Photograph of  this antiquated laundry sink with several unsanitary plumbing violations in view.Installation Specifications, Inspection & Testing Plastic Plumbing Piping & Connectors
Properties, Failures, & Standards for ABS CPVC PB PEX PVC Piping

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Plastic plumbing pipes:

Beginning here, this article series describes the properties of all types of plastic piping and tubing used in buildings for water supply, drainage, or gas or oil fuels, including ABS, CPVC, PB, PEX, PVC. We include information about failures and problems with some generations of plastic pipes (ABS, polybutylene) and we describe good building practice installation details where plastic piping is being installed.

Included is information about ABS, PB, Polybutylene, PEX, PVC polyvinyl chloride and other plastic piping materials. We discuss problems and class action claims for plastic pipe product failures including both the piping itself and its connectors or fittings for each of these materials where trouble has been found.

We also discuss ongoing or previous health & safety concerns raised for some plastic piping products. The articles at this website will answer most questions about plastic building water supply and building drain piping products, failures, and claims as well as many other building plumbing system inspection or defect topics.

Green links show where you are. © Copyright 2015, All Rights Reserved.

Plastic Water Supply & Drain Piping Types, Failures, Inspection, Diagnosis, Repair

Polybutylene water piping guidelines (C) Carson Dunlop Associates

Article Series Contents

As Carson Dunlop Associates point out in the Home Reference Book, as currently used in buildings:

Plastic water service piping may be made of

Plastic building drain piping may typically be made of

  • ABS - ABS PLASTIC PIPE FAILURES (black plastic drain piping or some water supply piping)
  • PVC - polyvinytlchloride pipe and pipe fittings (white plastic)
  • PB - polybutylene pipe and acetal plastic insert pipes - "PB plumbing"

Piping history of use (C) Carson Dunlop AssociatesMost plastic piping used outdoors is buried at least 18 inches deep. Exposed piping may be subject to mechanical damage and deterioration from sunlight.

Plastic supply piping is popular because it is less expensive and easier to work with than copper.

There are many types available including cross-linked polyethylene (PEX), polybutylene (PB), and chlorinated polyvinyl chloride (CPVC). - Home Reference Book, used with permission.

[Click to enlarge any image]

Contributions or comments are invited. CONTACT us to contribute.

As Carson Dunlop's sketch (above left) shows, plastic piping entered widespread use in North American beginning around 1965 and continues to the present.

ABS Plastic Pipe Failures, Leaks, Claims, Settlements

ABS Drain Piping (C) Daniel FriedmanComplete details are at ABS PLASTIC PIPE. Excerpts are below.

As our black ABS drain piping photo shows (above), some drain line leaks having nothing to do with product defects can occur in this system if the piping is not properly installed.

Field investigations of leak stains (as in our photo) as well as investigations of sewer gas odors (SEWER GAS ODORS) have traced these problems to failure to properly clean, prime, and glue the pipe joints during construction.

However, "All Black -hit," defective black ABS plastic waste pipe manufactured in the mid 1980's failed by cracking, as Cranor's photo below illustrates.

"All Black -hit," defective black ABS plastic waste pipe manufactured in the mid 1980's failed by cracking. The result was litigation and some damage settlements, but currently it is unlikely that a homeowner will find legal relief for newly-discovered ABS drain waste vent piping cracks and failures.

ABS Plastic Drain/Waste/Vent (DWV) pipe failure Brands

ABS drain pipe material failures were reported for pipe made between 1985 and 1988. [1][2][5][6][7] below

  • Apache ABS pipe failures: Apache Plastics defective piping was produced due to use of defective raw materials to make ABS DWV between January and May 1985. Not all Apache ABS DWV suffers the cracking failure problem, and less Apache ABS pipe defects are found than among the other manufacturers listed below.
  • Centaur ABS pipe: Centaur black ABS pipe was labeled with the company's name and was made between February and August 1985. Decoding for the date in data stamped on Centaur pipe: look at the production code found just past the UPC on the pipe, beginning with an "S"(1985) followed by 5 characters YMDDDP as follows:
    • Character 1: Year of manufacture: E=1971, F=1972, G=1973, etc. - an "S" = 1985 and a "T" =- 1986 - key problem years for ABS DWV piping defects.
    • Character 2: and Month of manufacture: D=Jan, E=Feb, etc. through O=Dec.
    • Characters 3, 4: Day of manufacture (2 characters) encoded as digits 1-0 corresponding to D-M respectively
    • Character 5: Production shift or Resin Lot code.
    • Character 6: used only for third party sales: Centaur also produced ABS piping for sale under other trade names. In that case Centaur advised that the company printed a "C" suffixed to the end of the product date code.
  • Gable ABS pipe failures: Gable plastics defective ABS piping was made during 1985 and 1986 and is very prone to cracking failures and leaks, again due to use of defective plastic raw materials.
    • Gable ABS pipe date of manufacture is stamped un-encoded onto the pipe
  • Phoenix ABS pipe, successor to Centaur Corp. issued defective, crack-prone ABS piping from January 1986 - October 1986. Phoenix used the same production codes (but the year will indicate it's Phoenix not Centaur).
  • Polaris ABS pipe, manufactured defective ABS piping between February 1985 and July 1985. Not all Polaris ABS piping made during this interval suffers the cracking failure, depending on variation in batches of purchased raw material.
    • Polaris ABS Pipe Date Encoding: nnnYY where
    • nnn = the numeric day of the year (001-365) and YY = the year in digits, such as 10085.
  • Spartan ABS pipe

