PEX Piping 101 – What is PEX Pipe: How and When to Use It

PEX piping is the biggest evolution to plumbing since the “outhouse” became the “in-house!”  Although it may be fairly new to novice DIYers, it has been around since the 1960’s.  It was made big in the U.S. in the early 1990’s, about 15 years after it had already been in the European market.  So what is PEX pipe?

What is PEX Pipe?

PEX pipe is a cross-linked, high density, polyethylene.  In layman’s terms, it is a flexible yet durable tubing of plastic, made to withstand high temperatures and high pressure.

The word PEX is an acronym.  The “PE” stands for polyethylene and the “X” stands for the process of cross linking.

Pros and Cons of PEX Pipe

Pros

• Flexible – Can bend around corners and other obstacles allowing for less connection points and directional fittings
• Freeze Resistant – Because of its flexibility, PEX pipe can expand and contract during hot and cold temperatures, which prevent it from cracking
• Scale and Chlorine Resistant
• Doesn’t Corrode
• Doesn’t Develop Pinholes
• Cost Effective
• Allows for Quicker Installation
• Can be Used for Both Potable and Non-Potable Plumbing Applications

Cons

• Can NOT be used for outdoor use
• Exposure to UV light weakens the material
• Vulnerable to exposure of oils, benzene, and pesticides within the ground, that can leach into the pipes

Is PEX Pipe Suitable to use for Drinking Water?

This is one of the most controversial topics or questions out there when it comes to PEX pipe. And while I have read a many articles siting evidence on both sides, all of those articles I read pre-date this article done by the NSF International and published on December 16, 2016.

NSF International was founded in 1944 and orginally named National Sanitation Foundation. Manufacturers, regulators and consumers look to NSF International for the development of public health standards and certification programs that help protect the world’s food, water, consumer products and environment.

Now here at Tools 4 Guys, we are not recommending you use or don’t use PEX piping for your potable water. That is a personal decision for you and your family, but we do want to provide resources that may educate you on this topic, and help you make that decision.

Based on the article, there over 140 PEX piping products, made by 27 companies, that are certified for potable water applications. Regardless of what you think about PEX pipe drinking water safety, keep in mind, as a nation we used lead pipes for over 60 years, until we decided to stop. I am not condoning the lead pipe use or the PEX pipe use for potable water, I am merely stating that as a nation, we have used what was best at the time.

Tips and Tricks for Working with PEX Pipe

Tip #1

When going around hard right, 90 degree angles/corners, use the 1/2 in. Plastic Polymer PEX Pipe 90-Degree Bend Support with Mounting Bracket, so the pipe doesn’t kink. For us to fit them in the studs, like shown below, we used a dremmel to take off the mounting bracket, as shown below, with the red arrow.

Tip #2 – How to Install Pex Fittings

Use the PEX Crimp Tool for Cinch Clamps. It really is as easy as the picture looks below.

Just in case, if the pictures above don’t paint a thousand words, here is a video below, showing how to install pex fittings.

Tip #3

Allows for slack, even use an expansion loop, if needed, to allow for the expansion and contraction of the pipe during hot and cold temperatures.

Tip #4

I know this one probably goes without out saying, but just in case, I will say it anyway…use blue for cold water, red for hot water.

Tip #5

When feeding the tube through a 2×4 make sure to drill the hole bigger to allow for the contraction and expanding of the pipe. You can also use PEX pipe abrasion/suspension clips to help prevent the pipe from rubbing back and forth on the wood.

Tip #6

What if I mess up on a crimp ring, how do I get it off? This is probably one of the most questions that I get, and I believe it is easier to explain with the video below.

https://www.youtube.com/watch?v=p__lQH8V2Nw&t=82s

PEX Pipe in Action

Here is a job my dad, Ruben Cancino, and my brother Brandon Cancino, did when we were updating a shower in one of my older homes.

You can see in the picture below, there were two different pipes we had to run. The bottom one where we used PVC, was a drain pipe coming from the sink, and the top one, which is where we used PEX pipe, was the water pipe going to the shower head.

We used PVC in the bottom one because there were already existing PVC fittings on both ends of the drain. But even though we installed twice as much PEX pipe, length wise, than we did PVC pipe, the PEX installation was literally about 3 times faster than the PVC installation. You can read more below on the differences between the two pipes, but this is why I am a big fan of the PEX pipe.

How Does PEX Pipe Compare to Copper Pipe?

PEX pipe has a much less risk of leaks happening because it does not require nearly as many fittings as copper pipe. This also reduces the labor cost for installation, making PEX pipe more cost effecient than copper pipe.

PEX pipe has the flexibility to expand more than copper pipe making it more freeze-resistant because PEX pipe doesn’t degrade like copper pipe, it is starting to become an industry standard.

