What is Cast Iron Pipe Lining and How It Works

Cast iron pipes have been a popular choice in plumbing for many years due to their strength and durability. They were widely used for both water supply and drainage systems. However, over time, these pipes can develop issues like cracks, leaks, and blockages. Replacing cast iron pipes can be costly, disruptive, and messy. That’s where cast iron pipe lining comes in.

This method allows you to repair damaged pipes without the need for full replacement. It’s a more affordable and less invasive solution that can extend the life of your pipes. 

In this article, we’ll explain what cast iron pipe lining is, how it works, and why it might be the best option for your plumbing. We’ll also cover its cost and when it makes more sense than replacing the pipes entirely.

What is Cast Iron Pipe Lining?

Cast iron pipe lining repairs old or damaged cast iron pipes. Instead of replacing the entire pipe, workers insert a special felt liner inside the pipe. This liner seals cracks, prevents leaks, and restores the pipe’s ability to let water or waste flow smoothly again.

The process starts with a camera inspection to identify cracks or blockages. After the team cleans the pipes, they coat a felt lining with a strong epoxy resin. They then push the lining into the old pipe using pressurized air, inflating it to fit snugly against the pipe’s walls. The resin cures with heat and pressure, creating a durable, new pipe inside the old one.

It’s a quick and non-invasive solution to pipe problems. The finished lining is strong, resistant to tree root intrusion, and can last for over 50 years, offering a long-term solution without the mess and cost of full pipe replacement.

How Does Cast Iron Pipe Lining Work?

Here’s how the process works:

1. Inspection and Cleaning: First, a plumber will check the pipes using a camera to see the damage. Then, they clean the inside of the pipes to remove any debris.
   
2. Preparing the Liner: The plumber prepares a liner made of resin (a strong material). This liner is ready to be inserted into the pipe.
   
3. Inserting the Liner: The liner is put into the pipe and inflated to fit snugly against the inside walls. Once it’s in place, the resin hardens.
   
4. Curing: The resin is cured using heat or UV light, hardening it into a solid, durable layer that forms a new pipe within the old one. This method is often referred to as Cured In Place Pipe Lining (CIPP), a technology that ensures a strong, long-lasting seal inside the pipe. To learn more about the CIPP process, you can explore our CIPP Pipe Lining Guide.
5. Final Check: After the liner is in place, the plumber will check the pipes again to make sure everything is working perfectly.

The EPA’s Guide on Cast Iron Pipe Replacement and Lining provides additional details on the methods used for both lining and replacing cast iron pipes, including surface preparation and adhesive application techniques. Read more here.

Why Choose Cast Iron Pipe Lining?

Here are some reasons why cast iron pipe lining might be the right choice for you:

1. It’s Cheaper: Lining the pipes is much less expensive than replacing them completely. You avoid the cost of digging up your yard or home.
2. Less Mess: Because there’s no digging involved, it’s a cleaner and faster process. Your daily life won’t be disrupted as much.
3. It Lasts Long: Once the liner is in place, it can last for many years, reducing the need for future repairs.
4. It’s Environmentally Friendly: Since there’s no need to replace the pipes or dig up your property, lining is a more eco-friendly option.
5. It Works for Many Issues: Whether your pipes have small cracks, leaks, or are simply old, lining can fix many problems without needing a full replacement.

Cast Iron Pipe Lining vs Replacement

Pipe relining vs replacement is a common question. While both options have their benefits, lining is usually more affordable and faster. Full cast iron pipe replacement can cost anywhere from $4,000 to $15,000, while lining cast iron pipes typically costs between $2,000 and $5,000.

If your pipes are only slightly damaged, lining cast iron pipes is often the better option. However, if the pipes are severely damaged or causing bigger issues, you might need to replace them.

DIY Cast Iron Pipe Lining: Is It a Good Idea?

Some homeowners might be tempted to try DIY cast iron pipe lining, but it’s not recommended. The process requires special tools and experience to ensure the liner fits properly and cures correctly. If not done right, it could lead to more issues down the road.

It’s always best to hire a professional plumber who has experience with lining cast iron pipes. This ensures that the job is done correctly and safely.

Conclusion

Cast iron pipe lining is an excellent solution for repairing old, cracked, or damaged cast iron pipes. It’s affordable, efficient, and long-lasting, making it a popular choice for many homeowners. If your pipes are starting to show signs of damage, consider lining cast iron pipes as a way to extend their life without the hassle and expense of full replacement.

For residents and businesses in the Dallas-Fort Worth area, NuFlow DFW offers expert trenchless solutions. Learn more about our services and how we can help you with pipe repairs.