It is common for older homes built in the 1970s and before to have aging home systems that may need repair or replacement. Your own home's sewer pipe system may be at the end of its life and need to be fixed. Here are two types of sewer pipe that were commonly installed in older homes, how long they can be expected to last, and what you can do when they need repair or replacement.
If your home was built before 1980, clay sewer pipe was most likely used for your home's main sewer line to connect your home system to the city's main sewer line. Unfortunately, clay pipe only lasts for approximately 50 to 60 years. When your home's main sewer line begins to break down, you may have sewage backing up into your home through shower and bathtub drains, and toilets.
When the clay pipe was originally installed in your yard to connect your home to the city sewer, the sections of pipe were joined together using cement or mastic. Unfortunately, this material breaks down with age, allowing moisture to leak from the clay pipes. Tree roots naturally seek out moisture in the soil, so they will be attracted to the moisture collecting around the sewer pipes and grow through the pipe's cracked seal and into the clay pipe. Once the roots are inside your clay pipe, they get fed by the waste's nutrients and quickly fill the sewer pipe. Occasionally, the weight of the soil on top of the clay pipe along with the pressure from the tree roots will crack the clay sewer pipe, causing it to collapse.
You can hire a plumber to clean out your sewer line, but it will only provide temporary relief to the problem. The tree roots will continue to grow and cause plumbing to backup in your home. To repair your sewer line, you should replace it with plastic PVC pipe, which can last for many more years. A plumbing professional can excavate your yard to replace your old pipe with a new sewer pipe. You can also hire a plumber to replace your old sewer line by using a trenchless method. The trenchless method inserts the new pipe through the old pipe without digging up the entire length of pipe.
If your home was built before 1960, chances are pretty good your home sewage system was installed with a cast iron sewer pipe. Cast iron was commonly used in vertical and horizontal drain lines running under and through your home and in your home's vent stack. Cast iron pipes should last from 75 to 100 years, but under certain conditions their lifetime can be shortened.
Because cast iron easily corrodes and rusts when it is in contact with water and other waste, the constant flow of waste water can cause the bottom of the pipe to completely rust away. Then, the soil under the pipe will begin to erode away as the waste runs through the ditch it has created in place of where the pipe used to be.
Because many cast iron sewer pipes are used to move sewage waste from your home, hydrogen sulfide gas forms from the waste and oxidizes to produce sulfuric acid. Over time this sulfuric acid corrodes the cast iron pipe, causing leaks in the form of cracks and holes. Drain cleaners used in your home's pipes can contain sulfuric acid, which can speed up the corrosion in your pipes and cause damage sooner.
A professional plumber can replace a section or the entire length of your damaged cast iron pipe with PVC, depending on the damage and the age of the pipe. Click here to find out more about drain cleaning and plumbing services.
Keep in mind this information about cast iron and clay pipes and if your home has them installed because they may be at the end of their life and need replacing.