Pipes freeze when the temperature goes below 32 degrees Fahrenheit, especially in uninsulated or exposed areas of a property. Common vulnerable spots include basements, crawl spaces, attics, and exterior walls. When water inside the pipes freezes, it expands which increases the risk of a pipe bursting.

When to Call a Professional Plumber in Bethel Park?

Call a professional plumber if: Your pipes are frozen, and no water is coming out; You notice signs of a burst pipe, such as low water pressure, water pooling, or unusual pipe noises; Your water heater stops working or struggles to produce hot water; Your sewer or drains are clogged, leading to backups and unpleasant odors; You suspect a hidden leak inside your walls or ceiling; You experience repeated plumbing issues.

PEX vs Copper: Which Is Better for Repiping a House?

Oct 26

5 min read

Neither PEX nor copper is better for every house. PEX is flexible plastic tubing that handles freezing better, while copper is rigid metal that resists UV light and heat, does not burn, and is fully recyclable. For a whole-house repipe in a cold-winter area like the South Hills, the choice usually depends on where the pipes run, how exposed they are to cold or sunlight, and what the walls and ceilings will allow.

Whichever material you pick, repiping in Allegheny County comes with paperwork. The Allegheny County Health Department requires a plumbing permit for any plumbing that is installed or altered, and the plumbing plan has to be approved before work starts. The back of that plan asks for a drawing showing the location, connections, and types of materials being installed, so the pipe choice is part of the paperwork, and a final inspection is required. This post compares PEX and copper on freeze resistance, durability, sunlight, safety, and installation, and covers what to know about older copper systems before you decide.

What Are PEX and Copper Pipes?

PEX (cross-linked polyethylene) is a flexible plastic tubing used for hot and cold water supply lines. Copper tubing is a rigid metal pipe that, the Copper Development Association says, joins with capillary fittings.

Both are used for drinking water lines. Uponor, a major PEX manufacturer, says its PEX pipe has been in service for potable water plumbing since 1993. The Copper Development Association, the copper industry's trade group, describes copper tube as manufactured to well-defined composition standards and marked with permanent identification.

Which Handles Freezing Better, PEX or Copper?

PEX has the edge in freeze tolerance. Uponor says its PEX-a pipe can expand up to three times its diameter without cracking or bursting, has been tested through more than 400 freeze and thaw cycles, and stays flexible down to minus 40°F. It contrasts that with rigid copper, which does not expand and contract the same way.

That does not make PEX freeze-proof. Uponor's own language says the pipe helps reduce the risk of damage, not that it eliminates it, and a frozen line of any material still stops delivering water.

In the Pittsburgh area, freezing is a regular concern. NOAA's 1991 to 2020 climate normals for Pittsburgh International Airport put the average January temperature at 28.8°F. For pipes that run through exterior walls, crawl spaces, or unheated basements, freeze tolerance is a practical reason to consider PEX. Our guide on how to avoid winter pipe freezes and leaks in Bethel Park covers protection steps for either material.

Which Lasts Longer and Holds Up Better?

Both materials come with strong claims from their manufacturers:

Copper: The Copper Development Association cites excellent resistance to corrosion and scaling, high mechanical strength, high-temperature resistance, and lifetime resistance to UV degradation.
PEX: Uponor says its PEX-a meets the highest requirement for chlorine resistance at end-use conditions 100 percent of the time at 140°F, and backs its AquaPEX pipe and ProPEX fittings with a 25-year transferable limited warranty.

Water chemistry, installation quality, and how the pipes are supported all affect how long a system lasts in a real house. Warranty terms vary by manufacturer and product line, so ask which brand of pipe and fittings your plumber installs and get the warranty details in writing. If your current pipes are already showing trouble, read how to know if your pipes need replacing for the warning signs.

Does Sunlight or Heat Matter?

Sunlight is a real limitation for PEX. Uponor rates its white AquaPEX pipe for one month of UV exposure and its red and blue pipe for six months. PEX that will be exposed to daylight, such as near an unfinished window or outdoors, needs protection. Below ground is a different story: Uponor says its PEX pipe is approved for direct burial in soil or concrete.

Copper has no such limit. The Copper Development Association lists lifetime resistance to UV degradation among copper's advantages, along with high-temperature resistance. It also notes that copper tube will not burn, support combustion, or decompose to toxic gases.

Which Is Easier to Install in an Older House?

PEX often has the edge on installation time. Home Depot's PEX vs copper comparison says copper usually requires more material and longer installation time than PEX. Because PEX bends, it can also follow curved paths that rigid pipe cannot.

Copper has installation strengths too. The Copper Development Association says copper tube can be bent and formed to eliminate some elbows and joints, join with capillary fittings into smooth, strong, leak-proof joints, and does not need the heavy wall thickness of threaded iron pipe.

What About Older Copper With Lead Solder?

If you are replacing old copper rather than galvanized pipe, age matters. The EPA explains that the Safe Drinking Water Act banned the use of pipe, fittings, solder, or flux that was not lead-free in the installation or repair of plumbing providing drinking water after June 1986, and it now caps solder and flux at 0.2% lead. Copper systems installed before that could have lead solder at the joints, which is worth knowing when you weigh spot repairs against a full repipe.

What Should You Ask Before Repiping?

A repipe is a big job, so a few questions up front help:

Which rooms and walls need to be opened, and who handles patching?
Will any new pipe be exposed to sunlight or unheated spaces?
How will the new lines connect to the water heater and main shutoff?
Who pulls the Allegheny County Health Department permit, and when is the final inspection?
Does the quote include all fixtures, valves, and connections?
Will the old pipe be removed, abandoned in place, or capped?

For more on local permit rules, see do you need a permit for plumbing work in Pittsburgh. If you are repiping after a failure, what to do when a pipe bursts in your home covers the first steps.

FAQ

Is PEX or copper better for cold climates?

PEX handles freezing better. Uponor says PEX-a can expand up to three times its diameter without cracking, though no pipe is freeze-proof.

Can PEX be exposed to sunlight?

Only briefly. Uponor rates its white PEX for one month of UV exposure and its red and blue pipe for six months.

Does copper pipe contain lead?

Copper tube itself is not the concern. The EPA says lead-free requirements for solder and flux took effect after June 1986, so older copper systems may have lead solder at the joints.

Do I need a permit to repipe a house in Allegheny County?

Yes. The Allegheny County Health Department requires a permit for plumbing that is installed or altered, with a plan approved before work begins and a final inspection.

Is PEX approved for drinking water?

Yes. Uponor says its PEX pipe has served potable water plumbing systems since 1993.

Does copper burn in a house fire?

The Copper Development Association says copper tube will not burn, support combustion, or decompose to toxic gases.

Repiping and Plumbing Repair From a Bethel Park Team

All Pro Plumbing Heating & Cooling handles a full range of plumbing repairs and installations for homes across Bethel Park, the South Hills, and Allegheny and Washington counties, and it uses acoustic detectors, thermal imaging, and moisture meters to track down hidden leaks. Registered Master Plumber John Oakes founded the company in 2006 as a home-based family business, and it now works from its own office on Library Road with 10 local employees. You get upfront, per-job pricing before any work begins. See plumbing services and leak detection.

Visit All Pro Plumbing or call 412-595-8204 today. Contact us for more information.