Discover the Pros and Cons of Using PEX Pipe Underground: A Comprehensive Guide

PEX pipe underground plumbing has become increasingly popular in recent years due to its many benefits, such as its flexibility, durability , and resistance to freezing. However, when it comes to using PEX pipe underground plumbing in outdoor settings, there are some potential challenges and risks to consider. This article will explore why PEX pipe underground plumbing can be problematic outdoors and discuss the effects of UV light , chlorine damage, and the risk of rodents and pests on PEX pipe underground plumbing.

We will also delve into the suitability of using PEX pipe underground plumbing underground and provide tips on how to protect PEX pipe underground plumbing in outdoor settings. Whether you’re a homeowner or a professional plumber, this article will provide valuable insights and guidance on using PEX pipe underground plumbing in outdoor environments. So, let’s dive in and discover how to navigate the potential pitfalls of PEX pipe underground plumbing in outdoor settings.

The most important facts in a nutshell

  • PEX plumbing has both benefits and downsides, and can be problematic outdoors due to UV light damage, chlorine damage, and the risk of rodents.
  • While there are arguments for using PEX plumbing underground, there are also arguments against it.
  • To protect PEX pipes in outdoor settings, options include direct burial underground method, running PEX piping in UV resistant material, and coating PEX pipes with latex paint.

pex pipe underground

1/14 Benefits of Using PEX Plumbing

With its numerous advantages, PEX plumbing reigns as the favored option for plumbing endeavors. Its pliability surpasses that of copper pipes, eliminating the need for elbow fittings and allowing for effortless bending and curving. This enhanced flexibility also translates into fewer joints and fittings, thereby minimizing the likelihood of leaks.

Unlike metal pipes, PEX plumbing boasts a diminished susceptibility to corrosion and leaks. The robust plastic material utilized in PEX pipes exhibits resistance to rust and corrosion, guaranteeing an extended lifespan for your plumbing system. Consequently, this affords substantial savings on repairs and replacements in the long haul.

Furthermore, PEX plumbing proves to be a cost-effective alternative. It generally carries a lower price tag than copper pipes and necessitates less time and labor for installation. As a result, overall project costs are reduced, rendering it an ideal choice for both residential and commercial applications.

In essence, PEX plumbing presents heightened flexibility, reduced risk of corrosion and leaks, and cost-effectiveness, making it a pragmatic and dependable option for any plumbing endeavor.

If you’re wondering whether it’s safe to bury PEX underground, check out our article “Can You Bury PEX Underground” for all the important information you need to know.

2/14 Downsides of Using PEX Plumbing

While PEX plumbing offers many benefits, it does come with a few drawbacks. One challenge is the availability of PEX materials, which may not be easily accessible everywhere. This can lead to delays and increased costs for your project.

Additionally , PEX pipes have the potential to freeze and crack , resulting in costly repairs and water damage. To mitigate this risk, it is crucial to properly insulate or bury the pipes. Another consideration is that PEX pipes may cause reduced water flow, particularly if you have multiple fixtures connected.

To maintain optimal water flow, adjustments or additional measures may be necessary. Despite these challenges, with careful planning and precautions, a successful PEX plumbing installation can still be achieved.

pex pipe underground

3/14 The Effect of UV Light on PEX Pipes

PEX pipes, like delicate creatures basking in the sun, are vulnerable to the harmful effects of UV light. The relentless rays can turn these once sturdy pipes into fragile beings, prone to damage and decay. With time, the very essence of their strength can be eroded, leading to leaks and bursts that disrupt the peace.

But fear not, for there is a solution to shield these pipes from the wrath of the sun. Enter UV resistant materials, the guardians of PEX pipe longevity. Like a suit of armor, these materials provide an extra layer of defense, preserving the pipes’ strength and durability amidst the harsh outdoor elements.

Yet, vigilance must be our constant companion. Regular inspections and maintenance are essential, as they allow us to catch the subtle signs of UV damage. Discoloration, brittleness, and changes in water flow can all be ominous omens, urging us to take action.

