PNW Investigation PEX F1960

Pacific Northwest Place Condominium
Review of the Uponor F1960 plumbing system:

Note: Due to the litigious nature of this issue, any building rendering or names of participants mentioned in this report are fictitious where applicable.  This is an educational document that provides a case study for investigating a PEX system for a single client in thePacific Northwest. The client was receiving conflicting information from litigators and other “experts”.  Coengineers was called to help stop the spin.  This is not meant to represent professional engineering decisions or recommended course of action. 

 Executive Summary:

Litigation is pending against Uponor, the manufacturer of PEX domestic water pipe systems compliant with ASTM F1960. However, there are strong conflicting opinions in the engineering community whether there is a widespread problem with PEX reliability or not. It is neither likely that these technical conflicts will settle easily nor could they be resolved at a reasonable cost by a single condominium association. As such, widespread extraction and sampling would have little practical value.

From an external inspection, it does not appear that the Pacific Northwest Place Condominium Association currently has a problem with their domestic water system matching the claims against Uponor F1960. Still, it is prudent to understand any issues that may or may not arise during the service life of any critical system. The warranty period from the original builder, plumber, and water system manufacturer is still in force for at least one more year. This time should be used wisely.

  1. Pacific Northwest Place Condominium should call upon the builder and the plumber to verify the design and positively identify the components of their plumbing system.
  1. Pacific Northwest Place Condominium should perform a simple and limited extraction of an exposed brass fitting to determine manufacturer, foundry, and metallurgical composition: is this yellow brass or not?
  1. Pacific Northwest Place Condominium should form an information sharing community with other local condominiums to share information on brass composition, leak events, leak detection, leak locations, and cost of repair.
  1. Pacific Northwest Place Condominium should include moisture testing in their maintenance plan.
  1. Pacific Northwest Place Condominium should increase reserve funds for a re-fitting/re-pipe at year 20-25 instead of year 30-40. Funds from this account may be drawn down to repair any leaks if they happen.

Class action, or any litigation, can be a lengthy, invasive, and expensive proposition with no guarantee of success or assurance that any award will cover the cost of effort and remediation. On the contrary, it would not be wise to exclude the association from the possibility of legal action if the condition turns out to be problematic at any time in the future.

The report prescribes a strategy for managing risks associated with claimed reliability issues while also not committing the association to any severe actions without probable cause cause.

PNW Investigation PEX F1960 Introduction:

Pacific Northwest Place Condominium Association retained Community Engineering Services, PLLC, in response to concerns that other condominium communities of similar year and style were performing investigations on their plumbing systems based on recommendations of a forensic engineering firm and legal counsel.

A recent rash of lawsuits in Nevada and Colorado have been argued over failures in some brass fittings due a corrosion process known as dezincification. In short, brass is an alloy of copper and zinc. There are many factors involved, but if some of the zinc dissolves from the alloy, the remaining copper could become porous and weak resulting in chronic leaking, or in the worst cases, catastrophic failure.

On the other hand, millions of installations have served trouble free over the 20+ years since PEX has been introduced to the plumbing trades in the US. These installations are expected to serve reliably for their entire expected service life of approximately 40 years. As such, the Pacific Northwest Place Condominium seeks to understand and mitigate risks, if any, associated with brass components in their plumbing system.

Since there does not appear to be any current leakages, Community Engineering Services, PLLC will treat this as a risk management problem and not a scientific determination on brass corrosion.  In order to manage risk, three questions must be answered absolutely no matter how tempting it may be to jump to a convenient or appealing conclusion.

  1. Can we identify the risk exposure?
  2. What is the probability that the peril will impact us?
  3. If it does, what are the consequences?

This study will seek to answer these questions about the PNW Place domestic water system.

What Is a PEX water system?

PEX stands for high cross-linked polyethylene. Polyethylene is a very common material used in many products such as children’s playground equipment, kayaks, piping, and plastic sheeting. Polyethylene is a polymer. Where a ‘mer’ is a single string of plastic, a polymer would refer to a grouping of mers. Cross-linking is akin to a tangled group of strings of mers. The cross-linking gives the polyethylene its characteristics to strongly seek and retain original shape, bend without buckling, and carry pressure in a wide range of temperatures. PEX is truly a remarkable material.

