If you own an older home or manage a property with ageing cast iron pipes, you may want to check for issues like rust and leaks. Cast iron pipes deteriorate over time, leading to costly repairs or even full replacements.
But did you know there is a better way to restore them?
It’s called pipe relining, a modern, non-invasive solution that doesn’t require replacing your whole drainage system. Here, we’ll explore how cast iron relining works, why it’s becoming a preferred alternative to replacement and whether it’s the right choice for you.
What Are Cast Iron Pipes?
Cast iron pipes have been used in plumbing systems for centuries, dating back to Europe in the 17th century. By the late 19th and early 20th centuries, they became a standard choice for sewer and drainage systems in Australia. This was mainly due to its strength and durability. As a result, cast iron pipes were commonly installed in homes and commercial buildings up until the 1970s, including in Sydney.
Where Are They Commonly Found?
In Sydney, cast iron pipes are often found in older homes, heritage buildings, and some older commercial properties. They are typically used in stormwater drainage, underground sewer lines and vertical stacks in multi-storey buildings. During the 1970s, PVC and other modern materials started replacing them due to some common issues.
Common Issues with Cast Iron Pipes in Sydney
The pipes’ age and environmental factors affect deterioration. In Sydney, this includes:
- Corrosion and Rust: Being a coastal city, Sydney’s climate causes rusting in cast iron pipes.
- Blockages from Scale Build-Up: Mineral deposits and rust accumulate inside the pipe over time, restricting water flow.
- Cracks and Breaks: Soil movement and ground pressure can cause cast corroded iron pipes to crack, leading to leaks and structural damage.
- Tree Root Intrusion: Older cast iron pipes often have weak joints, and invasive tree roots seeking moisture can penetrate the cast iron plumbing.
What is Cast Iron Pipe Deterioration?
While cast iron pipes were once considered one of the most durable plumbing materials, without proper maintenance or repair, you can end up with deteriorating cast iron pipes.
Here are the signs of deterioration to look out for.
Leaks, Cracks, and Corrosion
Visible leaks or water damage around pipes often indicate deterioration. Rust and corrosion can weaken the pipe walls, leading to fractures. As cast iron pipes reach the end of their lifespan (typically 50-100 years), they corrode from the inside out. As previously mentioned, tree roots can enter weakened cracks, leading to damaged cast iron pipes.
Discoloured Water
Brown or yellow-tinted water is a telltale sign of rust buildup inside the pipes, which affects your water quality. High moisture levels, soil acidity, and extreme weather conditions can contribute to rust.
Slow Drainage or Backups
A failing cast iron pipe can cause frequent blockages or sewage backup, indicating internal damage or, worst case scenario, collapse.
Unpleasant Odours
This is mainly for sewer gas leaks caused by corrosion. It can lead to a foul stench in and around the property. Besides being highly unpleasant, it also poses a health risk.
Maintenance, regular inspections and drain cleaning help prevent premature deterioration. Conversely, neglect can lead to costly full replacements.
The Benefits of Cast Iron Pipe Relining
Pipe relining presents both cost-effective and environmental benefits.
Cost-Effective Solution
Pipe relining is typically completed within a day, making it significantly faster than traditional pipe replacement. Moreover, it eliminates the need for excavation, reducing downtime and inconvenience for homeowners and businesses. This also means there is less labour required, which means that it’s more affordable than traditional pipe repairs and replacement.
Environmental Benefits
Because of this lack of excavation, pipe relining reduces carbon emissions by up to 75% compared to traditional pipe replacement. It also helps preserve landscaping and infrastructure.
Additionally, the durable relining material is resistant to future wear and deterioration, which means that there’s less need for frequent repairs, further lowering its environmental impact.
The Cast Iron Pipe Relining Process
Both homeowners and businesses can benefit from relining as a durable and non-disruptive solution. There’s typically a five-step process to cast iron trenchless pipe relining.
1 – Inspection
First, a comprehensive video inspection is carried out to assess the condition inside your cast iron pipes. This is done by inserting a CCTV camera into your piping. It helps determine the extent of the damage and whether relining is your best solution.
2 – Clearing and cleaning
Once that’s confirmed, the pipes are thoroughly cleaned to remove any debris, corrosion, or blockages with a high-pressure hose. This ensures a smooth surface for the new lining.
3 – Liner Installation
Next, a flexible epoxy resin liner is inserted into the existing pipe. This liner is specifically designed to handle the unique demands of cast iron pipes. It reinforces the structure without the need for excavation.
4 – Curing
Once in place, the liner is cured, creating a strong, durable bond with the existing pipe. Finally, the relined pipe is tested to ensure its structural integrity and optimal flow, giving you a reliable, long-lasting solution.
5 – Testing
Finally, we test the relined pipe to ensure structural strength and optimal flow.
Limitations and Considerations of Relining Cast Iron Sewer Pipes
As good a solution as pipe relining is, it doesn’t come without its limitations. There are some cases where it may not be the best option.
Severe Damage
If a cast iron pipe has completely collapsed or is extensively damaged, relining may not be viable. Our experienced plumbers assess the condition of your pipes and recommend the most suitable solution.
Network Access
Older properties can have complex drainage systems that make access challenging. However, we use advanced technology to pinpoint problem areas which then allows us to explore innovative solutions.
Tree Root Invasion
If tree roots have severely infiltrated and grown throughout your pipe, relining may not be ideal as the roots can prevent the liner from sealing properly and this will cause future issues. Instead, we use specialised root removal tools and chemical root inhibitors to manage root growth and restore your pipe’s integrity.
Pipe Relining vs. Full Iron Pipe Replacement
Estimating Costs: Pipe Relining vs. Traditional Pipe Replacement Methods
When it comes to pipe repairs, the cost difference between pipe relining and full iron pipe replacement depends on several factors, such as the size of the pipe, the extent of damage, and how easily it’s accessed. This will help you make an informed decision.
What’s good to know is our team provides a clear and fully transparent quote, as well as warranties.
Maintenance and Durability
As for maintenance, keeping your relined pipes in good shape is key to getting the most out of them. And steer clear of pouring harsh chemicals—things like paint thinners or strong cleaners—down the drains.
Choosing a Professional Cast Iron Pipe Relining Company
In summary, cast iron pipe relining offers a non-invasive method with long-lasting results. Just be sure to choose a company with expertise and experience in cast iron pipe relining.
If you’re unsure which option is right for your home or business, our expert team at The Relining Company is here to help. Reach out anytime for a detailed estimate and professional advice on the best solution for your plumbing needs.
Frequently Asked Questions
Can you reline a cast iron drainpipe?
Absolutely! Cast iron drainpipes can be relined using the same trenchless technology as other pipe materials.
Can you put a liner in a cast iron pipe?
Yes, a durable liner can be inserted into cast iron pipes to restore their functionality without the need for full replacement.
What are the disadvantages of pipe relining?
While pipe relining is a cost-effective and non-invasive solution, it may not be suitable for severely damaged pipes or those with significant tree root growth.
How much does it cost to reline a cast iron pipe?
The cost of relining a cast iron pipe depends on factors like pipe size, accessibility, and the extent of damage, but it is generally more affordable than full replacement. You can get a better idea of cost here.
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