In such times, it is wise to seek the guidance of a professional plumber, for they possess the knowledge and skill to mend the wounds inflicted by the sun. And to prevent future battles, preventive measures must be taken, fortifying the pipes against the relentless assault of UV rays. By adhering to these noble precautions, our PEX pipes shall stand tall and proud, defying the odds and continuing to perform their duty in the great outdoors.

How to Safely Install PEX Plumbing Underground: A Step-by-Step Guide

  1. Assess the location: Determine if the PEX plumbing will be installed in an outdoor setting or underground.
  2. Consider UV protection: If the PEX plumbing will be exposed to direct sunlight, use the direct burial underground method or run the PEX piping in UV resistant material.
  3. Protect against chlorine damage: If the PEX plumbing will be in contact with chlorine, consider coating the pipes with latex paint for added protection.
  4. Connect PEX to PVC: If connecting PEX pipes to PVC pipes underground, follow the step-by-step guide to ensure a secure and reliable connection.

4/14 Chlorine Damage and PEX Plumbing

Protecting Your PEX Pipes from Chlorine Damage Preserving the longevity of your PEX pipes is crucial, as chlorine can pose a threat to their durability. However, fear not, for there are effective measures to counteract this potential harm. By installing a trustworthy filtration system, you can eliminate chlorine from your water supply and safeguard your plumbing.

Investing in a reliable filtration system is a wise choice, as it shields your PEX pipes from the corrosive effects of chlorine. This proactive approach not only spares you the expenses of future repairs and replacements but also ensures the longevity of your plumbing system. If you have PEX plumbing, it is imperative to prioritize the installation of a high-quality filtration system.

This simple yet essential step will safeguard your investment and maintain the optimal condition of your plumbing for years to come.

5/14 The Risk of Rodents and Pests to PEX Pipes

Safeguarding your PEX pipes from rodents and pests is crucial. Regularly check for signs of damage like gnaw marks or punctures and take immediate action if found. Utilize pest control methods, seal entry points, and employ traps or repellents near your plumbing system.

Stay proactive in preventing harm to your pipes and keep unwanted visitors at bay.

Things to Consider When Using PEX Plumbing Underground

  • PEX plumbing is a type of plumbing system that uses cross-linked polyethylene (PEX) pipes.
  • One of the benefits of using PEX plumbing is its flexibility, which makes installation easier and allows for fewer connections.
  • Another advantage of PEX plumbing is its resistance to corrosion, which helps extend the lifespan of the pipes.
  • However, one downside of using PEX plumbing is its susceptibility to damage from UV light.
  • Exposure to UV light can cause PEX pipes to degrade and become brittle over time.
  • Chlorine can also damage PEX pipes, so it’s important to consider the water treatment methods when using PEX plumbing.
  • Another potential issue with PEX plumbing is the risk of rodents and pests chewing through the pipes, especially in outdoor settings.
  • While PEX plumbing is generally suitable for underground use, there are some considerations to keep in mind.

6/14 The Case for Using PEX Plumbing Underground

In recent years, the rise of PEX plumbing has been nothing short of extraordinary. Its popularity stems from a multitude of reasons, each more compelling than the last. To begin with, PEX pipes possess an unrivaled resistance to corrosion, making them a dependable option for any underground application.

While metal pipes may succumb to the relentless forces of moisture and other elements, PEX pipes stand strong, unyielding to the test of time. Moreover, the flexibility of PEX pipes is a true marvel. They have the remarkable ability to adapt to shifting soil conditions, defying the very laws of nature.

As the ground moves and settles, PEX pipes remain unscathed, unbreakable and unyielding to the immense pressure. But it doesn’t stop there. The lightweight nature of PEX plumbing elevates its appeal even further.

Installation becomes a breeze as these pipes effortlessly maneuver through the tightest of spaces. The need for extensive excavation is minimized, causing minimal disruption to the surrounding area. In essence, PEX plumbing embodies the trifecta of qualities that homeowners and contractors seek: corrosion resistance, flexibility, and ease of installation.

