Many older homes in today's marketplace still utilize older cast iron waste lines in the plumbing system. This material is easily identified by its metallic appearance. It was put together utilizing a bell or hub male and female system and the connections were tucked with oakum and filled with molten lead. The repairs for these old waste lines can be quite costly. Potential home buyers need to understand a few important things when it comes to old cast iron waste lines.
First of all Cast iron materials are no longer used and haven't really been in use for a few decades now. Most older cast iron materials were installed from the 1930's to early 1960's. What does this mean? It means this material is now 50-80 years old. More importantly, what is the typical life expectancy of this old material. Above ground usage in walls, ceilings, and basement areas had a typical life expectancy of 60-70 years. Below grade usage such as under slabs, or buried in the ground running out to the city sewer had only a 50 year life expectancy. Thus, we are now well within these time frames where repair and replacement are imminent.
Repair / replacement of the above ground aspects is relatively simple and can be easily performed by a certified plumber and even a homeowner with some basic skills. Replacement of the old cast iron waste lines would now be done utilizing PVC schedule 40 material. Fittings are easily cut and glued into place. Repair / replacement of below grade aspects is much more expensive. In our experience we have seen many waste line aspects that run under porches, slabs, driveways, swimming pools, garages, etc. Tree root intrusion also can significantly damage these old lines. These lines can also simply become brittle and collapse leading to blockages and back-ups into the structure. Not a pleasant experience. These subsurface lines are also generally several feet below grade and require the use of a backhoe to replace. There are many factors that dictate the actual replacement cost but certainly one would be looking at several thousand dollars.
As a home inspector when cast iron lines are visible we will note the concern to our clients. Often times we see various pvc replacement that has been done within a structure but still observe cast iron lines leaving the structure. One option available to a potential buyer is to have a professional plumber come in and conduct a video evaluation of the line all the way out to the street. This is achieved by running a camera down the line and videoing the line all the way out to the main sewer tap on. The cost range to have this done is $ 300 – 500 dollars. It may be money well spent. There are also insurance / warranty programs available today that cover the cost of repairs. Some offer a 24 hour emergency hotline phone number. Some Homeowner insurance policies cover such repairs and others do not. A homeowner may want to check into their specific policy to see whether or not these type of repairs are covered.