White PVC Drain Pipe Break (C) Daniel Friedman PB Pipe, Polybutylene Pipe in Buildings
Properties, uses, standards, defects, failure claims, class action

  • PB Polybutylene (PB) Pipes - CONTENTS: description of Polybutylene PB pipe use in buildings, installation, inspection, troubleshooting, leaks, failures, failure claims. PB Pipe Failure Claims.Recommendations (Specifications) for PB Polybutylene Water Pipe Installation
  • POST a QUESTION or READ FAQs about PB or polybutylene plastic piping in buildings: installation, inspection, cracks, failures, leaks, hazards
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PB polubutylene plastic plumbing pipes:

This article describes the properties of polubutylene (PB) plastic piping and tubing used in buildings.

We include information about failures and problems with some generations of plastic pipes (PB or polybutylene) and we describe good building practice installation details where plastic piping is being installed.

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 InspectApedia.com, All Rights Reserved.

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

Plastic drain piping (C) Daniel Friedman

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.

See Chlorine - sources in drinking water for related information.

Polybutylene water piping guidelines (C) Carson Dunlop Associates

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 right) shows hot and cold water piping using these materials and fittings in a new building.

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 are listed at REFERENCES
  • 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).


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PB Polybutylene (PB) Pipes at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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