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Cast Iron Pipe Clogged: 7 Easy Ways To Fix It!

Cast Iron Pipe Clogged: 7 Easy Ways To Fix It!

If you are using cast iron drain pipes and are hearing gurgling sounds from your sink and toilet, you likely have a clog. Cast iron, like any other plumbing material, can develop blockages with time, and it’s up to you to address the problem before things get worse. But how do you fix a clogged cast iron pipe?

We have several ways to solve clogs in your cast iron drain pipe. Some of the common fixes include:

  1. Hydro jetting
  2. Cabling
  3. Picote cleaning
  4. Using a drain cleaner
  5. Replacement

Some of these methods fall in the DIY category, while others require sophisticated tools only accessible through professional service. 

Today’s blog post is about the blockage problem you now have in your cast iron pipe. We’ll examine the potential causes, ways to fix the problem, and whether or not using some of the most debated products to dissolve the clog is okay. Keep following for all these and more!

Why Do Cast Iron Pipes Get Clogged?

Before we even delve into how to solve the issue, let’s examine how you ended up in the problem. After all, you’ll keep fighting an endless battle if you only work with the remedy part without identifying the root cause.

We’ve got several causes of clogs in cast iron pipes. 

They include:

  1. Flushing the wrong products
  2. Material’s textured surface
  3. Low flow toilets
  4. Tree roots
  5. “Bellies” in the pipe

Let’s take a quick look at these potential causes of clogs!

1. Flushing The Wrong Items Down The Toilet

By now, you should be knowing that not everything is meant to go down your toilet. One of the reasons you could be encountering issues with your cast iron drain pipes is because of flushing the wrong products down the toilet.

You see, more than a few people often yield to the temptation of using the toilet as a catch-all for everything they need to dispose of without realizing that their action might lead to issues that can be expensive to correct.

Of course, sometimes the repercussions may not be apparent immediately, but every time you send the wrong item down the toilet, the more your mistake draws you closer to a blockage problem.

Some of the products to keep off your toilet include:

Those are just a few everyday products that can cause blockages that are difficult to clear. So, if you’ve been flushing any of these, perhaps they got stuck somewhere within the piping and are causing the clog you now have.

2. Material’s Textured Surface

One of the reasons why cast iron pipes tend to be more susceptible to clogs than PVC and copper drain pipes is because of their textured surface.

You see, the textured surface can, over time, cause some materials to build up and accumulate on the pipes. That creates a rough surface that can trap more debris and waste, and that’s especially common in older cast iron pipes that have been in use for many years.

Some common culprits that can cause clogs in cast iron pipes include food waste, hair, soap scum, and minerals from hard water. These materials can stick to the textured surface of the pipes and slowly build up over time, eventually leading to blockages and clogs.

3. Low-Flow Toilets

Low-flow toilets came as a clever innovation to reduce the amount of water you use in every flush. That means they are more efficient than traditional toilets and a favorite candidate for everyone looking forward to reducing their water bills.

But did you know your water-efficient toilet could be why you’ve encountered those recurrent clogs with your cast iron pipes?

That’s right! 

As much as low-flow toilets are better than their older counterparts in several ways, they still have their downside!
Since these toilets require less water than the traditional models in every flush, they don’t possess as much flushing power as their counterparts, often resulting in incomplete waste removal.

4. Infiltration By Tree Roots

If your cast iron drain pipe has seen better days, or maybe you live in an area that experiences massive soil movement, chances are your pipe has a leaky spot. That means every time water flows down the pipe, some amount of water – and nutrients – ends up in the neighboring soil.

Over time, these compounds can attract the roots of surrounding trees, infiltrating the pipe. When that happens, it disrupts the smooth flow of water and waste, often leading to stubborn clogs.

5. Bellies in The Pipe

For the uninitiated, bellies are sagging or low spots along your cast iron sewer line where water and waste can accumulate and cause clogs eventually.

The “bellies” can be caused by either of the following:

  • Improper installation
  • Severe soil movement
  • Natural wear and tear over time

Unfortunately, these depressions can be hard to detect, although the repercussions aren’t as subtle. If you’ve noticed slow drainage recently or had recurrent clogs, they could be the cause.

If you’re unsure, get a professional to inspect the plumbing system. Using their expertise and sophisticated tools, the expert will try to detect if your piping has this problem. Then, they’ll deploy any necessary corrective measures to avoid more severe consequences.

Does Drano Hurt Cast Iron Pipes?