More information: U.S. CPSC Hot Line: 800-638-8270

ABS Plastic Pipe Leak Failures Still Being Discovered

Cracked leaking ABS Drain Piping (C) Daniel Friedman John Cranor The House WhispererABS plastic drain and vent line failures are still being discovered, as John Cranor's photo from 2011 illustrates.

Home inspector John Cranor provided the photo at left of a cracked ABS drain line, commenting:

This photo of cracked ABS is damage that I feel has to be related to the defective ABS that was reported years ago. I am in VA and have inspected close to 6000 homes and this was the first I have seen this issue here. I saw at least six spots on the drain pipe in the crawl space that had similar cracking and white crusty residue like shown in photo.

I know there was once a lot of information out there about this issue but now I cannot find hardly anything. The website is now owned by some plumbing contractor and it has no useful information about ABS or its issue.

The seller of the property where I took this photo has some plumber saying there is nothing wrong and that he has never heard of a problem as I described. He claims the white residue is mud and that he could see no crack.

Spotting ABS plastic pipe cracking failures

Plastic drain pipe mixup (C) D FriedmanAlthough the cracked ABS drain line is quite visible in Mr. Cranor's photo (above), or in some areas where piping is exposed (photo at left) there may not be ready access for visual inspection of all surfaces of all of the plastic ABS drain lines in a building.

Here are some tips that can reduce (not eliminate) the chances of missing faulty black ABS plastic drains:

  • For houses built between 1985 and 1988, perhaps extending into 1993 or even later (to allow for use of in-stock older ABS piping), inspectors, building owners, and building buyers should be particularly alert for leaks in ABS black plastic drain, waste or vent piping. As we noted above, for buildings constructed outside of this time window drain lines may have other leaks and defects, regardless of faulty materials themselves.
  • Look for visible damage, leaks, leak stains, or loose pipes or fittings that may be moving due to breaks or cracks in the DWV piping. Remember to include inspection of the vent piping system, from on-roof, in the attic, and in other accessible areas. Keep in mind that if you find even one leak there is a high risk that there may be additional hidden leaks as well as future failures and leaks.
  • Look for product dates & manufacturer's codes indicating the problem brands of ABS piping, listed above. Experts report defective ABS piping products based on manufacturer's product codes and dates even if no leaks are observed at the time of inspection.
  • Look on the under-side of lateral drain line runs through the building for evidence of leak stains on the ABS piping itself - the actual crack may be difficult to spot but leak stains may be more obvious (see the photo above)
  • Look for water leak stains on building walls, ceilings, floors below ABS drain pipes on nearby building surfaces
  • Look for ABS drain line cracks at the glue-line joint in and look for mixed plastic types (white PVC, black ABS) on older buildings. Cracking ABS failures often occurred close to glued unions. Modern plastic pipe glues can handle and even joint both types of plastics, but at an older installation such as at the home above, where we see mixed plastics we pose the possibility that none of the mixed-type plastic pipe joints may be properly glued. This is not a problem peculiar to defective ABS but the two conditions may be found together.
  • Look for evidence of repeated prior repairs that may indicate recurrent cracking and leak failures in the piping system
  • Pressure test drain, waste, vent piping systems: for a system that is in doubt or where a hidden leak is suspected (perhaps where there are undiagnosed sewer gas odors), consider pressure testing the DWV piping. Pressure testing can also detect improper pipe joints such as failure to glue the joints properly.

