If you own a building that was built as far back as the 1800s and you are having sewage blockage and drainage problems, it could be caused by a failing cast iron sewer pipe. Here is some information to help you determine if the sewer line is failing, what may be causing its failure, and how you can remedy it.
Determine if Your Building Has a Cast Iron Sewer Pipe
Cast iron sewer pipes began to be used to transport water and waste in the early 1800s, and are one of the oldest types of sewer pipe that are still around today in many buildings. This pipe was installed as a sewer line in buildings and residential homes up until the 1970s, when PVC became a more lasting option. If your building was built before the 1970s, the chances are increased for this type of pipe to be used in the sewer and waste water pipe system.
When determining the type of sewer line is in your building, it can be helpful to eliminate the possibility another type of sewer line was originally installed. In a building that was built during the time cast iron was used as sewer pipes, there is a chance Orangeburg or clay pipe was used. Orangeburg pipe is made of layers of wood pulp impregnated with coal tar, and clay pipe is made from a brittle clay material.
Both of these old types of sewer pipe materials do not last as long as cast iron and can be likely to fail long before a cast iron pipe. Orangeburg pipe usually only lasts 50 years in ideal conditions and clay pipe only lasts for 50 to 60 years. So, check into the construction date of your building to help you determine if it could possibly have either of these two types of pipe in the sewage system.
You can also hire a professional plumber to do a video inspection of the interior of the sewer pipe to determine its make-up and its condition, especially if you are experiencing clogs and drainage problems in your building. They will be able to see if the pipe has cracking and other problems that can cause pipe failure and determine its material make-up.
Understand What Can Cause Cast Iron Pipe Damage
Cast iron pipes were built as a durable sewage system to last anywhere from 75 to 100 years under the most ideal conditions. Unfortunately, they can begin to break down from their interior and ultimately fail, causing clogs and sewer back-ups well before their expected 100 years of use. For example, an inspection company found one cast iron pipe excavated after 40 years and already badly deteriorated.
The waste that travels through a cast iron sewer pipe produces hydrogen sulfide gas, which reacts with the iron to oxidize and create sulfuric acid. Sulfuric acid corrodes the cast iron and eats away at it from the inside. This type of erosion can occur especially along weakened seams in the pipe and along the top of the pipe's interior where the hydrogen sulfide gas collects and increases the acid in the pipe.
Cast iron pipes were produced during its time with varying levels of quality, some sections of pipe and seams may have been thinner than others, leading to break-down and failure sooner than other areas. Also, increased use of drain cleaners that contain sulfuric acid increase this corrosive damage to a cast iron sewer line in your building.
The soil around your building's aging cast iron pipe can shift from natural earth movement and from nearby excavation work, and the growth of tree roots into and around the pipe can all cause a pipe to receive further damage.
Decide How To Repair the Building's Sewer Line
Cast iron pipe is a type of material that is best replaced in its entirety, instead of patching and replacing in sections. The reason for this is because when one section of the pipe begins to leak from interior corrosion, the rest of the pipe is likely in the same condition. This will ultimately lead to failure over other areas of the pipe, and patching to repair the pipe in small sections will continue until the entire length of pipe is replaced. Unfortunately, patched sections are more likely to fail, as the repair is not as strong as the original pipe or a new replacement PVC pipe.
For this reason, it is recommended to hire a plumbing professional to remove the entire cast iron pipe and replace it with a PVC pipe that will last 100 years.