This article detailed PEX flexible water pipe systems. Al’s Plumbing, Heating & A/C in Plano, Texas is near your home in Wylie, TX; Murphy, TX; and Rowlette, TX. We service all homes in southern Collin and Denton Counties with no travel charges. Al’s provides Full-Service Plumbing Maintenance, Repairs & Replacements for every plumbing component in your home. Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters. Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing. We will arrange an appointment at your convenience.
Al’s also provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps. Additionally, we sell & install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).
This Is Part-2 Of Our Two-Part Article. For Part-1 Click Here: AlsPlumbing.com Pex Water Pipe Part-2
Repiping An Existing Home With PEX Costs 1/3 — 1/2 Less Than Copper *4
HERE’S WHY:
- PEX pipe material is much less expensive than copper.
- PEX Installs Easier And Faster:
- PEX repiping can run through the attic in DFW homes.
- Repiping with copper will be done under the slab. This requires tunneling under the slab to gain access.
- Because PEX can bend somewhat — it can accommodate minor direction changes without using a fitting (shown in photo below).
- Copper requires a fitting at every direction change.
- In some instances — a single piece of PEX pipe can run from the water supply to the fixture. Copper pipe is sold in specific lengths, and another pipe must be added for a longer distance.
- PEX is quickly connected to fittings with a crimp-ring — or with a “push-to-connect” fitting (shown in photo at the top of this article). Copper must be soldered at every connection.
Image Source: ShutterStock
Shown: PEX Water Pipes Being Installed In A New Home’s Attic
Note: PEX attic installations are available in some locations in the southern U.S.
Repipe Cost Example — Copper Vrs. PEX Water Pipe *4
$8,000 to $10,000 — cost to replace old water pipes with copper pipes for a 1,500-square-foot, 2 bath home. **
$4,000 to $6,000 — cost to replace old water pipes with PEX with a manifold system (more on manifold systems later). **
** Source: https://www.bobvila.com/articles/pex-vs-copper/
**1 Source: https://www.epa.gov/ground-water-and-drinking-water/basic-information-about-lead-drinking-water#getinto
** Source: https://agrilifeextension.tamu.edu/library/water/drinking-water-problems-corrosion/#:~:text=What%20health%20problems%20can%20corrosion,liver%20and%20kidneys%20over%20time.
*** Source: https://corrosion-doctors.org/Pollution/lead.htm#:~:text=Copper%20pipes%20have%20replaced%20lead,water%20in%20U.S.%20homes%20today.
*4 Source: https://plasticpipe.org/pdf/tn-53-pex-chlorine-ratings.pdf
** Source: https://www.pexuniverse.com/pex-tubing-technical-specs
*** Source: https://www.popularmechanics.com/home/how-to/a1053/4202333/
*4 Source: https://www.bobvila.com/articles/pex-pipe/
*5 Source: https://www.copper.org/applications/plumbing/techcorner/electrolysis_cause_copper_tube_fail.html
PEX BENEFITS FOR THE PLUMBER (resulting in lower costs to the homeowner):
Here’s Why:
PEX pipe is less expensive. PEX flexible water line is 1/3 — 1/2 cost of copper pipe (installed).
PEX is easier and faster to install than metal or rigid plastic pipe — because there are fewer fittings and fittings are completed much easier and faster than with copper.
PEX can bend (into a wide-radius turn) — reducing the number of fittings.
PEX can be maneuvered around obstacles that would require several fittings when using a rigid pipe.
PEX doesn’t require connections to be soldered (like copper pipe) or glued (like rigid plastic). Connections are completed in seconds with PEX. PEX has fewer connections and fittings.
With a manifold system, some PEX water lines don’t have fittings — one piece of PEX pipe goes from the manifold to the faucet.
Because PEX is flexible — it’s sold in large spools. This allows for any length of PEX pipe to be installed without joints.
PEX BENEFITS TO THE ENVIRONMENT:
Polyethylene is a byproduct of oil or natural gas that was extracted for energy uses — so PEX doesn’t require the extraction of natural resources (like copper).
PEX manufacturing doesn’t require a lot of energy. Copper manufacturing requires a large amount of energy.
PEX is lightweight and is sold in large spools. Copper is heavy and sold in certain lengths. These reasons make shipping copper use more fuel.
PEX has insulating properties that reduce heat loss (from hot water lines) — by up to 15% as compared to copper (depends on outdoor temperature).
PEX May Have Been Slower To Be Adopted In The U.S. Due To Concerns About Chlorine Levels In Our Drinking Water.
- Some early PEX pipe deteriorated slightly when exposed to the high chlorine levels common in US water supplies. That problem was minimized by adding antioxidants during the manufacturing of PEX.