ABS Class Action & Litigation

The prior class action litigation involved five of the six ABS pipe manufacturer's brands listed above: Centaur, Phoenix, Polaris, Gable, and Apache. (Spartan was excluded). We have not found evidence of an class action (June 2012). The attorney involved in prior actions, David Birke-White, indicated (paraphrasing) that defective ABS piping failures are a progressive problem and that piping that had not already failed will do so in the future.[1]

ABS DWV pipe failure references

  • [1] Mark Cramer, Tampa Florida, provided background information about ABS black plastic drain piping failures, including lists of problem pipe manufacturers, date encoding, and attorney's statements. 2/28/1997. Mr. Cramer is a Florida home inspector and home inspection educator. He is a frequent contributor to Mr. Cramer provided information based on "Inspector's Field Notes"™, William P Ball, Ed., 1996.
  • [2] John Cranor provided a photograph of failed ABS drain piping used above. Mr. Craynor, an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to
  • [3] P. Davis, B.E. Tiganis, L.S. Burn, "The effect of photo-oxidative degradation on fracture in ABSpipe resins", Polymer Degradation and Stability, Volume 84, Issue 2, May 2004, Pages 233–242
    Abstract: This work investigates ultraviolet (UV) degradation and its influence on fracture failure in acrylonitrile–butadiene–styrene (ABS) resins.

    Preliminary chemiluminescence assessment of coupon specimens indicates that degradation is restricted to the specimen surface, with a relatively rapid depletion of residual stabiliser compared to the bulk of the specimen. Fourier transform infra-red spectral analysis indicates that this surface-specific degradation forms photoproducts with the distortion of absorbance bands (corresponding to the trans CC unsaturation (vinyl) in polybutadiene (PB), and the 1,2-butadiene terminal vinyl C–H band), indicating bond unsaturation.

    These changes in chemical structure are attributed to cross-linking and chain scission in the PB phase. It is proposed that surface degradation after UV exposure promotes brittle behaviour and may therefore influence the failure mechanism of ABS pressure pipes under static loading.

    The effect of UV exposure in coupon specimens is compared to that of surface notching, and plane-strain fracture toughness tests are used to obtain an empirical relationship between exposure time and “equivalent” notch depth. By assuming that this relationship is independent of specimen geometry (i.e. degradation is restricted to the surface), a methodology for estimating the lifetime of UV-exposed ABSpipes is proposed.

    An analysis of DN100 Class 15 ABSpipes predicts that a transition to brittle fracture failure occurs after 137 years. However, it is recommended that the influence of pipe wall thickness on degradation kinetics be quantified.
  • [2] J. P. Lu, P. Davis, L. S. Burn, "Lifetime prediction for ABS pipes subjected to combined pressure and deflection loading", Polymer Engineering & Science Volume 43, Issue 2, pages 444–462, February 2003,
    Abstract As part of an investigation into the performance of acrylonitrile-butadiene-styrene (ABS) systems for water transportation, this paper presents a method for predicting the service lifetimes of buried pipes under in-service loading conditions. A linear fracture mechanics approach was used to analyze brittle failure initiating from adventitious flaws located at the bore surface of pipe.

    Failure criteria were determined using the time-dependent, quasistatic, plane strain fracture toughness of the ABS material, combined with empirical parameters that describe slow, steady crack growth. The expected operating conditions of a buried pipe were then separated into static loading contributions from internal pressure, diametrical deflection and residual stress.

    Idealized stress intensity factors associated with mode-I crack opening under each of these components were determined using a finite element analysis and superposed to describe the general case in service. The computed nett stress intensity factor was then combined with the previously determined fracture toughness and slow crack growth data in an algorithm to simulate incremental radial crack growth from the pipe bore.

    Predicted failure times compared well with an experimental model of expected operating conditions, which combined hydrostatic pressure and parallel-plate deflection loading of an internally notched pipe. The prediction method was also used to identify the factors that control the lifetime of a pipe in service. The influence of material visco-elasticity was investigated by simulating variations in fracture toughness and slow crack growth resistance.

    It was proposed that, in practice, these variations are governed by opposing changes in visco-elasticity. The effect of changing diametrical deflection and residual stress distribution were also simulated, allowing recommendations on pipe manufacture and installation conditions to be made.
  • [4] Lieff, Cabraser, Heimann & Bernstein, Attorneys at Law, "Lieff Cabraser represented plaintiffs who alleged that certain ABS pipe contained plastic resin that caused it to crack and leak."
  • [5] Bill Ball, "ABS Failure Video", Bill Ball Enterprises, 3104 O St., Sacramento CA 96186, Tel: 800-309-HOME.
  • [6] Note: the previous "Official website for the class action suit against ABS manufacturers" , with the official claim form and descriptive information: is no longer functional. The link at left produces a U.K. plumbing company.
  • [7] Redwood Kardon, "ABS DWV Pipe: reported defects", 1996,

PEX TUBING: Cross-Linked Polyethylene (PEX)

PEX Water Piping installation (C) D Friedman Galow Homes

Complete details about PEX are at PEX PIPING INFORMATION, Excerpts are below.