If you find yourself pondering the possibilities of underground plumbing, look no further than PEX . It is a choice that will undoubtedly stand the test of time.

pex pipe underground

7/14 The Case Against Using PEX Plumbing Underground

When it comes to using PEX plumbing underground, there are some drawbacks to consider. One concern is the potential for damage from rocks or tree roots, as PEX pipes lack the same level of protection as other options. This can result in expensive repairs.

Additionally, PEX pipes may struggle with temperature fluctuations and extreme weather conditions, leading to issues like pipe expansion or contraction. Moreover, PEX plumbing may require more frequent inspections and repairs, resulting in higher maintenance costs. Ultimately, while PEX plumbing is well-suited for indoor use, it may not be the optimal choice for underground applications due to the risk of damage, limited protection against temperature changes, and increased maintenance expenses.

Keep these factors in mind when selecting the right plumbing solution for your needs .

8/14 Using the Direct Burial Underground Method

When it comes to installing PEX pipes outdoors, many people opt for the direct burial underground method. This method is not only straightforward but also saves both time and money. Additionally, it offers exceptional protection against potential damage.

To utilize this method effectively, it is essential to select appropriate PEX pipes specifically designed for burial. Furthermore, one must dig a trench with proper insulation and take necessary precautions, such as incorporating a cushion and visible markers. Ultimately, this approach proves to be a practical and cost-effective solution for various outdoor plumbing projects.

By following these steps diligently , one can ensure a successful implementation of this technique .

When installing PEX pipes underground, it’s crucial to protect them from potential damage. In this video, we’ll explore effective methods to safeguard PEX pipes and ensure their longevity. Discover expert tips on how to protect your PEX pipes underground.

YouTube video

9/14 Running PEX Piping in UV Resistant Material

Protecting PEX piping from UV damage is essential. UV exposure can weaken and make the pipes brittle over time. By using UV resistant material , you create a shield against harmful rays, preventing discoloration and degradation.

It also ensures the durability and longevity of the piping, making it capable of enduring outdoor conditions . To implement UV resistant material , select a high-quality one specifically designed for outdoor use, cut it to the right length, and securely attach it to the PEX pipes. Ensure it is sealed and protected.

By using UV resistant material , you enhance the performance and lifespan of your PEX piping. Whether it’s an outdoor plumbing project or an upgrade, opting for UV resistant material will yield optimal results.

If you’re curious about using direct bury PEX, check out our article “Direct Bury PEX” for all the information you need on this convenient plumbing solution.

pex pipe underground

10/14 Coating PEX Pipes with Latex Paint

Preserving the Integrity of PEX Pipes: The Power of Latex Paint Safeguarding your outdoor PEX pipes is of utmost importance, and one effective solution lies in the application of latex paint. This straightforward method yields a multitude of advantages, ensuring the longevity and fortification of your pipes. Latex paint acts as a formidable barrier, shielding the pipes from the detrimental effects of UV rays.

These rays, if left unchecked, can render the pipes brittle and prone to degradation. By generously applying a layer of latex paint, you can thwart discoloration and fading, guaranteeing the resilience and integrity of your pipes. To expertly coat your PEX pipes, embark upon these simple steps: meticulously cleanse the surface, administer a generous layer of latex paint, and patiently allow it to dry in its entirety.

This coating provides unwavering protection against the perils of moisture, effectively averting damage and corrosion. In essence, the act of coating PEX pipes with latex paint bestows an array of benefits, particularly for outdoor usage. Whether it be shielding against UV radiation or supplying a robust barrier against moisture, this uncomplicated measure significantly prolongs the lifespan of your pipes.

By adhering to the proper coating procedure , you can embrace tranquility , knowing that your PEX pipes are adequately shielded and primed to endure the elements .

Did you know that PEX pipes can expand up to three times their original size when exposed to freezing temperatures?