PEX often comes in long lengths of rolled tubes. Lengths of PEX are connected or branched off using fittings that are made of brass or Engineered Plastic (EP). PEX tube can also connect to other materials such as copper lines serving water heaters, showers, and sinks, etc. We will refer to these as PEX-to-Copper transitions that may include a brass fitting.

The Uponor System is a very popular manufacturer of PEX systems for homes. The Uponor fitting system is also referred to as ASTM F1960 system because the American Society of Testing and Materials has established a standard that specifies materials and geometry of this specific PEX system. Codes and standards are developed for the purpose of safeguarding the public.

EP manifold

Typical EP Manifold

In order to install PEX tube, a special tool slowly spreads the PEX and a reinforcement ring. Before the PEX can return to it’s original size, the PEX is slipped over a plastic, copper, or brass barbed fitting. Due to the cross linking characteristics of PEX, it will seek it’s original size in a few moments after stretching and will squeeze around the barb creating a water tight seal.

The F1960 system has been installed in millions of homes across the country since being introduced in 1992. Recently, there have been reports of leakage and some failures in some southern states resulting in lawsuits. The phenomenon has been studied extensively in the scientific community. Some possible causes may include water chemistry, brass chemistry, Temperature, Velocity, etc. Updates are referred to the ASTM board for revision to the F1960 standard, if needed.


Typical copper stub out with Uponor fitting

It is important to note that not all of these systems are failing and it is the task of the Pacific Northwest Place Condominium association to understand the water system that is installed in their community and manage any risk that may be present.

Process Summary:

As with any indeterminate condition, rumors and conjecture can run rampant in a community.  An effective solution should be simple, yet comprehensive to include as many possibilities as possible. For this reason, Community Engineering investigated a very wide range of circumstances.

The following steps were performed in support of this investigation of the Pacific Northwest Place Condominium Association PEX Piping system:

  • Review of the PNW Place Condominium available plumbing documentation.
  • Site visit to review and photograph 3 separate units.
  • Reviewed class action claims and challenges
  • Reviewed insurance policy related to plumbing.
  • Published an extraction plan statement of work.
  • Compiled all information on a private webpage.

In addition, we conducted interviews with the following:

  1. stub angle

    Typical stub-out with Uponor barbed fitting

    Delux Homes, the builder

  2. Maxflow Plumbing, the contractor
  3. HOA board member
  4. 4 current residents residents,
  5. Group Survey of all residents.
  6. Current property managers
  7. Uponor manufacturers representative
  8. At least 4 professional engineers familiar with claims
  9. Legal council retained by Pacific Northwest Place Condominium

Construction Drawings:

As-built drawings were acquired at the PNW City permit office.   The plumbing design was expressed in a hand drawn sketch identifying general layout and pipendiameter sizes. All other specifications pertaining to a PEX system is covered in the city codes, including appropriate ASTM standards for PEX systems and materials. ASTM F1960 standardizes this PEX system. UNS C36000, C37700 Brass composition, defines high zinc brass. UNS C31400, 89844, 84400 defines low zinc brass.

The Builders

We spoke with Staff at Delux Homes’ community liaison and first point of contact for communities seeking information about their homes. Delux Homes was unable to provide as-built drawings or architectural specifications for the Pacific Northwest Place Condominium. Eventually, the architect granted permission and the filed drawings were obtained. In any case, it is advisable for a community to possess a copy of the design drawings that represent their homes.

Delux Homes was also able to provide the name of the plumber who was contracted to pipe this specific project. Maxflow Plumbing; of PNW City is a licensed commercial plumbing contractor.

