PEX Supply Pipe: Everything You Need to Know
PEX supply pipe is the biggest revolution in plumbing since the flush toilet, and in this article we’ll answer the most common questions homeowners have about it and also give you some tips for working with it.
Which is Better – PEX or Copper?
- PEX is cheaper than copper. Half-inch PEX tubing costs about a third the price of copper. Some of the savings will be offset by the need for a special tool to install the fittings, but if you’re doing a medium to large plumbing job, you’ll usually save by using a PEX supply instead of copper.
- PEX fittings are faster to install than copper. If you use a manifold and ‘home-run’ system, it’s like running a garden hose to each fixture — super fast and easy. But even if you install PEX fittings in a conventional main line and branch system, the connections are quicker to make than soldering copper.
- A PEX supply won’t corrode like copper. If you live in an area with acidic water, copper can corrode over time. A PEX supply is unaffected by acidic water and is therefore a better choice in these areas.
What About PEX vs. CPVC?
Do I Need Special Tools?
No. You can use stab-in or compression fittings to make the connections. But they’re too expensive to be practical on large projects. For most PEX supply jobs, you’ll want to invest in a special tool to make connections. There are several PEX supply connection methods, but only two that are affordable enough to be practical for DIYers: crimp rings and cinch clamps.
Crimp rings are a band of metal, usually copper, that you slip over the fitting and compress with a crimp ring tool. The main drawback to the crimp ring method is that you’ll need either separate crimping tools for 1/2-in. and 3/4-in. fittings, or a universal tool with a swappable insert (not shown). This adds a little up-front cost to this method. A combo kit with interchangeable crimp jaws starts at about $100.
Cinch clamps work more like the traditional band clamps you’re probably familiar with. You slip the cinch clamp tool over the protruding tab and squeeze to tighten the cinch clamp. The same tool works for all sizes of cinch clamps. Cinch clamp tools start at about $40. We like the one-handed version shown in the photo because you can hold the ring in place with one hand while tightening it with the other.
The only other special tool you need is a scissors-like cutter for the tubing.
Check out Milwaukee Tools’ ProPex Cordless Pex Tool in this Stuff We Love video to learn more about what tools are out there.
How Do I Splice PEX Fittings Into My Existing Pipe?
Do I Have to Use Manifolds with PEX?
Manifolds look intimidating, but they actually simplify plumbing runs and reduce possible leaks by eliminating the need for tees and other fittings between the main supply line and the fixture.
Do I Have to Use Red for Hot and Blue for Cold?
Is PEX Reliable?
Which Tubing Should I Use for Interior Water Lines?
How Do I Connect PEX to my Plumbing Fixtures?
If you’re using a manifold system with valves, you may not need to install a shutoff valve at the fixture. Ask your plumbing inspector. We recommend adding one, though. It doesn’t raise the cost much and is more convenient than running downstairs to shut off the water when a repair is needed.
What About Expansion?
Will PEX Break or Split if it Freezes?
PHOTO: COPYRIGHT EASY HEAT INC.