How To Clean Cast Iron Pipes

Last Updated On August 8, 2022
How To Clean Cast Iron Pipes

Cast iron pipes were once a popular choice for water transportation because of their strength and durability. While cast iron has primarily been replaced with newer materials to eliminate the possibility of corrosion, many homes still use cast iron pipes.

An old pipe can become dirty or clogged over time, which can lead to decreased water flow and other plumbing problems. Learn how to clean cast iron pipes the right way so that you can keep them functioning properly!

In this PlumbingNav guide, we will cover:

  • How to clean old cast iron pipe
  • How to clean cast iron sewer pipe
  • Cast iron pipe descaler
  • How to unclog cast iron pipe
  • Is sulfuric acid drain cleaner safe for cast iron pipe?

What's In This Guide?

      Why and How To Clean Cast Iron Pipes

      Cast iron piping and ductile iron pipe were recently the material of choice for drain, waste, and vent lines in commercial and residential buildings due to their durability and strength. 

      However, cast iron pipes can succumb to pipe corrosion more often than new, modern materials, such as plastic PVC pipe. The rusting that occurs due to corrosion can deteriorate the pipes, leading to water damage, and get into your water system, contaminating your home’s drinking water

      While you may want to consider an upgrade for your potable water system, you can clean your cast iron drain pipes and vent pipes to help them last as long as possible. 

      One of the most effective ways to clean cast iron pipes is cast iron pipe descaler. However, if you don’t have a descaler available, you can use a solution of vinegar and baking soda. 

      On top of cleaning the outside of the pipes, consider implementing a plumbing maintenance program that includes a safe and all-natural enzymatic drain cleaner

      Cast Iron Pipe Descaler

      A cast iron pipe descaler is a cleanser that removes mineral deposits and other debris from your cast iron pipes. Pipe descaling is easy to do and effective if you have the right tools, and you can do cast iron pipe descaling yourself.

      Look for products that won’t corrode the material or release toxins into the air with harsh chemicals made from 100% plant-based products. Yep, they’re out there!

      did you know How To Clean Cast Iron Pipes

      How To Unclog Cast Iron Pipes

      Cast iron pipes are one of the most durable and long-lasting options for plumbing, but they can still become clogged over time. There are a few different ways to unclog cast iron pipes, but the best method will depend on the location and severity of the clog. 

      For minor, local clogs in your drain pipe, a plunger or plumber’s snake can usually clear the blockage. We suggest these tools since, when used properly, they won’t cause any damage to older pipe materials. Of course, that’s why it’s especially important to use the right tool for the job.    

      If the clog is more significant, you may need to use a power auger or chemical drain cleaners. 

      An electric snake feeds into your drain like a drain snake, but it reaches further into the drain and generates more power. 

      Watch the video below to learn how to properly use an electric snake:


      If the electric snake can’t reach the clog, you may want to opt for a chemical drain cleaner.

      When selecting a drain cleaner for cast iron pipes, you need to be especially careful not to pick something that will corrode the material. Read our review of the best drain cleaners for cast iron pipes to learn more.

      Is Sulfuric Acid Drain Cleaner Safe For Cast Iron Pipes?

      When cast iron pipes become clogged, homeowners often turn to sulfuric acid drain cleaners as a way to break down the clog and clear the pipe. While sulfuric acid can be effective in breaking down clogs, it is also very corrosive. As a result, it is not recommended for use on cast iron pipes. 

      Sulfuric acid can eat away at the protective coating on cast iron pipes, leading to leaks and eventually failure of the pipe. If you have cast iron pipes, it is best to avoid using sulfuric acid drain cleaners. There are other ways to clear clogs that will not damage your pipes.

      How To Clean Iron Sewer Pipes

      Your cast iron sewer pipe runs underground, making it especially difficult to access. To determine the cause and location of the clog, you can get a professional sewer camera inspection and pick the best choice based on the results.

      There are a few different methods that can be used to clean cast iron sewer pipe (mentioned above), but the most effective way is to use a high-pressure water jet. 

      This will remove any build-up on the walls of the pipe and also help to break up any clogs that may have formed. Another option is to use a rotating brush, but this can damage the pipe if it is not used carefully. 

      If you are not sure how to properly clean cast iron sewer pipe, it is best to hire professional plumbing services to do the job for you.

      In some extreme cases or severe damage and corrosion, cast iron pipes may need to be replaced with trenchless sewer line replacement methods instead of spending the money on cast iron repair. 

      The two main types of trenchless repair methods are pipe bursting and CIPP pipe relining, depending on the specific circumstances. In both instances, the cast iron pipe will be replaced with new material.

      Both hydro jetting and trenchless pipe replacement require the assistance of a professional plumber. However, with proper care and maintenance, cast iron pipes can last for many years without needing to be replaced.

      Frequently Asked Questions on How to Clean Cast Iron Pipes

      What drain cleaners are safe for cast iron pipes?

      While cast iron can be vulnerable to corrosion, you can still find many drain cleaners safe for cast iron pipes. 

      Start by using vinegar and baking soda. If that doesn’t work, look for chemical drain cleaners safe for cast iron pipes.

      How do you clean the inside of a cast iron sewer pipe?

      Since you can’t easily reach your cast iron sewer pipe, you will need assistance in the form of an electric drain snake. If that doesn’t work, you can hire hydrojetting services.

      How do you keep a cast iron pipe from clogging?

      Prevent your cast iron pipe from clogging in the first place by being especially mindful of what you put down your drain. You should also use a safe enzymatic drain cleaner every season as part of your regular plumbing maintenance plan.

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      About Plumbing Navigator

      We write about "all things plumbing," helping you navigate common questions, repairs, and the best plumbing products on the market.

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      We write about “all things plumbing,” helping you navigate common questions, repairs, and the best plumbing products on the market.

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