 The Plumber

Maxflow Plumbing is a reputable commercial plumbing contractor with a longstanding relationship with Delux Homes. On-line resources showed pictures of several Maxflow installations that were consistent in methods to what was observed at the Pacific Northwest Place Condominium – generally appearing to be neat and clean installations. Maxflow Plumbing verified that they have been using engineered plastic (EP) almost exclusively for many years and that if they started the job in EP, there was a high probability that EP was used throughout the project.

The plumber also verified that they only procure parts from the manufacturer or reputable suppliers and manufacturer representatives. They were unable to offer design specifics such as manifold location (if any) without further review of the property.

Manufacturers Representative

The Uponor manufacturers representative provided specific information related to the manufacturers warranty that covers any product defect. In short, if the failure occurs within 10 years of installation, Uponor will pay for damage created by the failure in addition to replacing the affected components. If the failure occurs after 10 years and before 25 years, Uponor only covers cost of replacement of the failed component.   The Manufacturers representative for this product is Hollabaugh Brothers and Associates (503-238-0313; Logan Williams provided a copy of the Uponor extended warrantee applicable at the time that the PNW Place Condo was built

Legal Counsel

Interview with legal counsel retained by Pacific Northwest Place Condominium resulted in copies of the engineering report initiating the class action lawsuit authored by PNW Engineering Inc. The PNW Engineering Inc. report provided their detailed analysis, photographs, as well as a variety of claims against the material, the design, and the installation of Uponor ASTM F1960 systems. The class action filed has not yet certified as of this writing. There is little indication of the likelihood of success for the legal action.

We also found additional resources such as sample presentations by various law offices made to HOA boards urging them to review of components on the basis of claims made by engineering consultants and initiate a suit. Some lawyers advise communities not to wait for leaks because it may then be too late to make a claim. Others suggestion that included filing a solo suit instead of a class action could result in a greater award.


We reviewed the insurance policy related to the plumbing system. Pacific Northwest Place Condominium would more likely be covered for a sudden and accidental breach of the water system and related damage. Otherwise, the Pacific Northwest Place Condominium is not likely covered for slow dripping or seepage that causes damage if that leak had been active for more than 14 days.  The policy is explicit in that corrosion is not covered regardless of the insured’s ability to observe it.

There is a low probability that a slow leak behind a wall could be discovered in less than 14 days. Likewise, if a leak is discovered, there may not be an easy way to prove that the slow leak started within 14 days of discovery. For these reasons, insurance would probably not be a good mitigation tool to rely upon.

Keep in mind that insurance companies benefit from years of experience and huge data sets over extended periods of time, which helps them to limit their liabilities. History with galvanized pipe, copper pipe, CPVC and other materials have been leaking long before PEX arrived.

Pacific Northwest Place Condominium Resident survey

We conducted a simple 3-question YES/NO on-line survey of the 121 households in the Pacific Northwest Place Condominium. The survey asked the following questions:

  1. Have you ever had a problem that required the services of a plumber? 
  1. Have you ever encountered a leak from your water system pipes? This would appear as continuous wet or soaked wallboard, ceilings, or staining on molding or flooring. This does not include leakage associated with overflow/splashing from shower or toilet or sink, etc. 
  1. Have you ever heard disruptive knocking sounds from within the walls when the water is turned on, or shut off, at any fixture (i.e., bath, sink, washer/dishwasher)?

The response rate was approximately 50%, and none had discovered any leaking, wet walls, or staining attributable to a fitting leaking within a wall. While the survey is not conclusive, the response rate is significant and any leaking that may exist, is currently not obvious to the residents.

Moisture meter

Moisture Meter may help locate leaking in prone areas

 Engineering Disagreement:

This discussion is by far the most contentious part of this investigation. We spoke with 4 professional engineers from 4 different forensic firms related to a variety of factors concerning this investigation. There are two hard and clear sides to the engineering argument concerning dezincification of brass fittings in the Pacific Northwest.

One side, we’ll call “Side A”, is convinced that the Uponor F1960 system is a big problem and should be replaced. “Side B” is convinced that Uponor F1960 system is not a problem and should not need to be replaced. Engineers from both sides of the discussion are highly qualified with many years of experienced and advanced degrees in metallurgy from prestigious educational institutions. They have been opposing each other for almost a decade on every aspect down to the level of atomic structures.