PEX and PB plastic pipe are used for water supply in buildings use mechanical fittings (crimp and compression type) and we have found some installers using PEX tubing in low temperature heating applications (see below). PEX piping is also referred to as "cross-linked polyethylene" piping or just "PEX".

Our photo (left) illustrates PEX water supply piping being installed in a New York home. Photo courtesy Galow Homes. Installing both building water supply piping and heating supply piping (and radiant heating) can be significantly faster using PEX tubing because of its ability to bend around turns, avoiding some elbows, 45's and other fittings.

PEX piping is used in both hot and cold water applications (see the blue and red colors below). By convention the builder uses blue PEX for cold water and red PEX for hot water supply piping lines.

Generally you will find PEX piping or tubing marked with the nominal pipe size, wall thickness, and pressure rating and other information (see the illustration just below).

Temperature and pressure ratings for PEX, according to Zurn Manufacturing's engineering specifications is 160 PSI at 73°F, 100 PSI at 180°F, and 80 PSI at 200°F.

PEX piping marking guide (C) Zurn Manufacturing

Illustration of PEX tubing markings - courtesy Zurn Manufacturing (permission requested 12/2010).

[Click any image or table to see an enlarged, detailed version.]

When installing PEX piping, care must be taken that the pipe does not contact heating ducts. If the pipe freezes, it is less likely to burst than and copper piping. Also, most types of plastic water pipe tend to sag and should be well supported by hangers.

Watch out: PEX plastic water piping should not be installed outdoors or exposed to sunlight for long periods. The red and blue PEX piping shown below (right) were delivering hot and cold water in a newly-constructed home. The larger black ABS plastic pipe is probably a drain line.

Watch out: do not use plastic piping nor any other type of piping in applications for which it was not intended, or the result could be dangerous. For example, do not use PEX tubing for LP or natural gas piping.

Polybutylene water piping guidelines Carson Dunlop Associates Plastic piping (C) Daniel Friedman

PEX Tubing Connectors: Types, Tools, Requirements

Watch out: a variety of patented PEX tubing push-fit and clamp connecting fittings (at least six types) and connector crimping tools are on the market. You may not obtain a proper and secure PEX connection if you mix tubing connector fittings and crimping tools improperly. We recommend choosing a specific connector type and crimping tool and using it consistently at a given plumbing installation.

See PEX BRASS CONNECTOR LEAKS for an update on field reports of de-zincification corrosion and leaks at brass PEX pipe connectors, elbows & tees.

Examples & Photographs of the various types of PEX fittings and the special tools used include:

PEX Clamp fitting installation (C) D Friedman

  • Clamp type PEX fittings (photo at left) using a brass connector and stainless steel clamp-rings (e.g. Hydro-Pex clamping tool). These connectors were in use in our PEX installation photograph above. Popular, easy to use.

    Note in our PEX photo at left that on the cold water (blue) Tee fitting one of the clamp fittings remains to be completed. (Photo courtesy Galow Homes).
  • Crimp type PEX fittings (photo at left - Crimp type PEX fittings in a Haddonfield New Jersey home) (e.g. Watts Radiant PEX cramping tool) using Hydro-Pex fittings.

    The copper crimp rings are used with most PEX connectors.
PEX Clamp fitting installation (C) D Friedman
  • Compression type PEX fittings (photo at left) (radiant heating and other applications) uses three parts (connector, compression ring or ferrule, threaded nut) to connect PEX tubing to a radiant heating manifold.

    Threaded nut and ferrule are used with an insert to prepare the tubing for connection to the manifold.

    No special tools are needed and compression type PEX fittings work with standard and Pex tubing.

Shark Bite type PEX fittings (C) D Friedman

PEX Tubing installation details (C) D Friedman
  • Expander type PEX fittings (photo at left, Expander type PEX fittings in a Tivoli NY home), e.g. ProPEX brass connecting fittings and the ProPEX expander tool from Uponor (formerly Wirsbo PEX fittings).

    The expander tool actually expands or "stretches" the PEX tubing to accept the connecting fitting. A ProPEX ring of larger diameter covers and completes the expanded fitting connection. Popular with professional plumbers.

    Our PEX tubing photo (left) illustrates three PEX installation details: use of expander-type PEX fittings, and at the photo bottom (blue cold water piping) a protective sleeve or bushing at the floor joist penetration, and a steel nail plate to protect the tubing from puncture by ceiling drywall (to be installed).

    Watch out: use only with PEX A-quality fittings. lower quality tubing will not make secure PEX connections with this method.

