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Copper water pipe verse plastic pipe # blog 6

I have long been conflicted has an Aussie plumber about which product is better to use in certain situations. I have my own personal preferences, but during this article I am going to judge each pipe material by a specific set of criteria, at the end of each section I will judge the winner and hopefully by the end we will have an overall winner.

It is important to note that I have worked for most of my career when Plastic pipe has been the dominant pipe work, and I have a preference before writing this article for plastic pipe. Will this article change my mind? I believe that plastic pipe will just win.

Let’s start with the obvious criteria first;

Pipework Characteristics

Plastic water pipe or “pex pipe” is part of the cross linked polyethylene family and is used to supply water services in Australia, the US and Europe.

Pex pipe comes in many different colours, which is brilliant if you are a plumber at installation stage of a home because in certain shires there are additional requirements to install hot water, cold water, tempered water, rain water, and recycled water. It can become very easy to cross connect services and different colours definitely lower the chances of this happening.

The different colour also help you ID not only the water type in the pipe but also the brand of pipe, which really helps with future maintenance.

Copper pipe does not come in different colours but it is offered in different forms for example annealed, lagged,straight lengths, or rolled. I feel like this variety offered helps copper step above pex in this category.

Winner Copper ⭐️⭐️⭐️⭐️⭐️

Pipework Flexibility

Plastic pipe usually comes in 50/100m rolls which make it easy to transport and 2 rolls will usually complete a whole job. The flexibility of the pex pipe mean it is great to work with, easy to pull through long pipe runs and work in tight spaces. Pex pipe is also good when it comes to having to divert around obstacles. Copper on the other hand comes mainly in straight lengths with the coiled annealed copper too expensive to make it s real choice for installation. Copper certainty keeps its shape better than pex and is easier to keep neat and straight but pex pipes flexibility makes it far faster to install and repair. Copper can be bent at sharp angles but the time cost eliminates this advantage.

Winner – Pex ⭐️⭐️⭐️⭐️⭐️

Heat Resistance

Pex pipe is considered very good when we consider heat loss from hot water travelled through the pipes, with only small losses, making it environmentally friendly and energy efficient. Copper on the other hand as high heat transfer and loss. In colder climates this is a big factor but in sunny Queensland most pipework is run in insulated ceilings space where losses are minimal.

Copper can also be used with much higher water temperatures. Where pex is prohibited, copper is able to withstand the heat associated with the Solar hot water system, storage hot water system connections, and pipework which is heat and uv exposed to the sun.

Winner Copper ⭐️⭐️⭐️⭐️⭐️


The pex system is a quiet system and virtually eliminates water hammer and rattling. This is a lot to do with the noise conductivity of pex and it really helps that pex is flexible and allows for long radius bends this creating less internal friction and helping reduce the impact of shock waves from coding valves.

When we think of old copper pipework we think of water hammer and rattling pipes and even though standards have improved and technological advances help, copper still cannot complete with the silence of pex.

Winner Pex ⭐️⭐️⭐️⭐️⭐️


Pex has a larger out side diameter and small internal diameter as a rule which means copper general allows for greater water flow for the same size comparison as pex and even though pex does offer more in id sizes though the size range, the major factor still remains, copper is smaller and provides more volume of water.

Winner Copper ⭐️⭐️⭐️⭐️⭐️

Environmentally Friendly

At the end of the pex system life cycle it will be replaced with another piping system and the old pex thrown away, with only the brass fittings recyclable. On the other hand we have copper which is 100% recyclable and I can tel you from first hand that we as plumbers don’t usually throw copper because we keep it for scrap to get extra cash, whereas I always through pex off cuts!!

Winner Copper ⭐️⭐️⭐️⭐️⭐️

Impervious Nature of Materials

Copper and pex are both pretty impervious otherwise they wouldn’t be used for water pipe. The reason I bring this criteria into play is because plastic pipe has been known to allow termite chemicals to permeate the water supply when installed close to the house boundary, in areas where the termite chemical is sprayed. It is in the processes now that the new rules will be that the last 1-2 meters leading to the house will have to be copper, plastic pipe will be prohibited. Knowing this information most plumbers should start using this practice anyway. I will pass on the update when it is issued.

Winner Copper ⭐️⭐️⭐️⭐️⭐️

Pipework Fittings

Pex pipe fittings are dominated by brass fittings which are heavy and are prone to chemical attack, this being said I have only ever pulled one corroded fitting out in 11 years and this was due to poor installation. Pex also comes with a great variety of transition fittings to help the transition from pex to copper, pex to pex and copper to copper!

Pex pipework systems are slowly but surely changing their brass fitting system over to pex fittings too, they are less environmentally friendly but are lighter, cheaper, have less chance of corroding and are helping make our water more ph friendly.

Pex fittings also come in different forms, for examples there are climp type, push fit type and threaded type, all add to the ease of installation.

Copper fittings are basically all copper which helps with the corrosive factor caused by using different metals together. Copper does however also come in a variety of types from crimp to welded to threaded, copper catered for all transition fittings and methods of joining.

Both pex and copper offer great versatility with fittings but ease of installation helps pex normally win this one.

