Did you know that your flat roof has cast iron downspouts located throughout your building? These downspouts span from the roof to the stormwater drainage system, and they help ensure that water drains from your roof any time it rains. However, since these pipes are made of cast iron, they are prone to corroding and rusting over time, which can lead to leaks inside your walls. Here at NuFlow, serving the entire Chicago area, we line cast iron downspouts.

Understanding Cast Iron Rain Drains

Cast iron is one of the most common plumbing materials. It’s used for rain drains and for vertical and horizontal sewer lines. It has an expected lifespan of 50 or more years, and it’s been installed in commercial, industrial and large residential buildings for more than 100 years.

Common Problems with Cast Iron Pipes

  • Bad Retrofits – Improper fittings and clamps used to connect new pipes to existing cast iron pipes
  • Corrosion and Rust – Caused by acidic water and the oxidizing reaction between iron and metal that causes rust and pipe degradation
  • Holes, Cracks and Splits – Can occur due to excessive corrosion, pipe shifting and freezing conditions
  • Improperly Anchored – Pipe movement and shifting due to poorly supported and anchored cast iron pipe

Causes of Cast Iron Corrosion

The corrosion of cast iron pipes can occur on the inside of the pipe and the outside. When corrosion and rust occur on the inside of the pipe, it is due to the interaction between the rainwater and the metal of the drain pipe. When corrosion occurs on the outside of the pipe, it is due to high humidity and moisture collecting on the exterior pipe wall.

Benefits of Pipelining Rain Drain Stacks

The primary cause of cast iron pipe failure is corrosion and rust. Since corrosion and rust occur every time the cast iron comes in contact with water or moisture, the best way to handle the problem is by lining the pipe with epoxy. This prevents water from coming into contact with the metal of the pipe.

  • Prevents future corrosion
  • Extends the useful life of the drain pipe
  • Seals existing cracks and holes
  • Relatively quiet process compared to traditional pipe replacement
  • Only takes a day to install a liner
  • Comes with a 10-year warranty

How Cast Iron Downspouts are Lined with Epoxy

Lining cast iron downspouts begins with a camera inspection to identify any cracks and holes in the pipe and the severity of the issue. This can be performed at the beginning of the pipelining installation process or initial visit or during a building pipe assessment.

1. Precision Pipe Cleaning

Next, the pipe is precisely cleaned using a pipe cleaner that is the exact diameter of the pipe. This pipe cleaner typically consists of rotating chains that scrape all the debris off the pipe walls, leaving them relatively smooth. Next, a gritty shot-like material may be blown through the pipe to help remove any debris that was left behind and to prepare it to accept the epoxy pipe liner.

2. Preparing the Felt Liner

Our pipe liners at NuFlow are constructed from heavy-duty felt, which forms the base of our epoxy pipe within a pipe system. This felt is prepared for insertion by scoring the material in precise locations. Once the liner has been scored, our two-part epoxy is mixed and poured down the inside of the liner. Next, we use a roller to squish the epoxy through the liner until it is fully saturated.

3. Pipe Liner Installation

The liner is then inserted into the drain stack and inflated using an air bladder. The air bladder ensures that the epoxy liner is fully pressed against the host pipe’s interior walls. Once the bladder is fully inflated, it is not removed right away. Instead, it is left in place for the entire curing process.

4. Pipe Liner Curing

The curing process takes about 24 hours. This gives the epoxy time to harden and cure. The next day, the air bladder is removed and the liner is inspected to ensure that the installation process was a success.

5. Your New Pipe Within a Pipe

Once the liner is in place, it acts just like a new drain pipe. When it rains, water flows from your roof down the new epoxy pipe and into the sewer system. This prevents future corrosion and pipe deterioration because the cast iron does not come into direct contact with future rainwater.

Determining if Cast Iron Pipelining Is Right for Your Chicago Building

Cast iron pipelining is a great way to restore your drain stacks and sewer stacks and extend their useful lives so that you do not have to rip out drywall and other finishes that could result in increased pipe replacement costs. The process is also much quieter and less intrusive than having your drain and sewer stacks completely replaced. If you are unsure if epoxy pipelining would be right for your plumbing pipes, our technicians can come out and inspect your old worn-out pipes to determine if they would benefit from epoxy pipelining.

To learn more about how we can help you eliminate rain drain cracks and prevent future cracks, give us a call at 815-790-9000.