My name is Warren and I am a professional plumber licensed and insured in the State of California. I have been in the business for over 10 years and have undertaken small and large projects including bathroom renovation, toilets, garbage disposals, faucets, sinks and kitchen plumbing jobs. This site is based on my experience with toilets. I have installed the best brands and models in all sizes and shapes. I hope this helps you with the unbiased information that you need to make the right decision.


11/14 Step-by-Step Guide to Connecting PEX to PVC Underground

In the depths of your underground plumbing system, lies a potential threat – leaks. But fear not, for I shall guide you through the intricate process of sealing the elusive PEX to PVC connections. Are you ready?

Let us embark on this journey together: First, equip yourself with the necessary tools and materials: a PEX crimping tool, PEX and PVC fittings, and pipe thread sealant. Next, wield the mighty PVC pipe cutter and slice the PEX pipe to your desired length. Remember, precision is key, so ensure a clean and straight cut.

Now, embrace the PEX fitting and slide it onto the end of the PEX pipe. Push with purpose, my friend, ensuring it is fully inserted and securely seated. With the PEX and fitting in perfect harmony, it is time to unleash the power of the PEX crimping tool.

Squeeze, compress, and watch as the metal ring envelops the fitting and PEX pipe, creating a fortress of security. Follow the sacred instructions bestowed upon you by the manufacturer, for they hold the key to proper crimping technique. Ah, the moment has come to summon the pipe thread sealant.

Apply it to the mighty male end of the PVC fitting, for it shall aid in the creation of a watertight connection between the PEX and PVC pipes. With grace and determination, insert the PVC fitting into the awaiting PEX fitting. Tighten the bond, my friend, and give it a gentle twist.

Let the sealant dance between the fittings, ensuring an even distribution of its power. Now, we must inspect our creation. Look closely, for any sign of imperfection or weakness.

If you spy a leak or a loose fitting, fear not. Simply tighten the loose ends or seek the wisdom of a professional plumber for guidance. By following these sacred rites and taking the necessary precautions, you shall forge a connection that defies the forces of nature.

Leaks shall tremble, and your plumbing system shall stand strong and unwavering.

pex pipe underground

12/14 Choosing the Best PEX Fittings for Underground Use

Selecting the right fittings for underground PEX plumbing installation is crucial. Here are three important factors to keep in mind:

1. Protection Against Corrosion: The underground environment can be harsh, so it’s essential to choose fittings that are resistant to corrosion. This will prevent any issues caused by moisture and soil conditions over time.

2. Compatibility is Key: It’s important to ensure that the PEX and PVC fittings you choose are compatible. Different properties require compatible fittings to create a secure and leak-free connection.

3. Durability and Quality Matter: Look for fittings that are made from high-quality materials and have been tested for long-term performance. This will ensure that your underground PEX plumbing system will last. By considering these factors, you can select the best fittings for your underground installation.

Investing in high-quality, corrosion-resistant fittings will provide you with a reliable and efficient plumbing system that will stand the test of time.

Comparison of Piping Materials for Underground Use (Tabelle)

Piping Material Pros of Using the Material Cons of Using the Material Suitability for Underground Use UV Resistance Resistance to Chlorine Damage Vulnerability to Rodents and Pests Recommended Protection Methods Recommended Fittings for Underground Use Signs of Damage Specific to the Material Steps to Take if Damage Occurs
PEX Pipe Flexible, easy to install, resistant to corrosion, lower cost Not suitable for high temperatures, may degrade in sunlight Yes Medium High Low Direct burial, UV resistant material PEX fittings Cracks, leaks, discoloration Repair or replacement of damaged section
PVC Pipe Durable, lightweight, resistant to chemicals, low cost Can become brittle over time, limited UV resistance Yes Low Medium High Direct burial, UV resistant material PVC fittings Cracks, fractures, warping Repair or replacement of damaged section
Copper Pipe Durable, corrosion resistant, long lifespan Higher cost, may require professional installation Yes High High Medium Direct burial, corrosion-resistant coatings Soldered or compression fittings Pinhole leaks, corrosion Repair or replacement of damaged section
Galvanized Steel Pipe Strong, durable, resistant to corrosion Prone to rust and corrosion over time Yes Low High Low Direct burial, corrosion-resistant coatings Threaded fittings Rust, leaks, discoloration Repair or replacement of damaged section
CPVC Pipe Corrosion resistant, suitable for hot water applications Not suitable for high temperatures, limited UV resistance Yes Low Medium Medium Direct burial, UV resistant material CPVC fittings Cracks, fractures, warping Repair or replacement of damaged section
HDPE Pipe Highly durable, resistant to chemicals, long lifespan Can be expensive, not suitable for high temperatures Yes High High Low Direct burial, UV resistant material HDPE fittings Cracks, leaks, discoloration Repair or replacement of damaged section