PEX pipe is safer to install because it doesn’t require a torch to solder the copper pipes together, again, making PEX pipe quicker and easier to install, cutting labor cost down significantly.

There are three areas that copper pipe has an advatage over PEX pipe:

1. Copper pipe is not as susceptible to rodent dame as PEX pipe
2. Copper pipe does not get UV damage as does PEX pipe
3. PEX pipe can rub against a harder surface as the water is turned on and off, causing a leak, but this can be easliy avoiding using the 90 degree bend support, as shown in the image above, or you can use PEX pipe abrasion/suspension clips, (link this to clips), to prevent chafing when going through or around wood.

How Does PEX Pipe Compare to CPVC Pipe?

When it come to PEX pipe vs. CPVC pipe, the advantages are similar to that of copper pipe. PEX pipe is so flexible, bend radius for 1/2″ PEX is 3 1/2″, that it can go around bends and corners, and easily adjusts to shifts in alignments, that it requires up to 70% less fittings, depending on the job size.

Although, PEX fittings are 2-5 times more expensive than CPVC fittings, the required amount of fittings with PEX pipe, is around 3-5 times less depending on the job size, than that of CPVC pipe. Also, because installation requires even less time for PEX pipe when compared to CPVC pipe, the total overall job cost with PEX pipe, is substantially less than the total job cost for CPVC pipe.

Other factors are similar as well when comparing the two. PEX pipe is more freeze resistant than CPVC pipe, can withstand higher temperatures, and fewer fittings means less chance of leaks.

PEX pipe also doesn’t require the use of cement glue to connect the fittings together unlike CPVC pipe. Now some would argue that you don’t need a tool, like the crimping tool, with CPVC pipe, like you do with PEX pipe, but I would argue that you still need tools for CPVC pipe, like a saw or pipe cutter, and the crimping tool doesn’t have an experiation date like the cement glue, and it works in freezing temperatures or in moisture, unlike the cement glue.

The main advantage that CPVC pipe has over PEX pipe, is that it can be used outside because CPVC pipe is not susceptible to UV rays and it is more stable for outside use. (see picture of water hose plumbing job)

Cost Comparison: CPVC vs. Copper vs. PEX Pipe

To do a cost comparison, let’s assume a job of 100 feet, from end to end, each having to round a 90 degree bend, using 1/2 inch pipe. Keep in mind,

CPVC	Copper	PEX
Piping Cost: $37.50 (1/2″x10′) 10 Fitting Cost: $1.80 (1/2 90 Degree Elbow) Tools Required: CPVC Primer & Glue $7.70	Piping Cost: $136.20 (1/2″x10′) 10 Fitting Cost: $4.16 (1/2 90 Degree Elbow) Tools Required: Torch $29.99, Silver Solder $18.16	Piping Cost: $27.66 Fitting Cost: Crimp Ring $5.48 Tools Required: Cimp Tool $29.99
Total Cost = $47.00	Total Cost = $188.51	Total Cost = $63.13

Keep in mind, in the above job example, although CPVC comes in about $16 less, notice, that on both CPVC and the copper pipe, someone will have to purchase 10 separate 10 foot pieces because unlike PEX tubing, it is not common for CPVC nor copper pipe, to come in a roll of 100 feet.

This means this job will also require 10 different connections, where fittings, primer, and glue will be needed, requiring more time and adding labor costs. This is where PEX really becomes the winner in overall job cost.

Home Advisor estimates that the average cost of a plumber can range from $45-$200 per hour. The average of that range is $145 per hour. And like I mentioned above in our rehab in updating our old shower, the CPVC piping portion took 3 times as long and we only used half as much pipe as we did for the PEX portion.

Therefore, with the job example above, of the 100 foot with a 90 degree bend, with CPVC it could be a 3-6 hour job, whereas the PEX pipe, only a 1-3 hour job. This adds an additional labor cost to the CPVC job of $435-$870 and the PEX job an additional $145-$435. The labor time and cost for copper pipe would be comparable to CPVC as well.

So whether you hired someone for the job or decided to do it yourself, either way you would be saving money, time, or both by using PEX pipe or tubing as opposed to CPVC or copper.

In Conclusion

Hopefully you can see why PEX pipe has been revolutionary to the plumbing industry and why we here at Tools 4 Guys, are a big fan of it. I mean installation time is cut down by around 50% – 75%, installation costs are less expensive than other pipe installations, and there is a less chance of your pipes cracking or bursting from a freeze…what’s not to like?

Please comment below if this article was helpful to you or if you have any other PEX pipe questions whatsoever, we are happy to help.

 

We Get the Job Done,

Ruben, Jason, Brandon, and Aaron Cancino
Co-Owners
www.tools4guys.com