Can You Use 1 1/2 Pipe For Shower Drain? (Explained)

Can You Use 1 12 Pipe For Shower Drain

A blocked shower drain or slow flow of wastewater through the drain is not what we expect. To let the shower drain work effectively, the size of the shower drainpipe is crucial. While an oversized drain pipe can kill the normal flow of wastewater, an undersized pipe would flood the shower base.

The first question that pops up in mind is what size of the shower drainpipe is suitable. Though the standard size of the shower drainpipe is 2 inches, a few people also use a pipe of 1 ½ inch. Using a 1 ½ inch drain pipe is rare as people are still unsure about its effectiveness.

To clarify the matter, we are here with the article to tell you whether showers can have a one and half inch drain or not. If yes, you will get to know how you can do so.

A 1 ½ pipe can be used for shower drain in some areas. It is effective for draining water in small bathtub areas but may overflow the shower base if the water flow is high. Though a 1 ½ pipe is not as efficient as a 2 inches shower drain pipe, it would suffice in small areas.

Let’s delve into the matter more to figure out whether and how you can use a 1 ½ pipe for the shower drain.

2 Simple Steps To Use A 1 ½ Inch Pipe For Shower Drain:

To make things simple and understandable, let me divide the activity into two parts. In the first part, the discussion will be on how you can install the shower drain. In the later part, we will talk about how to install a 1 ½-inch pipe for the shower drain.

Let’s start the installation:

Part-1: Installing Shower Drain

In this part, we will learn the basic steps of installing a shower drain. Installing a shower drain is not so difficult if you know the right process. If you install the shower drain effectively, setting the pipe becomes easier and simpler.

Here are the simple steps to installing a shower drain:

  • To start with, apply either silicone caulk or plumber’s putty throughout the rim of the shower base area with a spatula. Then press it strongly so that they settle well.
  • Now, push the rubber and slip the washer from the bottom of the shower base. Simultaneously, adjust the drain nut on the drain body.
  • Carefully tighten and fix the shower drain on the base and clean up the extra putty or silicon, whichever you have used.
  • Next, you have to place the shower base just in the middle. This would make the drain body at the center so that it can connect to the drainpipe easily. Positioning the shower base at the center, therefore, is important.

With that, you are done with installing the shower drain. Just let the putty or silicone dry out before you start with the next part.

Part-2: Installing The 1.5 Inch Pipe

Now is the turn to install the 1.5-inch pipe. Let’s go straight to the point of setting the 1 ½ inch pipe for the shower drain.

Here are the simple steps to install a 1 ½ inch pipe:

  • First, you have to insert the compression gasket through the drain body. Do it from the top so that it reaches the top of the drainpipe.
  • Next, you have to fix the compression nut on top of it. Place and tighten the nut. To tighten the nut, you are supposed to get a tool with the drain package.
  • Now place the metal strainer on the drain body in a way so that it stays below the shower base.
  • In the last part, you can use putty or silicone and let it dry.

Expert Tip To Install 1 ½ inch Pipe For Shower Drain:

To install a 1 ½ inch pipe, you need to place it correctly. You have to place it exactly at the center of the flooring. Then the pipe should go around ⅛ inch down from the floor.

Make the measurements correct. If necessary, mark the pipe so that you can insert the right portion of the pipe into the drain. If necessary, cut the pipe short.

Can Showers Have A And Half-Inch Drain?

Showers have a level threshold to flood. Also, showers with multiple openings spread water randomly from different angles. In that case, using a small pipe may not help you to effectively drain out water or overflow. This is why the size of the shower drainpipe is crucial.

Ideally, the shower drain pipe should be 2 inches. It is the standard size that lets water flow easily as the size is large enough. Even if the shower tray is small, a 2-inch pipe can effectively drain out water.

Another reason why 2 inches drain pipes are commonly used is that they are approved by most of the building codes. However, the building code may differ from state to state. But in general, 2-inch pipes are accepted in most buildings. Nevertheless, some may require larger or smaller shower drain pipes depending on where it is being used.

Now if you ask about using a 1 ½ inch shower drainpipe, the straight answer is you can use it in certain areas and cases. Mostly, 1 ½ inch shower drain pipes are used in small bathtubs where water flow is minimal and the volume lets you store some water. But still, using a 2-inch pipe won’t harm you. In fact, it would make things faster.

The point is, you can use a 1 ½ inch shower drain pipe. But the efficiency is not as much as the 2-inch pipe. Honestly speaking, a 2-inch shower drain is slightly better than the 1 1 2 inches for draining water effectively. But at the same time, some building codes don’t allow you to fix a 2-inch pipe but approve to use 1 ½ inch pipe.

Does A Shower Drain Need a Vent Pipe?

To clean out the shower water, a vent pipe is required. A vent pipe lets water move to the sewerage pipe or septic tank. Without the vent pipe, releasing the shower water is not effective or fast. With the vent pipe, the shower becomes empty and the water flows without any restrictions.

What Is The Ideal Pipe Size For a Shower Drain?

For the general shower drain, the standard and ideal pipe sizes are 2 inches. The 2-inch pipe is large enough to let all the wastewater go away. While a smaller size would restrict the water flow and an oversized one would make the process slow. Thus a 2-inch pipe is adequate for the shower drain.

Hence, don’t cut your 2-inch shower drain to 1 1 2 inches by listening to anyone.

What Pipe Size Is Good For Bathtub Shower Drain?

Bathtubs can reserve the water for some time. Not only that. Most buildings allow bathtub shower drains to have a 1 ½ inch shower drain pipe. As there is no harm in letting the water drain out slowly, it is enough to have a 1 ½ inch shower drain pipe for bathtubs. So 1.5 inches of pipe for the bathtub drain would suffice.

What Size Of PVC Pipe Is Used In Shower Drain?

If you consider PVC pipe for shower drain, ideally it should be 2 inches. It is the standard size that is reliable for the shower drain. A 2-inch PVC pipe would suffice when it comes to draining out a flow of water. It effectively drains out water and keeps the bathroom clean.

How Many GPM Can A 1 ½ Inch Drain Pipe Handle?

GPM denotes the gallon of water the drain pipe can drain out per minute. Now when you are getting a drainpipe, knowing the GPM would help you understand the efficiency of the pipe.

Generally, a 1 ½ inch pipe in a ¼ inch per feet area has 4.9 GPM in half-full flow. If it is a PVC pipe, the rate in half-full flow would be around 8.3 GPM.

Therefore, the GPM fluctuates between 4.9 to 8.3 GPM depending on the pipe material.


So, can you use a 1 1/2 pipe for the shower drain? You can use a 1 ½ inch shower drain pipe. But you have to consider some other conditions like the building code and its effectiveness.

Anyway, though you can use a 1 ½ inch shower drainpipe, you should first consider its compatibility.

3 thoughts on “Can You Use 1 1/2 Pipe For Shower Drain? (Explained)”

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