    Note: in best construction practices all holes drilled through structural floor joists (shown at left) would be made in the center of the joist, not near the bottom as in our photo.

  • Press-fit type PEX fittings from Wirsbo, Mr. PEX, and Viega. (do not assume you can mix fittings and tools among these three manufacturers). Use the Viega PEX press tool requires using Viega fittings, for example.

    The Viega press PEX fittings are sold separately from the required stainless steel press PEX rings OR you can buy Viega pex press fittings that include the crimp ring already combined with the fitting.

    When using the Viega method with the integrated fitting and crimp ring you'll need to look closely to assure that you have inserted the fitting fully into the tubing before crimping the sleeve using the Viega tool. Works with standard and Pex tubing.
Shark bite push fit plumbing fittings (C) D Friedman
  • SharkBite PEX push-fit fittings (photo at left) - push-in fittings (also work with copper and CPVC). No tools or rings are required.

    We used the SharkBite fitting shown at left to temporarily cut and discontinue active hot and cold water plumbing lines during a building renovation/addition project. The fittings avoided having to drain piping and solder end caps onto pipes that were later to be further cut back, excavated, and permanently capped below the slab.

  • PEX Tubing cutter - used to make a clean end-cut, e.g. Wirsbo (now Uponor) PEX cutter

Standards, Listings and Approvals for PEX Plumbing Systems

The following standards and building codes list at least some elements of PEX plumbing systems.

  • ANSI/NSF Standard 14 (NSF International)
  • ANSI/NSF Standard 61
  • ASTM F876 (American Society for Testing & Materials)
  • ASTM F877
  • ASTM F1807
  • CAN/CSA B137.5 (Canadian Standards Association)
  • California Plumbing Code - 2010
  • IPC (International Plumbing Code)
  • IRC (International Residential Code)
  • UPC (Uniform Plumbing and Mechanical Code)
  • U.S. State & Local Regulations or Canadian Provincial or Local Regulations

Plumb-PEX Plumbing System Class Action Settlement - PEX piping leaks

In March 2012 the U.S. District Court for the District of Minnesota court-ordered homeowner notification program was scheduled to begin. People who own or previously owned a building where Plumb-PEX plumbing components were installed are notified of a proposed class action settlement involving Radiant Technology, Inc. and Uponor, Inc who sold Plumb-PEX insert fittings and stainless steel PEX tubing clamps.

Those components may have leaked, or may leak, causing building damage. The defendants denied all claims of the lawsuit but have agreed to settle the case. [14][15]

Plumb-PEX Settlement Details

RTI Plumb-PEX Plumbing System fittings and components including

  • ASTM Standard F1807 brass insert fittings
  • Stainless steel clamps used with the installation of these components
  • Installed on or after 15 May 1999
  • Where a leak in the system [using those components] occurred or
  • Where water flow differential of 50% is found between hot and cold water supply lines feeding one or more fixtures


  • People or "entities" whose structure has already suffered a qualifying leak and have already paid for repairs

Plumb-PEX Settlement Provisions

The settlement reimburses for property damage caused by a qualifying leak in the Plumb-PEX installation, and it provides for possible repair or replacement of the RTI Plumb-PEX installation in structures suffering two or more "qualifying" leaks.

Watch out: If you are eligible for a claim under the Plumb-PEX settlement, you must file your claim within 18 months of the notification date of 22 March 2012

Also see PEX vs. Copper Water Supply Piping - health & other questions found below in the FAQs section of this article.

PB Pipe: Polybutylene Plumbing Plastic Pipe Use, Installation Specs, Failures, Leaks, Claims, Settlements

Plastic drain piping (C) Daniel Friedman

Complete details are at PB Polybutylene (PB) Pipes. Excerpts are below.

Thumbnail: Polybutylene (Polybutylene) Plumbing (plastic pipes): gray plastic water supply piping cracked, leaked, and resulted in a class action and settlement.

PB or Polybutylene pipe material (photo at left, center horizontal piping) is gray plastic water supply piping that racked, leaked, and its early use resulted in a class action and settlement.

In 1995 a $950 million class action settlement, Cox v. Shell Oil Company, provided relief for damage due to leaks in Polybutylene plumbing (PB Plumbing) within certain age constraints. Periodic notices were to be provided to homeowners over a 12-year period (ending ca. 2007) as follows:

Owners who purchased a house, mobile home, or other structure in the United States after August 21, 1995, provided that the structure contained polybutylene piping with plastic or metal insert fittings when they purchased it, are included in the class. These individuals may have been entitled to free replacement of their plumbing if it leaked previously or in the future.

The Polybutylene Pipe Settlement case is now closed. Homeowners whose structures still contain problematic versions of PB plumbing may nevertheless find that their building or mobile home is damaged by leaks and needs repairs. However there is no longer relief provided under the class action suit.

