Problems with your pipes? The poly pipes plumbing issue
Every era of housing has their strengths and weak points in terms of building materials and construction. For homes built in the late 1970′s and into the 1980′s, it is important to check the plumbing system. During this period, the first polybutylene plumbing was introduced. One of the brands that has been highlighted to be of major concern is Dux Qest (it is usually black (the black scourge one old builder called it when talking to me) and often has Dux Qest (or Quest) written in white along some of the pipe lengths). Some of this plumbing is now 25 years old and past the manufacturers expected lifetime as well as being well out of any warranty period. With Qest installed in more than 20,000 homes in NZ and millions worldwide, this will become an even bigger issue as time goes by.
After talking with a number of local plumbers, it is obvious that this pipework has been an issue for years and teamed up with the move from tongue and groove flooring towards the cheaper chipboard flooring products which swell and turn to mush when exposed to high moisture, can cause a bit of a headache for leak victims.
The tradesmen I talked to said that the leaks are caused either by the pipes splitting down the length or at the joints.
It may be more of a problem in homes with very high water pressure and leaks can exhibit after an old low pressure hot water cylinder has been replaced with a newer mains pressure cylinder lifting the water pressure dramatically in the hot water feed.
I’m told that the stress on the pipes can also be greater if the piping has been bent or curved around corners rather than using joints.
Another plumber said that the joints themselves are often the points that go first especially if they are under stress. The joints are secured to the piping lengths by crimped aluminium or copper rings. These rings can sometimes be over or under crimped and they expand and contract with heat and cold and may eventually split allowing the joints to come apart.
Something that I have seen personally, is a leak caused to poly piping by being gnawed by a rat! The rodent was obviously thirsty and bit a hole in the piping causing a small leak. A good reason to have a bait station in the underfloor and in the ceiling space of your home!
Some articles on the web have suggested that if the piping is exposed to lots of sunlight it can fail with the ideal being less than 30 days of sunlight exposure. But what if a coil of piping or a bucket of t-joints and elbows has been carted around on the back of a truck or been sitting in a plumbing van for months?
Other “experts” blame water with high clorination as the culprit which may explain higher failures in some areas of the country than other areas. Whatever the cause, the fact remains that this style of pipe work isn’t as good as old school copper plumbing.
Plumbing has come a long way even in the last twenty years, but most of the residential water piping I have seen being installed in new housing developments even this week is grey poly piping and after reading posts online from the United States I asked my plumbing contacts if these water pipes will also have issues down the track and they have said potentially yes, with some problems already showing up where the piping hasn’t been correctly installed to manufacturers specifications or short cuts have been taken or not enough care taken. Many plumbers have moved to brass joints with copper rings to hopefully avoid future issues. One brand of plumbing that was mentioned to me and thought to be worth consideration is Secura ( This isn’t an endorsement as I have very little experience with plumbing pipes and fittings, check it out for yourselves).
What does the Council or Government think about the issue?
I found the following press release relating to this plumbing (and I quote)
Tuesday, 19 April 2011, 8:59 am
Press Release: New Zealand Government
Dux Quest plumbing withdrawn 24 years ago“Dux Quest was withdrawn from the market about 24 years ago. It pre-dates the current Building Code and the Building Act,” Building and Construction Minister Maurice Williamson said.
“I am advised it was one of the first Polybutylene plumbing systems introduced into New Zealand in the early 1980s. When the piping was found to be problematic Dux Industries widely publicised the situation. They offered to replace the product for homeowners or pay for replacement material.”
In that era building consents were in the hands of borough councils, not the Government.
The Building Code; which includes plumbing and drainage; became fully effective on 1 January 1993. The Department of Building and Housing has powers to take action over products which result in buildings failing to comply with the New Zealand Building Code. The New Zealand Building Code is not retrospective.
“Issues with Dux Quest plumbing have never been raised with me in my two and a half years as Building and Construction Minister,” Mr Williamson said.
Mr Williamson said people concerned their home or business may contain Dux Quest plumbing should contact a certified plumber for an inspection. “
Your plumbing can affect your sale price

Obviously, the powers that be haven’t yet come to the full realisation that this is a serious issue for 1980′s homeowners and may become an issue in the future for the owners of modern day homes.
At the house buying and selling coalface, however, the Quest issue comes up regularly in 1970′s and 1980′s homes when purchasers have building inspections conducted on their behalf. Any Quest plumbing will normally be highlighted in the building report as substandard and more often than not, the buyers, if they are not scared off purchasing the property at that point, will come back to the owners to renegotiate the price to reflect the remedial replacement work that will have to take place to make sure the plumbing doesn’t have problems.
Insurance Issues
What many homeowners don’t realise is that many insurance companies won’t payout if this problematic plumbing leaks and causes damage. If you are lucky, you may get paid out once for damage but after this point, you are considered to have been made aware of the problem and no further payouts will happen if you don’t get the plumbing attended to and further damage takes place.
What can you do if you own a house with Dux Qest (Quest) plumbing?
- Have your plumbing checked by a qualified tradesman asap. There may be small leaks or areas of stress that are easy and cheap to fix which could cost thousands of dollars of damage if left.
- If you have a mains pressure hot water cylinder, have pressure limiting valves installed on the hot to keep the pressure from being too great and stressing the pipework.
- Turn off your water at the toby when you go away on holiday. An easy safeguard that could save you a rather stressful post holiday problem. I heard of one house where the pipes burst in the wall of an upstairs bathroom and water was pouring through the upper story of the house for three days. You can only imagine the amount of damage that took place.
- Look at replacing your hot water piping at the very least, if not all of the plumbing. This can be done when you upgrade bathrooms, kitchens and laundries. It may not be as expensive as you think.
- Have plumbing installed under the floor or in roof cavities that are easy to access rather than in walls if possible.
- Check your insurance policy – look for sentences like “ongoing or gradual water damage” which usually applies to leaky building type issues but may be used as an opt out by the insurance companies if your pipes spring a slow leak.
- If building a new home, pay the money and have copper piping installed especially on the hot feed.
- Make sure the plumbing is installed by an experienced and qualified company to the manufacturers specifications.
If you are buying a 1980′s home
- Make sure you get a builders report by someone who knows what they are doing and who is comprehensive in their approach. Moisture meter testing can pick up potential leaks behind walls that may not yet be obvious to the eye.
- Ask the agent or get them to ask the owner if there has been any problems to date with the plumbing.
- Be aware that this is a potential issue with homes built in the 1980′s. It shouldn’t necessarily stop you from purchasing a home of this era, but forwarned is forarmed. Be aware that you may need to spend some money down the track maintaining or replacing this pipework and reflect this in the price you offer to the buy the house for but be realistic, don’t play silly buggars and try to have $20k wiped off the price, most owners would tell you to get on your bike and you’ll miss out on buying your dream home. Get a realistic quote from a plumber and use this as evidence in renegotiations if you are going to follow this route.
- Make sure the building inspector checks the plumbing in more than one place in the house, often homes will have a mixture of old and new plumbing reflecting either fixes to past problems or renovations to amenity rooms.
My website www.northernsuburbs.co.nz
August 22 2011 01:11 pm | General Real Estate
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