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Can I Run 3/4 PEX To Shower? How-To Guide

If you’re installing a shower in your home, do you know what size PEX tubing you need? You may wonder, “can I run 3/4 PEX to shower” and how much GPM it will provide. We’ll look at the advantages and disadvantages of using 3/4 inch PEX for your shower needs and some tips for installing it. 

Cross-Linked Polyethylene (PEX) Piping

Cross-linked polyethylene (PEX) is rapidly replacing galvanized steel and copper for water supply lines in new construction projects and remodeling jobs.

Can I Run 3/4 PEX To Shower

Early problems with PEX have been fixed over the years, and it has become a reliable material for water supply lines. PEX is just as durable as copper or steel, but it can be installed quickly, easily, and without tools. In addition, PEX tubing doesn’t require soldering or crimping as copper pipes do.

It’s become increasingly popular due to its ease of installation, cost savings, and durability compared with traditional piping materials such as copper and steel.

More than 60 percent of new construction residential water supply systems use PEX.

PEX Pipe Fittings and Sizing

PEX is a type of flexible plastic pipe that is used in plumbing. It’s made from cross-linked polyethylene and can be used in many applications. PEX is easy to install and resistant to corrosion, making it ideal for indoor use.

When choosing PEX, it is important to consider the “nominal” size of the tubing. This number indicates that a piece of pipe with such a designation will fit into fittings compatible with its dimensions.

Flexible tubing comes in various lengths, from 50 feet up to 1,000 feet. Residential plumbing systems typically contain PEX tubing ranging from 3/8 to 1 inch in diameter.

To ensure proper water pressure, installing ½-inch or ¾-inch PEX as your main supply lines is best. When replacing old supply lines with new PEX tubing, the standard practice is to use tubes of the same dimensions.

PEX Pipe Size Categories

PEX pipes are categorized into three groups based on diameter, including 1/2-inch PEX tubing, ¾-inch PEX tubing, and 1-inch PEX tubing. Each category has a distinct purpose and is used for different applications. The following sections explain these categories in more detail.

1/8 inch PEX Pipe

PEX pipes with a diameter of 1/8-inch are recommended for plumbing systems that supply water to an appliance like a refrigerator.

PEX Pipe Size Categories

1/2 inch PEX Pipe

PEX pipes with a ½-inch diameter are suited for supplying water to bathroom fixtures, including sinks, toilets, and kitchen dishwashers.

3/4 inch PEX Pipe

PEX pipes with a diameter of 3/4 inch should be used to supply hot and cold water to showers, washing machines, dishwashers, and other fixtures requiring more pressure or volume.

What Size PEX for Showers Do You need?

When replacing old water supply lines, it is best practice to use PEX pipes of the same size as the original pipes. For example, choose 1/2- or 3/4-inch PEX for the primary lines in a shower.

Use a half-inch PEX line to replace a half-inch copper line. You would use 3/4-inch PEX for 3/4-inch lines, etc.

Upsizing PEX in Your Shower

If your bathroom uses 1/2-inch piping, there’s nothing wrong with upsizing your bathroom run to 3/4 inch.

The only disadvantage of 3/4″ plumbing is that hot water takes a little longer to reach the bathroom. In smaller houses, a few seconds isn’t much of an issue. But in larger homes, this time can add up.

Dual Shower Systems

When working with PEX, it is crucial to utilize pipes of the appropriate diameter.

If your shower’s supply lines connect to a 3/4-inch line, you can get away with using 1/2-inch PEX.

But when installing dual shower systems, you’ll appreciate the extra water pressure from a 3/4-inch PEX pipe.

Gallons Per Minute

For more than 20 years, the federal government has limited shower flow to no more than 2.5 gallons per minute. 

In response to manufacturers’ making more luxurious shower fixtures with multiple nozzles, the Obama administration amended its rule limiting each fixture’s water-consumption rate.

During the Trump administration, the amount of water flowing from showerheads increased. However, under Biden’s leadership, those limits were reinstated.

In 2022, showerheads are limited to 2.5 GPM (gallons per minute), so you don’t need anything larger than ¾” PEX pipes for the highest allowable flow rate.

Installing PEX Tubing For Your Shower

Installing PEX Tubing For Your Shower

If you’re installing a new shower or replacing an old one, you may wonder how to run PEX tubing for your shower.

The good news is that PEX tubing is flexible and easy to install. Use a crimping tool specially designed for PEX tubing. You can also use a compression tool for PEX fittings. A crimping tool will be easier to use if you need to install the tube yourself, though.

Push fittings and push-to-connect fittings require no tools or rings for installation.


These are some commonly asked questions about using PEX for shower installations.

Can I run 3/4 PEX to a shower?

You can reduce 3/4 PEX to 1/2 or use only that size to save space and money. However, most plumbing fixtures—like sinks, toilets, and tubs—need full-sized piping so they can accommodate enough water pressure for their purposes.

Where is PEX not allowed?

You should not use PEX in unheated areas like a garage or crawlspace. It also should be avoided in areas where condensation is likely such as a basement.


PEX is a form of plumbing that contains no copper, lead, or other potentially harmful substances and is easy enough for anyone to install. When installing a new or replacement water line, install 3/4-inch PEX tubing for your shower. 

It’s the standard size for showers and provides plenty of water pressure. If you need a larger or smaller line, PEX is easy to cut and mold into whatever shape you need it to be.

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