- To compute the resistance of PEX piping to chlorine — the American Society of Testing and Materials (ASTM) has created a Standard Test for PEX pipe and Systems to Hot Chlorinated Water (ASTM F2023). The test is a 50 year lifetime.
- A second (and more prevalent) problem was with early BRASS FITTINGS failures. Those earlier brass fitting contained too much zinc. As water flowed them — the zinc in the fittings leached away. This weakened the fittings due to a process called “dezincification”. Over time, some of those early fittings corroded and began leaking.
Click Here To See An EARLIER Brass PEX Fitting That Corroded & Began Leaking Due To DeZincification: Corroded & Leaking EARLIER Brass PEX Fitting
- Brass pipe fittings are manufactured with added zinc to increase the strength of the brass. Because the corrosion of brass is dependent on increasing amounts of zinc — the recommended zinc content is 15-19%. To reduce cost, early fittings manufacturers use zinc levels of 35%+. A zink level higher than 19% will cause dezincification — and low-quality brass fittings will corrode and may begin leaking.
- Look for the “ASTM F1807” AND/OR National Sanitation Foundations: “NSF PW” imprint on brass fittings. This ensures the fitting meets or exceeds their standards. If you don’t see either the ASTM or the NSF stamp — it’s best to assume that brass fitting doesn’t meet their standards.
TIP: Pay a little more to get a brass fitting with 1 or both imprints. Pay a little more yet, and get stainless steel fittings.
Click Here To See ASTM 1807 Rating Stamped On a PEX Brass Fitting: Brass PEX Fitting with ASTM F1807 Imprint Shown
Click Here To See The “NSF PW” Imprint On A Brass PEX Fitting: Brass PEX Fitting with NSF PW Imprint.
The following were some problems were associated with early versions of specific types of PEX plumbing pipes systems.
- PEX-A Manufacturers: Uponor/Wirsbo & Rehau. Problem: Dezincification of fittings (AquaPEX only).
- PEX-B Manufacturers: Zurn & Viega. Problem: Dezincification of fittings.
- PEX-C Manufacturers: Nibco/CPI/DuraPEX. Problem: Cracked & leaking PEX pipe.
- PEX-AL-PEX Manufacturer: Kitec/IPEX. Problem: Dezincification of fittings. Note: PEX-AL
NOTE: PEX-AL-PEX uses 2 layers of (same or similar) PEX pipe — WITH a welded aluminum tube reinforcement between the inner and outer layers. The inner and outer PEX layers are bonded to the aluminum tube using a melt-adhesive.
Additional Potential Concerns With Copper Water Pipe
Image Source: ShutterStock
Shown: New Copper Water Pipes
Copper’s Expected Lifespan: Up To 70 years. PEX is 50+ years. Copper offers up to a 40% longer lifespan — at up to double the (installed) cost or higher.
Acidic Water And Copper Pipes ( water with a pH < 7 is considered acidic)
Copper’s lifespan will be reduced if the water is acidic. Acidic water corrodes copper pipes (PEX pipe doesn’t corrode). Without treating acidic water, copper’s lifespan could be less than PEX. **2
If copper pipes corrode — copper may leach into the water. ** 2 PEX Water Pipe is resistant to corroding when exposed to acidic water.
NOTE: Water’s acidic level can be reduced with a whole-house water-neutralizer (more on this below).
Image Source: ShutterStock
Shown: Corroded Copper Water Pipe
Hard Water (high lime content) And Copper Pipes
Copper allows limescale build-up (from hard water) inside of the pipes. PEX Water Pipe is resistant to limescale build-up from hard water.
NOTE: Hard water lime build-up can be reduced with a whole-house water-softener.
Image Source: CanStockPhoto
Shown: Hard Water Lime Build-Up (green or off-white in the pic) On A Bathroom Faucet
Research Studies About Chlorine Affecting PEX
Because concerns exist about the effect of chlorine in the water, some independent studies have been performed. These research studies were viewed as flawed and/or didn’t reflect the typical use of water in a home (details below).
1. Report Name: “Influence of chlorinated water on mechanical properties of polyethylene (PEX — flexible plastic pipes) and polyvinyl chloride (PVC – rigid plastic pipes) pipes.”
Authors: B. Kowalska, T. Klepka, & D. Kowalski from Lublin University of Technology, Poland.
This study used these concentrations of chlorine:
- 4 ppm – EPA Maximum Chlorine Limit Allowed ***
- 70 ppm (parts of chlorine within a million parts of water)
- 400 ppm
- 4,000 ppm
Why This Study Isn’t Relevant: These levels of chlorine tested don’t reflect any U.S. drinking water. At chlorine levels as high (as in the test) — water could kill anyone who drank it.
The U.S. Environmental Protection Agency (EPA) States:
- At 30 ppm of chlorine — chest pain, vomiting, and cough occur.