By 2010 it would be uncommon to find problematic plastic piping in buildings as we expect that where leaks were a problem, they have in many if not most installations, been discovered and repaired by now.

However home inspectors and home buyers as well as building maintenance staff need to be alert for discovery of older problematic or leaky plastic piping in buildings.

When we see several types (colors) of plastic piping mixed together, especially on older renovation or handyman plumbing jobs we worry that amateur work may have omitted use of the proper pipe glues and sealants.

PB polybutylene pipe failures noticeBut the majority of leak problems with polybutylene supply lines involve failure of plastic fittings. Fitting failure may lead to the need for system replacement.

This type of fitting was commonly used from the late 1970s until the late 1980s. Copper fittings were used in most installations from the late 1980s until the late 1990s. Failure of copper fittings is rare.

Failure of the actual polybutylene piping also seems relatively uncommon.

For at least some of the extensive plastic pipe failure claims, an important factor in the PBS pipe failure mechanism included water that contained significant levels of chlorine.

Polybutylene water piping guidelines (C) Carson Dunlop AssociatesSee Chlorine - sources in drinking water for related information.


Connections for PB or polybutylene water piping can be made without soldering, and the pipe is easy to work with, as Carson Dunlop's illustration (left) shows.

Our photo (below) shows hot and cold water piping using these materials and fittings in a new building.



PEX Tubing installation details (C) D Friedman

Polybutylene Piping failures:

Polybutylene water piping guidelines (C) Carson Dunlop Associates

Polybutylene piping has been (PB) the source of considerable controversy due to failed fittings, especially first generation plastic fittings.- Home Reference Book, used with permission.

In this article (below) we include links to information about PB piping failures, claims, and litigation. -DF






PB Pipe: Polybutylene Pipe Failures, Claims, Litigation, Contact Information

White PVC Drain Pipe Break (C) Daniel FriedmanOur photograph of a broken white Schedule 40 PVC sewer line in a crawl area (left) illustrates what can happen to this material if a sewer line is blocked and exposed to freezing.

  • PB (polybutylene with mechanical fittings) Piping leaks: especially in mobile homes and in the U.S. South, for example trailers and double-wides throughout Florida that were piped with this material - per M Cramer. See "Polybutylene Piping: Time Bomb?" Daniel Friedman, Journal of Light Construction, August 1996 [Technical Q&A].
  • Plastic Supply and Drain Piping Failures: leaks,
    lawsuits, settlements
  • If plastic water piping is installed, such as polybutylene water supply piping, it should be at least 18" from the water heater.
  • New mobile home and trailer units: 3/4" supply piping, must be installed a minimum of 6" off the ground; a shutoff valve is required. Also
    see WATER SHUTOFF VALVE LOCATION, USE where to find and how to turn off the main water valve in buildings

Recommendations (Specifications) for PB Polybutylene Water Pipe Installation

Industry associations, including the Polybutylene Product Line Committee of the Plastic Pipe & Fittings Association have made recommendations for successful installation of polybutylene piping systems, including those listed below. Frankly by 2010 we were never seeing PB installations in buildings at which all of the recommendations below were followed and OPINION it may be that industry experts no longer consider all of the 1990 recommendations necessary. [Feedback invited - CONTACT us.]

  • Piping shall comply with ASTM D 3309 (gray piping) Hot and Cold;
  • Stored PB piping may be loosely coiled or bundled but should not be taped
  • Use annealed copper crimp rings (note this may have changed since 1990)
  • Use copper or brass insert fittings
  • Compression fittings are permitted if of a type recommended for PB
  • Manifold connections (such as for radiant heating) must be of a type recommended for PB
  • PB piping should be free of cuts, gouges, or deep scratches, tar, kinks, grease, soldering flux, and should not be faded or discolored
  • PB piping end cuts should be square and free of burs (use an approved PB pipe cutting tool)
  • PB pipe crimp rings should be 1/8" to 1/4" from the end of the tubing and do not use multiple crimp rings at an individual fitting connection
  • PB Crimp rings shall be perpendicular to the centerline of the pipe or tubing (not askew)
  • Each PB crimp connection should be checked with a GO-NOGO gauge and any fitting that does not pass should be cut out and replaced.
  • In making a run of PB piping allow 1/8" of slack per 12" of run
  • The radius of a PB pipe bend should be 12 x the tubing diameter (or more).
  • Protective sleeves or bushings should be installed at the beginning and end of straight runs of PB piping when penetrating studs
  • Supports for PB piping shall be used at significant changes in direction
  • Horizontal support for PB piping should be 32" o.c. for pipes from 3/8" to 3/4" diameter, and at 48" o.c. for pipes from 1" to 1 1/2" in diameter.
  • Vertical pipes should be supported at every floor and at the mid-point between floors for pipes smaller than 1" in diameter
  • Piping supports should not restrict the horizontal movement of piping
  • With PB pipe use only hangers or supports recommended specifically for PB pipes
  • Do not connect a hose bib directly to PB piping. Use anchored metal pipe for this transition to avoid strain on the PB pipe
  • Transitions should be made with fittings approved for that use
  • Keep PB piping at least 6" horizontally and 12" vertically from high heat sources such as heating flues or heating pipes
  • Do not use PB piping in recirculating hot water plumbing loops; keep PB piping branch lines at least 36" off of recirculating hot water pipe loops; Hot water heater connections should be at least 18" away from the water heater (and separated by metal piping); do not install PB piping downstream from a demand-type or instant or "tankless" hot water heater.
  • Test pressure for PB piping systems should be at least equal to normal system working pressure but also must be not less than 40psi nor more than 225 psi. NOTE that some plastic piping is marked with other maximum pressure ratings that must be respected when testing too.
  • Pressure test piping for at least 15 minutes. Note that a light pressure drop in two hours is normal (due to slight expansion of the piping, not due to leaks).