Both sides are equally qualified and equally biased to their respective views. Side A claims that Side B is paid off by wealthy corporate interests to argue for the defensive position. Likewise, Side B claims that Side A enjoys a lucrative business in litigation, testing, scoping, and re-piping buildings that are deemed fragile by none other than Side A.

It can only be determined that both sides are equally biased.

We will not dive into every scientific argument and counter argument in this dispute. We can only observe that there is no consensus as to the cause, likelihood, or consequences of these failed systems. Peer-reviewed professional journals and citations most often resolve these matters. Obviously, this has not occurred. The default position is to fall back on ASTM standards and existing plumbing code compliance.

Side A makes the following claims:

  • All yellow brass dissolves in all water chemistry and that no yellow brass should ever be used in contact with water because they will all fail.
  • The shape of the Uponor fitting barb is faulty and all such fittings must be replaced with an unspecified new design.
  • Tooling marks created at installation provide a leak path for water and therefore the installation is inherently vulnerable to workmanship issues.
  • Products of corrosion stick to PEX and break the watertight seal with the fitting.
  • Tube stresses in bending produce excess stress concentrations in the barb fitting exceeding the strength for a fully de-zincified fitting.
  • Dezincification periodically releases grains of lead into the water.
  • A full re-pipe is required and all PEX systems must be converted to copper.

Side B has been able to contest each claim from Side A with a technically robust counter claim.  While it is easy to determine if a system contains yellow brass, it is not easy to determine the likelihood that the brass has or will fail by dezincification, or any other claimed peril, without performing extensive and invasive extractions of a statistically representative and controlled sample from the entire community of homes. It would be prohibitively expensive for Pacific Northwest Place Condominium to respond independently to each of these claims.

The cost of performing a proper test may run between $20,000-$50,000 dollars including extraction, lab tests of 20-30 samples, and wall restoration to a quality finish. The benefit of doing so would be questionable for the following reasons:

  • If a leak is found by invasive wall removal of nearly all locations, it would not likely be covered by insurance and a water damage disclosure would be required at the time of selling a resident’s property.
  • If a resident is vigilant and observes the leak independently, the damage would be comparable to an extraction, it would likely not be insured, would also require a disclosure at the sale of their unit. So there is little difference between the two outcomes as long as proper maintenance is performed.
  • One condo extraction cannot settle the whole technical issue, which may be needed to sway a jury or arbitrator.
  • According to the claims made by Side A, if a large extraction is performed, it is almost certain to uncover some dezincification or corrosion somewhere, or some deficiency in the Uponor design, even if no fitting has yet failed. The recommendation would almost certainly be to re-pipe costing between $5,000-$15,000 dollars per unit.

As such, there is little reason to perform an extensive extraction if the outcome, given yellow brass, is certainly going to be a re-pipe. Therefore, the $20,000-$50,000 dollars are best saved for a re-pipe if the system begins to fail or upon the end of the service life.      

Leading Assumptions:

  • It is more likely than not that the plumber used engineered plastic fittings on all PEX-to-PEX transitions and manifold. Pacific Northwest Place Condominium should ask the developer to verify and define installation via warranty claim.
  • It is likely that the copper stub-outs that pass through the walls to serve the various fixtures would have a brass fitting transition from PEX to Copper.
  • It is also more likely than not that the formulation of brass used in any part of the system is near identical to the formulation of any other part of the system.

Therefore, a likely scope of repair would be to replace the copper stub-outs at the fixtures with low zinc brass fittings rather than perform a conversion to another piping material. 

Site Visit:

A site visit was conducted of three separate units from two construction phases.

TB Survey 2b

An exposed section of PEX pipe was found at the location where the water service enters the unit. It passes through a pressure regulator and a main gate valve, and then splits off to the hot water supply line and the cold-water supply line – both behind a wall (Figure 3).

