If your home still has cast iron pipes, there may come a time when they need to be replaced. For this task, it’s highly advisable to have an experienced professional handle the job, as they’ll have all the tools and safety equipment required.

Nonetheless, this blog post will go over all the necessary steps of how to cut cast iron pipes, including what tools professionals use. Here’s what you need to know.

What is a cast iron (CI) pipe? 

Cast iron pipes were widely utilized throughout history as conduits to facilitate drainage and transport water, gasses, and sewage waste. In plumbing systems, this material would often serve as drainage, sewer lines, or water supply lines.

This traditional material can still be found in older houses, as it was commonplace before the advent of plastic alternatives.

Why would you need to cut a cast iron pipe?

While cast iron itself is safe as a material, the joints and connections of the pipes may contain lead. This is considered a health hazard, as it can leak into the water. Not only can these pipes cause health problems and render a home uninhabitable, but they can also decrease a home’s value, potentially rendering it unsellable altogether.

This material will typically last 50 years. Any signs of wear and tear indicate that it may be time for a replacement.

Always enlist the help of a skilled professional to conduct the replacement, as they’ll have the experience, tools, and proper safety equipment to cut these pipes out from your system to replace them with newer and safer plastic alternatives.

The tools needed to cut a cast iron pipe

When it comes to how to cut a cast iron pipe, there are various methods a professional might use, which will require a variety of tools.

It’s important to note that standard cutters and saws are too weak for pipes of this thickness and weight, and a specialized chain-style cutter designed specifically for cast iron will be necessary. Therefore, the professional may use a reciprocating saw with a special cast iron blade.

An angle grinder is another classic choice. It can easily make cuts without excessive strain, and it’s a power tool that many professionals are familiar with. Care must be taken when operating it.

Another (and perhaps the most common) tool to use is the snap cutter, made up of a roller chain and ratchet to perform clean cuts. While this tool can be rented at a hardware store, a professional plumber will likely already have it on hand.

Some other things needed to carry out this project are some chalk, as well as eye and hearing protection.

A step-by-step on cutting a cast iron pipe

The actual step-by-step method on how to cut cast iron pipe will vary depending on the tool used. Here’s how a professional will usually execute this project.

Reciprocating saw

Here’s a step-by-step on cutting through the pipe with a reciprocating saw.

  1. To ensure clean and smooth edges when cutting, use a piece of chalk to mark the cut lines. Securely hold the pipe in place and draw straight lines.
  2. Equip the reciprocating saw with a durable, long metal cutting blade. These blades are specifically designed to handle tough materials like cast iron to ensure precise and clean cuts.
  3. To minimize blade wear, it’s recommended to apply a lubricant to the pipe. This will help prevent the blade and saw from getting worn out from the friction of cutting.
  4. To ensure the safe operation of the reciprocating saw, start by setting it to the lowest speed. Begin cutting at a controlled pace without exerting force. Applying excessive pressure or increasing the speed can potentially lead to blade breakage.
  5. To finish the cut, continue until the cast iron pipe is divided into two pieces. Once finished, carefully remove all filings and debris from the area to avoid clogging any pipes or damaging surrounding surfaces.

Angle grinder

For how to cut cast iron sewer pipe, here’s how a professional will use an angle grinder to do so.

  1. First, start by indicating the sections of the cast iron that will be cut by marking them with chalk.
  2. Fit the metal cutting blade and use a ratchet tool to securely tighten it. Be sure to properly fit it so that you are ready for safe operation.
  3. Ensure the pipe is securely in place. Then activate the angle grinder.
  4. Start cutting through, making a groove in order to weaken the surface.
  5. Carefully work your way around the cast iron, gradually grinding away until it’s completely separated.
  6. Given the toughness of cast iron, a cold chisel can be employed to effectively sever the rest.

Snap cutter

Here’s how to cut through cast iron pipes using a snap cutter.

  1. Apply a chalk line to the surface, marking the desired cut lines with precision and accuracy. Make sure that these lines are drawn as straight as possible in order to ensure a neat cut result.
  2. Position the snap cutter around the pipe and securely encircle it with the chain jaws. Make sure the chain is evenly wrapped with the cutting wheels against the pipe. Confirm the firm placement of both hooks on the surface, ensuring their open sides face upward.
  3. Tighten the snap cutter jaws by rotating the ratchet in a clockwise direction. Make sure that they are perpendicular to the pipe and that the cutting line is properly aligned with the chain.
  4. Exert pressure on the snap cutter handles until the enclosed cutting wheels start to penetrate the surface. Make multiple scores on the pipe before executing the final cut to achieve a more precise outcome.

Need help with your plumbing system? Get in touch with J. Blanton

So there you have it: how to cut cast iron pipe. This task should only be done by a professional plumber due to the potential danger risk. With a professional’s help, the job can be done efficiently and without difficulty.

If your home still has cast iron pipes and you want them replaced, consider contacting J. Blanton for help. J. Blanton has been a reliable plumbing service provider for Chicagoland homeowners for over 30 years. Our team of licensed plumbers guarantees customer satisfaction.

Contact J. Blanton today!