No, Drano won’t hurt your cast iron pipes. According to the product’s manufacturer, Drano is safe for plastic and metal pipes and won’t harm either. In fact, the product has a special ingredient that prevents pipe corrosion.

As a homeowner, you need to always act cautiously when choosing the products for use on your plumbing system. That’s especially true when working with commercial cleaners or clog removers.

Most commercial products are not pH-balanced to suit use on metallic pipes, quickening the corrosion and rusting process on some metals.

But the same can’t be said of Drano!

Based on the manufacturer’s information, Drano Max Gel Clog Remover isn’t like other cleaners. Unlike them, Drano doesn’t contain acids like sulfuric and hydrochloric, making it safe for use on plastic and metal pipes. 

But as usual, follow the manufacturer’s directions on how to use the product. That way, you’ll make the most out of your purchase and elude any potential issues of improper product use.

7 Ways To Fix a Clogged Cast Iron Pipe

Now that you know the potential causes of the clog in your cast iron pipe, let’s get into the nitty-gritty of this article; how you can fix the problem at hand.  

Well, we’ve got several corrective measures you can take depending on the cause of the problem!

1. Proper Toilet Use

While it may sound more of a preventive measure, that’s not actually the case. By embracing good practices, you’ll keep the clog from worsening when working around it and from coming back shortly after you’ve resolved it.

So, ensure that you only use your toilet appropriately. Keep off items that aren’t meant to go down your sewer line. 

Generally, the only products you can safely flush down your toilet are human waste and a moderate amount of toilet paper. Anything outside that is a no-no. Not even the “flushable” baby wipes! 

2. Bring in a Plunger

A plunger is one tool that often produces moments of magic when we desperately need them. So, before you employ sophisticated tools and techniques, turn to your trusty plunger!

Position the plunger well, ensuring the head is partially covered by water. Then, give several pumps for about a minute or two. If possible, apply some jelly on the edges of the head for a stronger vacuum. 

If the clog isn’t a serious one, a plumber should suffice. Otherwise, you’ll need to use a different technique to remove the blockage.

3. Cabling

If the plunger doesn’t do the trick, bring in a drain snake. Run the cable down the plumbing system. Then, connecting the cable’s end to a drill, spin it to disengage the clog. Most of the time, the force generated from the drill should do the trick.

For higher chances of success, pour hot water down the plumbing system before attempting clog removal.  It will soften the clog, making it easier to break it up!

4. Use Specialized Cleaning Products

You can also consider using specialized cleaning products to solve the clog issue. However, it’s good to remember that unlike PVC, metallic pipes, especially those made of cast iron, can pick up adverse effects from the wrong choice of cleaning product.

Only work with specialized cleaning products. We’ve got several products specially formulated for cast iron pipes, so use them instead. It will save you the high cost of professional service and safeguard you from future troubles with your plumbing system!

5. Hydro Jetting

If the DIY techniques discussed above don’t yield any fruits, it’s time to use more sophisticated techniques like hydro jetting.

This technique comes with professionals and involves using a specialized nozzle to shoot a stream of water at a whopping pressure of 4000 PSI to slice through the dirt, debris, and other things causing the blockage.

Of course, since it involves working with professionals, expect this technique to cost you a good amount of bucks. That means you work with a reputable professional who delivers up to the tag!

6. Picote Cleaning

This is another technique you can use to get rid of that clog. It’s similar to hydro jetting, only that it uses high-powered air instead of water.

When using this clog disintegration technique, a chain is adjusted depending on the thickness of the pipe before being spun in a cyclone pattern. 

The setting of the chain is so that it rotates within the pipe without hitting the edges of the pipe, ensuring that it doesn’t leave any marks or other forms of damage to your cast iron.

So, consider this method if you’re looking for a clever way to eliminate that clog without damaging the sewer pipe. But then, this innovation comes with a hefty price tag. That’s to say, think long and hard before choosing it!

7. Switch To PVC Pipes

While cast iron pipes are very durable, they eventually need replacement. Hence, if you’ve noticed frequent problems with your plumbing system, it may be a signal that you need replacement. 

Sure, replacement is much more expensive than any of the corrective measures. But then, even when you opt for other remedies, you’ll still need to change the pipes over time, so any postponement can only make it more expensive.


Although cast iron pipes are durable, they can be susceptible to clogs occasionally. But thankfully, we’ve got several ways you can clear the blockage and restore the full functionality of your plumbing system. Just exercise caution when addressing a clog to avoid causing further damage in the short or long term.