Can Showers Have A One and Half Inch Drain? (Explained)

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When it comes to plumbing, there are a lot of things we take for granted. So if you’re wondering whether or not your shower has the right sized drain, here are some things you should know.

Showers can have a one and half inch drain if the building codes in the given areas require them to be of that size. Still, you can decide to use the small-size drain if you don’t want to use a 2-inch drain. And if you only have a larger pipe you can reduce it to 1.5 inches by using a reducer.

Does a Shower Require a 2 Inch Drain?

A shower requires a 2inch drain pipe as it is the standard size and most building codes prefer it. Most of the shower pans are fitted with this size of drain pipe. Moreover, it is normally large enough and can prevent the shallow shower trays from overflowing.

You should also be aware that your locale’s code for the shower size and the one for the local buildings can be a little bit different. Some of the cities do need a one and half inch drain, though you may still need to opt for a 2-inch pipe. Furthermore, many of the standard pans and trays are outfitted for larger pipe sizes.

And hence you won’t have to go for another option. As for the contractors, they may try to find a way of using the small-sized pipes. However, this may not be enough to prevent the shower from getting flooded.

Flooding can at times cause serious problems with the floor and for this reason, you need to prevent such cases. Generally, showers do have a lower limit for flooding. And it’s due to bathtubs lacking high walls.

It is therefore vital to use the large-sized drains to keep water streaming in the pipes rather than on your floor.

Can a Shower Drain Be 1.5 Inches?

A shower drain can be 1.5 inches if a building code needs it to be that size. Moreover, you can choose to have it if you don’t want to have a two inches pipe. And this is the one the majority of shower trays are designed to put up with.

Though if you have the standard size and you need a small size the experts will advise you to just reduce the size of the pipe. And you will have to glue a reducer in it to create a smaller opening.

You also need to take note of the amount of water that is getting in your shower before opting for the 1.5 inches.

For instance, most of the showers are currently created with many heads and the water can spray from different angles. Therefore, there may be excess water for the small-sized drain pipe to hold. In case you have doubts about whether the shower will be fine with the 1.5-inch pipe, then reach out to a professional.

It’s great to have the opinion of an experienced plumber first rather than just installing a drain pipe that’s very small. And can result in problems in your washroom.

What Is the Minimum Size Pipe for a Shower Drain?

The minimum size for a shower drain is 1.5 inches. And you can use this size if it is the only one available for your shower, but the most standard one is two inches. Besides, a shower needs a proper drain so it won’t fully get covered by the water and end up overflowing.

This implies it will exceed the required limit. However, a drain always needs the help of air behind it during draining. For this reason, you need to think about a pop-up drain for your sink.

If it can not raise a sufficient amount, the sink may start filling up with water.

How to Prepare for Shower Drain Installation After Choosing the Size

After you’ve settled for the correct size of a shower drain you need to get ready for the installation as follows;

Have a plan

A plan is very important as it will enable you to realize where the pipes will pass through. You will also know where you can place the trap and the way you’ll vent it. You should begin by measuring and creating a sketch of the way you intend to position your drain.

This will help you remember everything as you go shopping for the pipes and the other things you will need.

Assess How You Can Access The Pipes

You need to know how you will reach the pipes.

In any case, the operations will take place in a first-floor washroom, consider having them run underneath the basement. And with this, you may need a ladder and also have to work overhead.

In case your home is constructed without a basement and on a cement slab then there may be a lot of work. Installing the shower drain on the first floor will entail cutting or breaking either one or many tubes in cement. In this case, you will need a plumber to help you out.

How to Install a Solvent-Glued Shower Drain

You can effortlessly install a solvent glued shower drain after you are done with the preparations. Check out the following easy-to-understand steps;

Fix the Drainpipe to a Reasonable Height

Ensure you check the instructions from the manufacturer to help you as you adjust the drainpipe. And for tons of drain fittings, it implies you cut the pipe to a precise point of a subfloor.

Have the Drain Assembly Ready

The majority of solvent glued shower assemblies do have different sections. For instance, the upper part extends downwards via the drain opening at the base of the shower. And a lower part with the female thread which screws on the upper section.

Dismantle and Set the Upper Section of the Drain Assembly

First, you need to dismantle every section of the assembly. Then set aside rubber sealing and cardboard friction washers. After that, you can insert the upper part of the assembly and then apply a drop of silicone caulk.

Do this on the areas next to the flange of the drain’s opening. Proceed to place the drain assembly’s upper part on the opening and then press it downward.

Fasten the Assembly

You can place a rubber sealing gasket under the shower base. And paper friction gasket on the male upper body threads. Thread the lower area on the upper region and fasten the assembly.

Do this until silicone appears around the pipe opening flange.

Rub off Remaining Traces of Silicone and Glue the Drainpipe

If you still see silicone on the pipe, you can wipe and then connect the metal grate to the drain assembly’s top. After that, solvent glue the pipe to drain assembly. Spread the plastic primer from beneath the shower base.

Do this around the external edge of the pipe and the internal area of the socket. That’s on the lower body of the drain. Spread a little solvent glue and then slip the drain onto the socket.

Hold this into position until the bond is perfect. Allow both the silicone and glue to cure for a day before you start using your shower.

Who Can Install This Type of Shower Drain?

This kind of shower drain is recommended if you can easily access the area under the shower. Especially from an incomplete crawl area. And if you cannot reach it then you may opt for a compression style.

Solvent glued drains are PVC plastics. And in case you have the plastic pipes, ensure you match your shower drain to a type that matches It. The obsolete ones can use ABS plastics.


You can certainly have a 1.5-inch drain pipe, though many professional plumbers recommend a 2-inch drain pipe for a shower. Ensure you examine the amount of water flow the shower will have, plus the way the shower tub is designed. This will enable you to understand what’s perfect for your home.