PVC Piping: CPVC Chlorinated Polyvinyl Chloride Water Piping in buildings

Plastic sewer pipe installation (C) D FriedmanComplete details are at CPVC & PVC PLASTIC PIPING. Excerpts are below.

Chlorinated polyvinyl chloride (CPVC) pipe is not as flexible as PB or PEX and the fittings are solvent welded (glued) rather than press-on. This pipe is likely to split if freezing occurs. CPVC pipe is suitable for use on both hot and cold water lines.

Our photo (left) illustrates Royal brand PVC sewer piping being installed at a New York Home. Photo courtesy Galow Homes.

Watch out: PVC polyvinyl chloride pipe produced by JM Eagle Corp. is reported to be defective, leaking or breaking as early as in the first year after installation. Details are at PLASTIC PIPE LEAK CAUSES.

See WATER HEATER DEBRIS FLUSH for an example of a deteriorated plastic water heater dip tube debris that clogged the building water supply piping, faucets, fixtures.

Watch out: Using the wrong solvent adhesive, or not using it properly (including pre-cleaning the pipe joints) not only results in leaky plumbing, also the purple solvent cement makes permanent stains, as Oatey Plumbing points out:

The pigments or dyes in Oatey Purple Primer and Oatey Purple Primer/Cleaner are permanent. Depending on the type of material stained, its porosity and the length of time the stain has set, it may be possible to remove or lighten the stain.

We recommend blotting a clean, dry towel with Oatey Clear Cleaner to attempt to remove the stain. It may not be possible to remove the colorant from particular fabrics or surfaces. The finish and/or color of certain fabrics or materials may be dulled or discolored when in contact with solvents in Oatey Clear Cleaner.

You may want to try the cleaner on an inconspicuous spot before using on the stained area. Please use our purple primers and colored cements with caution.

PVC Pipe waiting for use (C) D Friedman

PVC is Poly(Vinyl) Chloride, CPVC is Chlorinated Poly(Vinyl) Chloride and ABS is Acrylonitrile-Butadiene-Styrene.

PVC and ABS pipe are normally used for drain, waste and vent (DWV) systems.

CPVC is used for water distribution systems. It is important to choose the correct solvent cement or pipe glue based on the type of plastic pipe being used.

Our photo (left) shows a close-up of markings on PVC sewer piping. Note that we took this picture of pipes resting on a gravel driveway.

You should not bury plastic sewer piping in sharp rocks but rather it should be bedded in sand and located 18" below the ground surface or deeper to reduce chances of damage from rocks or from vehicles passing overhead. Photo courtesy Galow Homes.


Complete details are at PLASTIC vs. COPPER PIPES in BUILDINGS. Excerpts are below.

Many plumbers prefer to work with copper and, although plastic pipe is less expensive than copper, the fittings are expensive. Some areas do not allow plastic pipes based on environmental concerns. Some questions have been raised about the chemicals used in the adhesives used to join sections of piping, and the toxic gases given off from plastic piping during a fire.

Polyethylene (PE) and polyvinyl chloride (PVC) are only suitable for waste, underground water service pipes or cold water piping systems.

Our photographs of plastic water supply piping connections show a new water main (below left) and building supply pipe being connected to copper piping entering a building (below right) in San Miguel de Allende, Guanajuato, Mexico in 2010.

