The material used for sewer pipes in Finnish private houses was mainly cast iron until the 1970s, after which plastic pipes started to become more common. Old cast iron pipes are typically susceptible to water damage because over the years the pipes have been exposed to corrosion and other stresses, making them brittle.

Cast iron sewer service life varies

The lifetime of a cast iron sewer installed between 1950 and 1970 varies widely from source to source, the most common being 50 years. However, practical experience has shown that cast iron sewer pipes in a detached house sometimes reach the end of their useful life after only 30 years. However, there is a lot of variation, as the lifetime of a pipeline is influenced by many different factors. For example, dumping substances that do not belong in a sewer can significantly reduce its lifetime. In addition, the strength of the pipe wall varies. The thicker the wall, the longer the pipe will generally last.

Building magazine writes that cast iron pipes, even those made using modern techniques, have in some cases corroded after just two years as a result of poor installation. It should be noted, however, that today the wall thickness of a pipe is only 3.2 mm, whereas in the 1950s and 1960s the pipe walls were up to three times thicker. As a result, it takes longer from the time of installation before old cast iron drains corrode.

As a rule of thumb, the condition of a cast iron sewer should be checked at the latest when it is 25-30 years old. This will increase the likelihood of being able to react in time if the sewer turns out to be in poor condition. However, if the sewer was installed before the 1970s, renovation is very often necessary.

Why do you need to renovate your sewer?

A cracked old pipe can lead to water damage that you may not even notice right away. In the worst case, dirty water and bacteria can flow into the house for an extended period of time, causing damage to both the property and people. The gases rising from the sewage water can also cause corrosion of the upper part of the sewer pipe, resulting in holes that release gases into the breathing air, which can pose a health risk.

Drainage imaging reveals the true condition of the drain

If your house has old cast-iron pipes, consider a free sewer survey, which involves inserting a camera at the end of the cable into the sewer pipe. Although a sewer pipe may look fine from the outside, a sewer camera allows you to see its condition from the inside; corrosion can weaken the pipe in either direction. In addition, a pipe never deteriorates evenly; for example, the drainage pipes in the kitchen can be in much worse condition than the rest of the plumbing. Fortunately, the camera also allows you to see the part of the pipeline that is completely hidden from the residents. If, at the end of the sewer survey, it is determined that a renovation is necessary, we will provide a fixed-price offer at the same time. The description is truly free of charge and does not bind you to anything.

Cracked cast iron sewer pipe: