without any trouble.

There are a few other factors that can help quick drainage without overflowing.

  • Cleaning the floor sink regularly keeps the grates of the floor sink and the basket free of any obstruction to water flow.
  • A cast iron floor sink is more susceptible to rust and malfunction. So, it is better to use a stainless steel or a PVC floor sink.
  • Using a floor sink basket can stop trash accumulation and allow easy drainage.
  • A plumbing vent creates an air pathway which creates a faster flow of waste through the plumbing lines.


Given the floor sink installation details, the work will hopefully become much easier. It is important to follow the correct instructions for a proper result. In case there is trouble with the measurement or installation, you can seek help from your floor sink supplier.

Floor sinks are usually premade in industries and thus, easier to install. The required size for each pound of wastage capacity can be found on the floor sink descriptions when buying. Besides, the plumbing and drainage system for a floor sink is quite easy to install as well.

With only a few tools, a hammer, and a caulk gun, you can install the floor sink following the instructions. Knowing how to install a floor sink is both a time-saving and cost-saving skill.

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