Plastic water supply piping (C) Daniel Friedman Plastic water supply piping (C) Daniel Friedman

- Adapted with permission from Carson Dunlop Associates' The Home Reference Book

Reader Question: Do Rodents Attack Plastic Tubing or Piping? Does the tubing color make a difference in rodent resistance?

This might seem a strange question but we have blue plastic used for the connection from our gas tanks to our cooker. We have just had it serviced and have been advised that it should be yellow plastic. We have had the blue plastic for a lot of years and have been told it must be changed because the yellow tubing is not susceptible to vermin.

Since we have never had a problem with vermin and the blue tubing – I was wondering how true this is and why do the vermin not like the yellow tubing. It would be good to get some advice before we start doing unnecessary work. Thank you for your help - D.M.

Reply: Yes, No, and maybe

We have indeed had reports of rodents chewing on plastic piping of various types, colors, brands, and application (water piping and gas piping for example). And rodents will gnaw on other plastic piping too, not just PEX.

You didn't say exactly what kind of plastic piping you are using nor its brand - that information would let us check with the manufacturer for recommendations about rodent proofing the piping. Certainly we don't want a rodent-chewed hole in any piping but in gas piping it would be particularly dangerous.

I am doubtful that changing from one color piping to another would make much difference in rodent resistance if the piping brand and material is the same; but if the color change includes a change of material, the new material might be more rodent resistance.

In a New York installation I have seen yellow plastic-covered flexible copper tubing used for both gas piping (not through walls and ceilings or hidden locations) and heating oil piping. A mouse that chewed the outer plastic cover would most likely not get through the copper, but you'd lose the protective coating at that spot. At that same installation, we used threaded black pipe for gas piping where it runs through hidden locations such as ceilings and walls.

If your pipe damage is occurring indoors you need the services of a pest control expert - an "exterminator" too.

If you can send along details about the pipe type and brand we'll research further. See the CONTACT link on our pages.

Question: Pex vs. Copper Water Supply Piping - which should I use?

Question: my daughter is doing extensive renovations on her house and the question has come up whether to use PEX or copper in the plumbing. ... Any thoughts would be helpful. Thanks


PEX hot and cold water piping installed during new construction (C) Daniel Friedman Eric Galow 2012 2013Elisha I've moved this discussion to its own article found at


We will continue to monitor the PEX health and contamination question and will update here. CONTACT US by email to send field reports or to report on new studies.

Copper Water Supply Piping

The same PLASTIC vs. COPPER article above lists propertie of copper water supply pipes when used in buildings and compares copper pipe performance with that of plastic.

Each plumbing pipe material has its own vulnerabilities as well as advantages & disadvantages.

Copper Water Supply Piping

  • Copper piping is something that I personally love aesthetically
  • Copper supply piping is possibly familiar to more installers
  • Copper pipe fittings & connectors are less confusing than plastic - standard, old, known to old-timers
  • If all of the supply or drain piping in a building are continuous metal, then grounding the piping system increases electrical safety - a toaster dropped into a sink should blow a fuse or trip a breaker. This is a somewhat subtle safety point for which we have opinion, not data.

Copper Supply & Drain Piping Caveats

  • Copper piping too is at risk of leaks, even long-standing clandestine in-building-cavity leaks (when the leak is tiny) if each fitting is not installed properly
  • More than plastic water supply piping, copper piping is more vulnerable to leaks caused by aggressive water chemistry, or by an electrical ground mistake as well as leaks due to galvanic corrosion if piping is mixed with steel in an older home (unless you use proper dielectric fittings at those joints). Also
  • More easily than plastic water supply piping, copper pipes can be damaged by vibration (OPINION),
  • An amateur installation during copper fitting sweating (soldering) sometimes pushes too much copper into the joint leading to a very hard-to-find flow restriction.

We discuss types of copper piping and their intended uses and copper fittings beginning
at COPPER PIPING in buildings.

In sum, I don't believe there is a single "right" answer, and each material has some advantages and features that may make it fit a particular installation best. But when I ask my buddy Eric Galow, who is a full time builder, he's a PEX man all the way.

Question: is PEX the same as Kitec® ?

Is PEX the same as Kitec? How does one tell distinguish between Kitec and PEX? - Anon

Reply: Kitec was one brand of PEX piping or tubing.


PEX (cross-linked polyethylene piping) is a general term for a type of plastic piping used in water supply, heating, and other applications.

Kitec® is a specific brand of PEX tubing that was subject of a class action settlement with an end-date for filing claims of 31 March 2012. You can jump directly
to Kitek® plastic piping leaks, class action settlement; found within that article

There you'll see how to tell the difference between Kitec and other PEX piping brands by color and markings that may be on the tubing.

Details about PEX piping are



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