Figure 5 demonstrates minor corrosion at the solder joint and less on the Uponor PEX fitting. Figure 6: shows some mild corrosion on copper components suggesting that corrosion is not isolated to brass fittings nor would a copper re-pipe be without it’s own corrosion issues.

Figure 7

demonstrates typical assembly that we would expect to be consistent throughout the facility. It is observed that the plumber used engineered plastic (EP) fittings for PEX-to-PEX connections such as elbows, tees, and unions.

Construction Defect: In two out of the three units observed, there was an installation of a threaded union containing iron such as galvanized steel, which was actively corroding. While we would like to assume that all transitions behind the walls are exactly as those in from of the wall, the presence of the odd steel fitting casts doubt on that assumption.

Figure 8: Shows active corrosion of iron in a predominantly copper system without isolation from galvanic reaction. It is not known if this corrosion will impact the valve thread ability to seal water.

The steel union must be replaced under warrantee with the builder. Any damage incurred upon the flow restrictor preventer and the gate valve must also be remedied under warranty.

Fig 6 minor corrosion

Figure 6


Observed Corrosion Summary:

We are able to visually verify some corrosion in brass at the transition from PEX to the brass valve at the solder connection, not the PEX connection. We were also able to see corrosion at copper fittings at the hot water heater. Additionally, corrosion is seen at a steel union between two brass valves. None of these are likely due to the claims for widespread dezincification specified in the legal action. Further, Corrosion in copper and steel demonstrates the vulnerability to corrosion for common alternate plumbing materials cautioning the owner not to trade one problem for another.

Extraction Strategy:

There was an exposed Uponor barbed fitting and ASTM F1960 connection at each side of the gate valve in the cold water service line. Since the legal action claims are

EP Tee elbow

Figure 7

against all yellow brass fittings, this test item will constitute our initial claim for admission to the class actions against the builder, plumber, and manufacturer, if applicable.


We recommend obtaining an RFI (request for Information) from an engineering firm from Side A to specify the test protocol for the composition of the brass fitting so we may correlate our sample with the inventory of failure claims. The result of the RFI will go to RFP for selecting the lab from either Side A or Side B to perform our analysis.

We also recommend requesting Side A and/or Side B to review test results to provide a statement of probability for if, when, and where this system will fail and what parts are most likely to fail in a typical installation given a particular brass composition. Then, we should ask that they suggest remediating actions that must be taken to detect leaks and maintain the system, if applicable.

These statements may then be presented to the developer for remediation under warranty claim or to the manufacturer to pay for additional investigation within the warranty period. Retained counsel may also use these statements to qualify P

Figure 8

Figure 8

acific Northwest Place Condominium for class action participation at a later date, if applicable.

If Red Brass is found, which is not vulnerable to dezincification, then further tests should be done at the expense of the Pacific Northwest Place Condominium to determine the certainty that the whole system is also Red Brass.

Planning for the future:

Side B of the engineering opinion claims that there is no problem with the brass fittings and the Uponor design. They claim that the system will achieve 40 years of reliable service as designed. Millions of households have reliable PEX systems over 25 years old. Our recommendation, as for any critical system, is to be vigilant of leaks in the plumbing material and perform all recommended maintenance, but not be frightened into performing a complete re-pipe that may not be needed.

For Pacific Northwest Place Condominium, we have established that the PEX-to-PEX transitions are not vulnerable to corrosion and that only the transition to the stub-outs would have a problem if any problem exists.

Therefore, the mitigation of risk may be limited to replacement of specific fittings rather than the entire system

Side A has not claimed any specific fittings that are most vulnerable to failure in the immediate future. While they identify many factors that may lead to failure, they do not specify where those factors are most likely to conspire to create a failure. Side A has not specified probabilities of failure under specific circumstances except that all fittings are vulnerable. Due to the nature of confidentiality in legal proceedings, the condominium communities have limited access to data, which would allow them make important maintenance decisions on their own.

It is recommended that condominium communities with a water district or neighboring water districts, share information between themselves about leaks, repairs, and costs. Their respective legal counsel may facilitate this.