Winner Pex ⭐️⭐️⭐️⭐️⭐️

Warranty Periods

The pex piping system had been used in Europe for the best part of 50 years and is still going strong.

Taking this into account, Australian manufacturers offer you a 20-25 year warranty on their pex products, so you can be assured that if the pipework is installed correctly and used as intended, it will comfortably last its warranty period.

Copper manufacturers are so confident that their products are superior that they provide a 50 year warranty on their products. Some wholesalers only pass on a 25 year warranty period, but this is still as long as any pex product I could find.

Winner Copper ⭐️⭐️⭐️⭐️⭐️


I would say quite easily the biggest reason why most plumbers use pex systems are the cheaper cost factors.

Pex is firstly a lot cheaper to purchase off the shelf but where the big saving comes is with installation time. For example where a house used to take two plumbers one day to plumb in the water pipes, it now takes one plumber the same time to do the job, saving huge amounts of time and allowing plumbers more time to take on more work.

Copper has made advances with installation efficiency by the inclusion of the climp style fitting, but these are so expensive that they are only really cost effective when pricing against copper welding.

You could argue that copper has a longer working life but with 50 years of pex use in Europe this factor becomes a little less important.

Winner Pex ⭐️⭐️⭐️⭐️⭐️

Safety factors

The pex piping system has one massive safety advantage for me and that is it doesn’t have the same high electricity conductivity ratings. Electrical technicians can no longer use pex plumbing to earth their wiring. It is still a major thought in my mind and when I go to an old house to repair some pipework that, the house plumbing may be carrying electrical current.

Pex crimping tools do present a pinch points which do hurt if you get caught but nothing major from experience.

Copper pipework presents more installation dangers with hot welding presenting potential fire risks to the home or burns to the plumber, not to really mention fumes from the welding.

There is a clear winner here.

Winner Pex ⭐️⭐️⭐️⭐️⭐️

Water Quality

Pex pipework are made up of lots of chemicals and if left for periods have been known leach these chemicals into the water. I have experienced this first hand, but only on one occasion and with a brand of pipe I had never used before. My advice is to buy a brand which has stood the test of time and this problem should not occur.

Copper does provide lovely clean water but also had some problems. Scaling over time and poor copper imports are helping detract from the quality that copper has provided in the past. This coupled with the huge technological improvements in pex quality means there is only one winner over the product life time.

Winner Pex ⭐️⭐️⭐️⭐️⭐️

Pipework sizing

Pex pipework is pretty limited on size variety but this is ok has we usually do not need pex to be any lager than 32mm for commercial or domestic water. The problem is that most suppliers don’t really stock pex above 20mm, so anything larger than this needs to be ordered in advance.

Copper on the other hand usually ranges from 6mm to 200mm and even larger and is widely available from most stores. You could probably probably walk into a Reece store tomorrow and pick up 100mm copper and fittings off the shelf with no problems.

Winner Copper ⭐️⭐️⭐️⭐️⭐️

Location uses

Pex piping is mainly used in consealed locations and can be buried under ground or below a concrete slab with proper protection. Pex pipe can not be used in direct sunlight as it is easily damaged by uv rays from the sun.

Copper can also be used in the same places as pex, in addition though copper can be used in direct sun light and is the product of choice for areas where water pipework is exposed due to its nice straight finish and hard shell.

Copper is susceptible to the elements, water driven corrosion and freezing but thermal lagging and good work practices help copper through these weak areas.

Winner Copper ⭐️⭐️⭐️⭐️⭐️


Copper and pex are both commonly used in water, gas and air installations, copper is also being used in commercial drainage and fire. The uv resistance and hard shell of Copper gives it uses in areas where pex is just not viable.

Winner Copper ⭐️⭐️⭐️⭐️⭐️


When we talk about pex and it’s associated maintenance issues, a lot of these problems occur from defective installation, for example, pipe rubbing on metal surfaces causing a leak, scratches on pipe at fitting connection causing a leak, uv damaged pipe are the main culprits. You do hear about rats and mice chewing through pipes but I am yet to see this first hand.

Copper to me is the most problematic when it comes to maintenance. Corrosion from the lime in the concrete, dissimilar metals are a constant source of leaks in the plumbing industry. Old hot water units used to have their tanks made from copper but have nearly all changed to the more reliable stainless steel because the ever decreasing shelf life of the copper tanks.

Winner Pex ⭐️⭐️⭐️⭐️⭐️


The results are in and the winner is copper with 9 wins compared to the pex systems 7 wins.

I did not think that copper would win but having spent the time to go through each section I have come to think of copper in a different light.

I will still be using pex for areas which suit pex but I will also be a using copper now in areas I would not have before.


I would take the above considerations into account before choosing a product, leading out with cost.

If you feel like cooper is the best product for a job, tell the customer why, fight for the best.l product. Likewise if you feel pex best suits the installation due to high ph levels (acidic side) for example, let the customer know, they will be only to thank full for your advice and expert opinion.


Each product has its merits and is better suited to plumbing installations in certain conditions over the other.

Find the product which best suits and install, this way the customer gets the best product every time, not just because of price.

Thank you for reading my article.