Why You Must Never Splice Underground PEX Pipe

By:Warren Walborn

Underground pipe carries your valuable heat from your underground pipe to your home and other buildings. There is considerable technology in this pipe - One thing we make sure of is that the PEX tubing inside the insulated pipe is a CONTINUOUS RUN. There are no splices in the PEX in the underground pipe.

This is crucial because a splice would be the point of greatest risk of a failure in the PEX, and in the waterproof outer casing.

The PEX cannot be spliced underground because PEX naturally expands and contracts. Since PEX will expand and contract 1-2.5" per 100ft of length with every 10°F changes in water temperature, it cannot be spliced underground because that splice location (or coupling) will fail from constant expansion and contraction as heat temps fluctuate drastically with an outdoor boiler system.

Yes, there are several PEX elbows and connections at the indoor plumbing locations, but since those are much shorter lengths of PEX, they can absorb the expansion and contraction without stressing the connectors. It is recommended to put an elbow just inside the home where the underground pipe emerges into the building that can absorb this considerable expansion and contraction.

Also, since the underground pipe outer casing must be waterproof, it is extremely difficult to splice the outer casing. We use only the highest quality outer casing, which is white on the outside. We are able to splice that at our factory if needed, but we are experts at making perfect water tight seals and it is very difficult to achieve a water tight seal in the field.

Therefore, there is a 100 percent failure ratio (or a ZERO percent success ratio) when attempting to splice underground pipe.

>>> If you are considering new underground pipe, do NOT buy black!

Black underground pipe is made of drain tile, and drain tile is not manufactured to be waterproof. 

Why is this a problem? If water leaks into your underground pipe, then it will suck a lot of heat out of your underground pipe. Some customers report that their boiler water is 180 degrees leaving the boiler going into the underground pipe, but when it arrives in the house, they have already lost 40 degrees!  This is an enormous waste of wood and money!  (And time to cut, split, and stack all that extra wood!)

Again, do NOT buy underground pipe that is black.

And never splice the underground pipe!

This way, we can help you save THOUSANDS on your heating bills for decades to come!

Call our office Monday-Friday 9am - 8pm ESTat (231) 221-0104.

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