One of the many things you can’t (or at least shouldn’t) put off when it comes to maintaining your home is the waste pipes. Old waste pipes can easily lead to very large damages and expensive renovations. For that reason, many people today advocate plastic pipes in the sewers. But is it really a better solution than cast iron and what disadvantages do they bring?
Waste pipes in cast iron during the 20th century
First of all, we need to differentiate a little between plastic and plastic and cast iron and cast iron. Cast iron pipes manufactured and installed during the early 20th century were generally of very good quality and thick. These could be expected to last up to 80 years under very favorable conditions. Cast iron sewer pipes that began to be used around the middle of the 20th century were not quite as high quality and were thinner. Here, one could count on a maximum lifespan of just under 50 years. This means that all such pipes left in houses around Sweden are living on borrowed time!
The plastic pipes take over
During the 1960s, plastic began to be used and became dominant during the 1970s. The problem was that the first plastic pipes were of poorer quality than the cast iron pipes they replaced. The substances that held the plastic together and prevented it from drying out were washed away with the sewage, leaving brittle sewer pipes that could start leaking at any moment.
From the 80s onwards, however, the plastic has been made of very durable material. Such a sewer pipe can easily last 100 years under suitable conditions.
The return of cast iron
As with all stories, we have a hero who steps down at the beginning of the story, whereupon another character takes over the leadership torch. Towards the end of the stories, however, something happens that causes the hero to pick himself up and come back, stronger than ever!
Is this the story that plays out with cast iron waste pipes too?
There are many reasons for us to choose one or the other type of drain pipe. Just like everything else, this sort of thing comes in waves. For a long time, we‘ve been living in a kind of rationalistic drive for efficiency. Old, tried and tested methods, but perhaps not the most effective, have been rejected. Many amazing materials have been invented in the pursuit of the perfect sewer pipe. However, many of these have had rather serious negative consequences for us and our world after a while.
Why not plastic?
Plastic is such a material. It is probably the best material man has ever invented, from an efficiency perspective. Cheap to create, easy to shape, can be made incredibly thin and strong at the same time. It weighs next to nothing and lasts incredibly long. The downside, however, is that it has proven to be very harmful to us humans. Unfortunately it is specifically many of the positive properties that make it extra harmful.
We knew long ago that littering is a big problem and solve it with recycling. Another problem that arises is microplastics. When the plastic packaging we recycle breaks down, microplastics are created which can be very difficult to control. The long lifespan means that microplastics can remain in their form for a very long time. Recently, e.g. for the first time microplastics in the human bloodstream.
Cast iron waste pipes, then?
The disadvantages of cast iron do not have the same devastating effect on humans and other living organisms. However, it is cumbersome to handle, more difficult to shape and produce, and breaks more quickly. However, iron is an element that the human body and all other living organisms have lived with throughout our existence. It can be thrown in the forest (even if you shouldn’t) and it breaks down to 100% by natural processes.
Which way, modern man?
There’s a reason why the million-year-old water you buy in a PET bottle has a best-before date of a couple of months.
Personally, I think it’s fantastic that people are starting to look at reintroducing cast iron into Swedish homes. At the same time, plastic is a very good material and I am in favor of continued use of plastic to a limited extent. However, one must be very careful not to use too much plastic in equipment that comes into contact with food, water and things we eat, drink and use directly on the skin. PEX pipes, just like plastic drains, have become very popular and although they do not have any known toxins in them that we can ingest, any plastic particles that escape from the pipes remain in our bodies, bloodstreams and in our internal organs for months.
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