The Best Underground Insulated PEX-Inclusive Buying Guide

The Best Underground Insulated PEX

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There is a variety of piping available, but to select the best insulated PEX, outdoor boiler pipe, outdoor furnace pipe, or thermal PEX pipe, consider the handy guide to choose the best type per your desired criteria and fitting location.

Check The Great Underground Insulated PEX on market

It might be tricky to compare the PEX types. So, to make it easy, we have brought this inclusive buying guide to make the selection process done quickly.

You can also go with homemade insulated PEX pipe if necessary but keep the prime features to be considered for the PEX to work well.

What is PEX, and why to choose it?

PEX (polyethylene cross-linked) piping is among the most popular residential plumbing systems. It is a corrosion-free, waterproof, flexible piping material with better flexibility requiring frequent support. Due to its beneficial features and pros, they are considered the best to opt for RPS.


PEX-A tubing

  • Method Of Manufacturing- The peroxide method opts for the manufacturing of PEX-A.
  • Suitability for Underground Burring-  Yes
  • Application- a. hot and cold water plumbing b. open-loop heating system
  • Pros-  it is highly flexible
  • Cons- 
  • A. you might experience chemical leaching issue b. it’s the most costly PEX among the types.

PEX-B tubing 

  • Method Of Manufacturing– The silane method opts for the manufacturing of PEX-B.
  • Suitability for Underground Burring- Yes
  • Application- a. hot and cold water plumbing b. open-loop heating systems
  • Pros -High bursting pressure and rigid
  • Cons–  a. Stiff                b. high prone to coil memory

PEX-C tubing 

  • Method Of Manufacturing– The irradiation Method opts for the manufacturing of PEX-C.
  • Suitability for Underground Burring-  No
  • Application– It is applicable for closed-loop heating systems, baseboards, radiators, radiant floor heating, and snow melting.
  • Pros- Eco Friendly 
  • Cons– Cracking Issues
  1. Waterproof 

If you are purchasing the best insulated PEX, choose the PEX that is forever waterproof. In the case of low-quality pipes, leakage may occur.


To choose an insulated PEX, check the product description to confirm its waterproof nature.

  1. Low Heat Loss 

The best insulated PEX is the one that possesses minimum heat loss. An insulated pipe will be fit for use to avoid heat loss.

Standard Heat Rating 

The best PEX pipe must not lose heat more than one degree over 200 feet. If this specification is not satisfied by the PEX, do not purchase it. 


Choose the PEX that possesses desired heat loss rating for conserving most of the heat.

  1. High Performance 

To select the best insulated PEX for a wood boiler, consider the product with a high-Performance Record. Some top brands own over a million sold products with nill failures. The better the product, the better will be its performance.


Always purchase the product from a top manufacturer with high performance and product rating records.

  1. Suitability  

Check suitability before opting for an insulated water pipe underground or pre-insulated PEX pipe for outdoors underground. Type B PEX is considered rigid and should be opted as per desired usage criteria (underground).


Select a suitable, insulated PEX tubing for better and long-lasting work.

  1. Quality

The higher the product quality, the better its performance. Do not compromise on the quality of your insulated PEX. It will be easily damaged and may cause leakage or loss of heat. 


A brand that ensures its quality as its supreme priority is a better option.

  1. Budget/ cost 

Various types of PEX tubings are available in the market. Type A is considered the most expensive among them. Consider your budget before opting for the insulate PEX type. Do not get tricked by a low-quality PEX at a lower price. You can suffer the negative consequences of poor quality PEX after use.

  1. Durability 

A durable PEX is of prime importance because it is employed underground for direct burial. 

A better quality PEX must possess a life expectancy of 40-50 years. 


Select a highly durable insulated PEX to make it stay long-lasting.

  1. Non-Corrosive Materials

Choose the PEX made of non-corrosive materials, limiting the rust and corrosion of the piping. Select the piping with a better expansion, making them anti-cracking and anti-freezing underground.


To avoid underground issues, select the best material PEX required for the task.

  1. Chlorine and Oxidative Resistance

The PEX is considered best if it possesses chlorine and oxidative resistance. It means the piping does not degrade while in contact with chlorine.

  1. Highest Degree Of Cross-Linking 

The higher the cross-linking in PEX, the better the PEX piping leading to better insulating nature.


Select the PEX with the highest degree of crosslinking to make it work best in harsh conditions.

  1. Eco-Friendly 

We should always consider our environment into consideration before opting for any product. It should be our top criteria for selecting a beneficial and eco-friendly product. To choose the best insulated PEX, consider its eco-friendly nature before purchasing and using it. PEX c tubings are considered the most eco-friendly insulated PEX to use.

  1.  Pex Nature

The softer the PEX piping, the better it’s considered for the desired task. The type A PEX is less rigid than others. Consider type B if you want to opt for an underground insulated PEX because it is of desired nature.

  1. Brand 

A variety of brands are offering the best type of PEX, but which brand to choose? It’s simple! Compare the products of different brands with customer reviews and product ratings to find the best insulated PEX to purchase. 


The top-rated brand with high ratings should opt for product purchases.

  1. Warranty 

The high-quality PEX comes with an Industry-Leading warranty with full replacement coverage with a labor facility. 

Each PEX type may possess a different warranty period. Warranty is of prime importance and provided by most top-rated manufacturers. Select the one with a better warranty period.


Check the product description to find the warranty period of the desired product.

Things to Avoid While Purchasing Underground Insulated Pex

Before purchasing an insulated PEX, do not opt for;

  • Black underground PEX pipe 
  • Foam-filled insulation PEX pipe


 They are not suitable for underground fittings and should always be avoided.


What type of PEX is best for the underground?

PEX-B is the best underground tubing due to its flexible and rigid nature compared to other types. It’s also budget-friendly and affordable for purchasers. It is manufactured by moisture or steam cross-link after it’s added into the desired tube.

Is PEX safe for the underground?

PEX-A and PEX-B are suitable for underground fittings because of their flexible and rigid nature that can abide the underground fluctuations. They can better handle water freezing and thawing when buried below the frost line. 

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