13/14 How to Identify UV Damage on PEX Pipes

Look out for these signs to identify UV damage on PEX pipes. Discoloration or fading of the pipes is a clear indicator. UV light exposure can make them lose their vibrant color, becoming dull or faded.

Brittleness or weakened strength in the pipes is another sign. UV light can degrade them, making them more prone to cracking or breaking . If they feel weak or inflexible, UV damage is likely.

Pay attention to water flow and pressure . UV damage can internally degrade the pipes, affecting your plumbing system’s functionality. Decreased water flow or pressure fluctuations may be due to UV damage to the PEX pipes .

Regularly inspect visually, check for brittleness, and monitor water flow and pressure to effectively identify UV damage on PEX pipes. If you notice any of these signs, consult a professional plumber for evaluation and necessary repairs. To prevent future UV damage, consider using UV-resistant materials or coating the pipes with latex paint.

pex pipe underground

14/14 What to Do if Your PEX Pipes Have UV Damage

Repairing PEX pipes damaged by UV rays is crucial to avoid further issues. Here’s how you can fix them: Begin by inspecting the pipes for discoloration, fading, brittleness, or weakened strength. If the damage is minor, you can handle the repair on your own.

Use a PEX cutter to cleanly remove the damaged section of the pipe. Smooth out any rough edges or burrs on the remaining pipe and the new piece of PEX pipe. Connect the new piece of PEX pipe to the existing pipe using PEX fittings and a crimping tool.

Follow the manufacturer’s instructions carefully for proper installation. For severe damage or if you’re unsure about the repair process, it’s advisable to seek assistance from a professional plumber. They possess the necessary expertise to handle any complications.

To prevent future UV damage, consider using UV-resistant materials for your PEX pipes. This can involve burying the pipes in a UV-resistant conduit or applying a protective coating like latex paint. Regular inspections and maintenance will also help detect and address any potential UV damage early on.

If you’re looking for tips and tricks on toilet rough plumbing, check out our article “Toilet Rough Plumbing” to make sure you’re on the right track for your bathroom renovation project.


In conclusion, PEX plumbing can be a great option for indoor plumbing due to its flexibility , durability, and resistance to corrosion. However, when it comes to using PEX pipes outdoors, there are some potential issues to consider. UV light can cause damage to PEX pipes over time, and exposure to chlorine can also be problematic.

Additionally, the risk of rodents and pests damaging the pipes is a concern. While there are methods to protect PEX pipes in outdoor settings, such as using the direct burial underground method or running the piping in UV resistant material, it is important to weigh the pros and cons before deciding if PEX plumbing is suitable for underground use. If you do choose to use PEX pipes underground, it is crucial to properly connect them to PVC pipes using the appropriate fittings.

Signs of UV light damage on PEX pipes include discoloration, brittle or cracking pipes, and a decrease in water pressure. If you notice these signs, it is important to take action to prevent further damage. Overall, this article provides valuable information for readers who are considering using PEX plumbing underground, allowing them to make an informed decision based on their specific needs and circumstances.

For more helpful articles on plumbing and home improvement topics, be sure to explore our other resources.

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