Is Inch PEX Pipe Big Enough For A Shower? (Find Out Now!)

Ryan Womeldorf
by Ryan Womeldorf
Plumbing work is never easy, especially when it comes to fitting pipes for your shower. Luckily, you can use ½” PEX pipes for your shower, but only if your pipes tie into a ¾” line. Whether it be making the proper connections or fitting your pipes, follow along as we explore how to install ½” PEX pipes for your shower.

Whether renovating a current shower or building a new one entirely, it is important to ensure that the water wiping is up to proper standards. That means using the right materials for piping water into your bathroom.

If you are going to use PEX, a flexible plastic, you need to make certain that you are using the right size PEX. So long as the supply lines for your shower tie into a ¾-inch line, then ½-inch PEX should be fine for the job. It may not be quite big enough for a dual shower system, in which case you would need ¾-inch PEX.

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Will ½-inch PEX Work for a Shower?

Water flow is one of the most important aspects of a shower (and any water fixture, really). To get the proper water flow going into your shower, you will need to install water lines that run into the fixture itself.

It is a good idea to go with ½-inch or ¾-inch PEX for the main lines. The good rule of thumb and standard is to simply replace the old water supply lines using PEX that is the same size. So, if the old line was ½-inch, use ½-inch PEX. For ¾-inch lines, you would use ¾-inch PEX, and so on.

Is PEX A Popular Option?

Traditionally speaking, copper piping has been the popular choice for running water lines into a home. The lead pipes of old could lead to corrosion and contamination of the water. That said, copper piping is not the cheapest nor easiest material out there.

PEX, which is cross-linked polyethylene, has become one of the primary choices for these applications, particularly in residential systems. That is because it is not only flexible, but affordable and easy enough that DIYers can use it.

When used in tandem with a manifold system, PEX reduces the potential for leaks and eliminates splicing. Even better, PEX comes in a wide array of sizes to best fit individual household fixtures and to accommodate for water pressure.

How Do You Size the PEX You Need for Home Plumbing?

While that is a good rule of thumb to follow, it can be quite helpful to know other methods for sizing out the PEX that you use. Since PEX is becoming more and more commonly used due to its durability and flexibility, it helps to know how to size it out.

There are a few ways that you can accurately size the PEX needed. Among the important factors are whether or not a manifold system is being used, the PEX diameter itself, the water pressure and any potential pressure drops.

PEX Diameter

When you go to buy PEX, the most important number to look for is the “nominal” sizing. This is a construction standard that lets you know that this pipe is compatible with fittings that are of the same size.

PEX tubing comes in rolls as small as 50 feet but can be purchased up to 1,000 feet in length at a time. Their diameters come as small as 3/8-inch all the way up to a full inch when it comes to residential applications.

For the most optimal water flow in residential settings, PEX that is ½-inch to ¾-inch in diameter will be best for the main water lines. As stated above, always replace the old lines with new lines that are of the same size.

Manifold System

Due to the continuous and flexible nature of PEX, plumbers find that they are able to run this tubing directly to each fixture from a water-supply manifold. For residential whole-house manifolds, you will see red valves on one side and blue on the other. These are your hot and cold indicators.

When you run your water supply lines, the rule of thumb is to go from a wider line and transition to a narrower one, but don’t go the other way around. The valve sizes on the manifold let you know what the largest compatible PEX size is.

So, if you have a manifold with ¾-inch valves, then you can install PEX tubing that is ¾-inch or smaller. Whenever you install smaller tubing, you will need to apply to reduce fittings as well.

Water Pressure

More and more, homeowners are looking to conserve water. They are not just being kind to the environment, they also want to reap the savings that come with that conservation. By running narrow PEX lines into certain fixtures, the potential for reduced wastewater is there. That said, not every fixture benefits from having narrower PEX lines.

Think about it like this: most homeowners aren’t going to wait 15 minutes for their bathtub to fill. That is why running a ½-inch PEX tubing at a minimum is a good idea. Dishwashers and washing machines also benefit from the ½-inch lines.

Showers and sinks, on the other hand, are water guzzlers. You can conserve some water by running 3/8-inch lines to them. The reason being that their refill rate is not as important, so a smaller line is possible with their installations.

Pressure Drops

Keep the distance from the manifold in mind. The general rule is that, the greater the distance to the fixture, the wider that your PEX tubing should be. There are also designated lengths for each thickness of PEX tubing.

For a 3/8-inch line, you can run it up to 250 feet. A ½-inch line, meanwhile, will carry necessary water pressure as far as 350 feet. Lastly, ¾-inch tubing is required for a 500-foot line. Just check out the recommended maximum lengths when you look at the PEX packaging.

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What are the Benefits of PEX?

Though touched upon briefly above, there are quite a few benefits to implementing PEX piping in your next bathroom installation. You may not necessarily go wrong using a copper pipe installation, but that typically is not quite as easy to perform as a DIYer.

PEX has Great Flexibility

Without a doubt, one of the greatest benefits of using PEX piping is its flexibility. Using galvanized steel or traditional copper for water main lines was the traditional means of doing things due to durability and longevity.

But PEX is far more flexible than any of these, which makes installation far easier because they can connect to a manifold and then wind through floors and walls. Even better, they don’t need to be interrupted, meaning they can run directly into the fixtures.

This method is called “homerun” plumbing. It basically means taking a single length of PEX for each of the cold and hot water connections, which eliminates the potential for risk at the various connections that would have been required for copper or galvanized steel.

Easier Installation

There are more than a few setbacks when it comes to running copper piping. The various connection points, the need to solder, and the cost are some of the biggest detriments of using copper piping.

PEX does not require soldering as it is in one long, flexible piece. Even better, it is expandable. Whereas copper or steel may potentially crack under extreme low temperatures, PEX can expand and contract based on the weather with no issue. All this means a smoother installation with fewer pieces required.

Cheap and Durable

PEX does not corrode. Both steel and copper pipes can suffer from corrosion, leading to water supply contamination and leaks. PEX also eliminates that “water hammer” sound that can be common with metal piping, staying quiet.

Perhaps most notable is that it is substantially cheaper than metal piping. While cost may not be the most important thing, it certainly matters. Installing PEX piping can save substantially on your budget while delivering a wide array of benefits.

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Ryan Womeldorf
Ryan Womeldorf

Ryan Womeldorf has more than a decade of experience writing. He loves to blog about construction, plumbing, and other home topics. Ryan also loves hockey and a lifelong Buffalo sports fan.

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