Re-piping vs. Re-fitting:

A re-pipe generally refers to a complete replacement of an existing plumbing system with a new plumbing system. Old components may be removed or simply abandoned in place. Many re-pipes include conversion to a different plumbing material. All valves, pumps (if any), and individual fixture service are also replaced. Extraction usually involves opening walls, passing through studs, and subsequent repair of those walls to a quality consistent with the overall quality of the property.

A re-fitting can be simply considered a partial replacement. Re-fitting would likely fall into a class of repair as a custom renovation or restoration and is therefore unique to the clients specific problem and configuration. A re-fitting would be performed to a limited scope of work and may include more change orders as unique circumstances are encountered. The re-fitting may also have a warranty that is limited to that scope of work.

While it would be easy to approach any plumber and ask for a re-pipe for a quote, it may be more difficult to price a re-fitting because such a product is less familiar in the market.

In the case of Pacific Northwest Place Condominium, refitting may be an option because engineered plastic is used in the fittings that are widely distributed behind walls. The afflicted fittings, if any, would be limited to the stub outs where the PEX transitions to the copper that passes through the wall at the fixtures.

The stub-out location would be partially hidden behind a wall and close to each fixture. Areas under sinks, behind walls, and appliances would be hidden from view and may be restored with an access panel instead of new wallboard.   Other areas such as a hidden manifold or mixer valve may also be restored with an access panel to facilitate future inspection.

Replacement Funds:

Most reserve studies will not specifically fund systems that are expected to last more than 30 years from the time of the study. Many PEX systems may not currently have reserve funding for accelerated water system maintenance, repair, and replacement. The reality is that there is little consensus among engineering opinions, the relevant standards (ASTM) are in compliance, municipal codes are in compliance, and litigation is slowly wandering through the legal system. It seems prudent for any community to fund for maintenance, repair and replacement with vigilance and intention.

While a design life of 20-25 years instead of 40 years may seem arbitrary, it does put the water system within the reserve study funding range. It will increase the visibility of any such problem to the board and it’s members and it will provide a place to capture data regarding system performance. Finally, it would help condominiums share among themselves any information that they gather related to their system performance.

Summary Conclusion:

The logic leading to this conclusion is based on many factors. This summary conclusion will review those factors and clarify recommendations:

No Consensus in engineering community

  • Both opinions are equally valid
  • Both sides equally biased
  • The default position is stated in ASTM standards and plumbing codes

Side A Claim is too broad and unmanageable:

  • All Yellow Brass will fail
  • All Uponor Designs are Faulty
  • All systems must be replaced
  • No provision for limited mitigation


  • Plastic fittings are not vulnerable to corrosion
  • Visible brass is not showing signs of dezincification
  • No leaks have been observed by residents

Warranties are still in place:

  • One year remaining on builder’s Warranty
  • One year remaining on Uponor extended damage warranty
  • Sixteen years remaining on Uponor part replacement warranty
  • Insurance does not cover slow leaks left over 14 days

Reserve Funding: 

  • Update Reserve fund in case there are leaks, if they happen
  • Update Reserve funds for limited re-fitting, if needed
  • Update reserve funds for future re-fitting, if needed

Invasive extraction is not a recommendation:

  • A representative sampling and analysis would cost $20,000-$50,000
  • Full extraction is of questionable utility
  • Association should prove only the fact of “Yellow Brass” or not
  • Estimate the probability that the class action will be successful.
  • Estimate the cost of participating in the class action.
  • Estimate the benefit should the class action be successful.
  • Seek extractions under warranty.

Manage risk:

  • Identify all components for corrosion hazard
  • Perform moisture tests in community maintenance plan
  • Be prepared to join suit if necessary

Next Steps:

  • Conduct system definition under warranty
  • Replace iron corrosion under warranty
  • Establish roles and responsibilities for extraction w/Counsel
  • Solicit RFI from PNW Engineering for analysis
  • Solicit RFP from plumbers for re-fitting
  • Update reserve study
  • Implement moisture tests with CMI/Maintenance plan.