- At 46-60 ppm — toxic pneumonitis and pulmonary edema (fluid build-up) occur.
Source: https://19january2017snapshot.epa.gov/sites/production/files/2016-09/documents/chlorine.pdf
** Source: https://www.witpress.com/Secure/elibrary/papers/UW16/UW16006FU1.pdf **
*** Source: https://www.cdc.gov/healthywater/drinking/public/chlorine-disinfection.html#:~:text=What%20are%20safe%20levels%20of,considered%20safe%20in%20drinking%20water.
2. Dr. Andrew J. Whelton of Purdue University in Layfette, IN performed the first U.S. Research Study (published 2014) — on 6 brands of PEX pipes — and their effect on the quality of drinking water. The team investigated tap water quality in a new PEX plumbing system. For 30 days. The team monitored new PEX pipes — over that time, both odor & total organic carbon (TOC) levels dropped for all brands of pipes. Note: TOC is the amount of carbon found in an organic compound — and is often used as a non-specific indicator of water quality.
Wheaton said:
- “Manufacturers need to do a better job cleaning their products before they provide them to the consumer.”
- “Homeowners who have PEX pipes should flush them.” This may be good advice if the home has been unused for a period of time — otherwise, daily use should provide sufficient flushing — (this comment is from this blog’s author).
- “1 PEX pipe brand caused 1 chemical (used in PEX production) — to exceed a drinking water health standard in the State Of New Hampshire. However, no such federal drinking water standard exists.”
- “If there is a history in your area of failed & leaking copper pipes (caused by corrosive water) — installing copper may not be the best choice.”
The National Sanitation Foundation (NSF) Identified Several Limitations With This Study:
- Non-standard methods of testing pipe were utilized.
- Test samples were exposed to conditions that do not reflect any real-life conditions in the U.S.
- Quantification of chemical extractants were not reported.
- Assessment of potential health effects attributable to reported chemical extractants was not performed.
- Controls or reference materials, when measuring the loss of chlorine residue, were not reported.
- A US EPA taste and odor method was used in a manner for which it was never intended.
- The source water control was not analyzed for samples taken in a building.
Source: https://d2evkimvhatqav.cloudfront.net/documents/nsf_reviews_studies_pex.pdf
Tasha Stoiber, a senior scientist at the Environmental Working Group explains: “From Dr. Whelton’s studies — we don’t have clear answers, as there is not a lot of long-term data.” After 30 days, some PEX pipes’ measurements were above the EPA’s odor threshold. Similar findings occurred from homes where pipes were 1 and 2 years old. The real takeaways from Whelton’s research are not so much for consumers, but for pipe manufacturers. I think the top takeaways from the blog piece were that more transparency and testing should be required from pipe manufacturers.
*4 Source: https://www.fondriest.com/news/not-drop-drink-plastic-pipes-leaching-chemicals-drinking-water.htm
*4 Source: https://www.purdue.edu/newsroom/releases/2014/Q4/drinking-water-odors,-chemicals-above-health-standards-caused-by-green-building-plumbing.html
Another Likely Reason PEX Was Not Readily Adopted In The U.S. — Was The Polybytelene (PB) Water Pipes Disaster.
From the mid 1970’s to the mid 1990’s, 6–10 million homes had POLYBUTYLENE (PB) flexible water pipes installed. Most of these homes were in the sun-belt, Mid-Atlantic & Pacific northwest. PB pipe & fittings failed in most homes — as a result of chlorine levels in U.S drinking water (up to 4 ppm of chlorine) that exceeded PB’s tolerance limit (2 ppm of chlorine). The chlorine caused the PB pipes & their plastic fittings to oxidize (become brittle) and begin cracking from inside to outside. Often, the cracks made it all the way through the pipe or fitting — and it began leaking.
PB pipe is nearly always gray. PB usually has a stamp reading “PB2110”. The brand “Quest” or “Qest.” is also stamped on the pipe.
Click Here To See A PB Water Pipe With Both The Brand Name “Qest” & “PB2110 Stamps: Photo Of PB Water Pipe
Click Here To See Polybytelene Water Pipe With Pin Holes: PB Pipe With Pin-Holes
Click Here To Read OUR Article About Polybutylene Pipes: AlsPlumbing.com Polybutylene Pipes Disaster In The U.S.
This article detailed PEX flexible water pipe systems. Al’s Plumbing, Heating & A/C in Plano, Texas is near your home in Wylie, TX; Murphy, TX; and Rowlette, TX. We service all homes in southern Collin and Denton Counties with no travel charges. Al’s provides Full-Service Plumbing Maintenance, Repairs & Replacements for every plumbing component in your home. Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters. Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing. We will arrange an appointment at your convenience.
Al’s also provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps. Additionally, we sell & install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard) and Coleman HVAC (same company as York HVAC).