How do you connect cast iron to PVC?

Asked By: Eneida Marca | Last Updated: 23rd January, 2020
Category: home and garden home appliances
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First cut your PVC pipe so it is longer and can be inserted a good 6 inches into the cast iron pipe without restricting any other flow in the system. Place the rubber union on the PVC Pipe and then insert the PVC pipe into the center of the cast iron pipe. Now tighten down the hose clamps to make the connection.

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Then, can you glue PVC to cast iron?

You can't glue PVC to cast iron. What you have there is a 4" cast iron hub. There is a flange that should fit your needs. It's made in PVC or ABS.

Beside above, will 3 PVC fit inside 4 cast iron? If the old timmer is talking about replacing all the the old 4" cast iron above ground with 3" PVC and then sleeving the 4" cast iron underground using an approved transition fitting at the point where the cast iron meets the PVC, then yes it's permitted.

Regarding this, how are cast iron drain pipes joined together?

DWV or drain waste vent pipe. These cast iron pipes have a “bell” or “hub” on one end and the smaller end of another pipe fits into it. The “joint” is then packed with a product called oakum. Then topped off with molten lead to seal the joint and prevent movement and possible future leaks.

Is PVC better than cast iron?

Cast iron pipe prevents the spread of fire much better than plastic pipe because cast- iron is not combustible. On the other hand, combustible pipe such as PVC and ABS, can burn away, creating an opening through which flames can move from one part of the building to the next.

35 Related Question Answers Found

Should I replace cast iron waste pipe?

Based on the fact that all cast iron sewer pipes will need to be replaced, we strongly recommend that cast iron pipe under a concrete slab be replaced and not repaired. In fact, we have decided we will no longer locate or spot repair any sewer leaks on a cast iron system.

Are cast iron pipes bad?

While it can be more brittle than pure iron, it is extremely durable and can withstand high amounts of pressure. The downside of cast iron pipes is that they are susceptible to corrosion (rust), which causes 25% of pipe failures. Depending on the environment, corrosion can damage pipes in as little as 25 to 40 years.

How much does it cost to replace a cast iron waste pipe?

Cast Iron Drain Pipe Replacement Cost. Replacing your pipes can cost you $200 to as much as $15,000. This range depends on the size of the project, materials used and labor. Some jobs require extensive cutting into walls or flooring, which can dramatically increase the labor time.

How do you take apart an old cast iron pipe?

The job requires a few hand tools and a cast-iron snap cutter.
  1. Install a 14/-inch drill bit into a cordless drill.
  2. Pry out the lead, using a flathead screwdriver.
  3. Fit the chain on the snap-cutters around a cast-iron pipe to cut it into shorter sections.
  4. Compress the handles to snap-cut the pipe at that point.

How do you reseal a cast iron drain pipe?


  1. Step 1: Clean Away Corrosion. If water or a bad smell comes from an old leaded joint, use a cold chisel and hammer to gently tap the lead back into the joint.
  2. Step 2: Fill with Repair Paste. Fill the resulting void with cast-iron pipe repair paste.
  3. Step 3: Fill Any Holes.

How do you repair cast iron lead oakum joint?

In some situations using oakum to seal a cast-iron pipe joint is still a viable option.
  1. Step 1: Remove lead and oakum remnants from the joint to be packed.
  2. Step 2: Loosely roll the oakum to form a workable length.
  3. Step 3: Insert the smaller pipe into the hub.

How do you loosen a cast iron fitting?

  1. Spray lubricant around the rim of the plug, aiming the spray to get as much of it into the threads as possible.
  2. Tap the rim of the plug a few times with a hammer to loosen the threads.
  3. Tighten one 18-inch pipe wrench onto the square nut on the top of the plug another around the drain pipe.

What is oakum made of?

In modern times, the fibrous material used in oakum comes from virgin hemp or jute. In plumbing and marine applications, the fibers are impregnated with tar or a tar-like substance, traditionally pine tar (also called 'Stockholm tar'), an amber-coloured pitch made from pine sap.

Which is stronger ABS or PVC?

Strengths & Weaknesses of Plastic Pipes
For example, PVC is more flexible, but ABS is stronger and more shock resistant. ABS is better at handling severely cold temperatures, but it can warp with exposure to direct sunlight. PVC is thought to be better at muffling the sound of running water.

What is cast iron soil pipe?


Material Cast Iron Soil Pipe
Hubless pipe is simply pipe with no hub or “bell” on the end. This material is used primarily to convey waste product and storm water from a structure and to allow airflow within a waste system.

How do you remove cast iron oakum?

Disconnecting a lead & oakum seal on a cast iron drain pipe
  1. If you have cast iron drain (waste) pipes they are likely joined with a lead & Oakum seal.
  2. It is possible to remove the lead and oakum.
  3. At this point you can use a small blowtorch to slowly melt the remaining lead.
  4. Now you have a clean hub connection to fit your donut into.

Can rubber couplings be used underground?

Teh all rubber "Fernco" is ONLY permitted underground "outside" the building. The banded ones are used indoors, and if they could not be used underground there is no way we could install cast iron drain systems.

Can you cut cast iron?

Solid cast iron can come in the form of griddles, old fireplaces or even wood-burning stoves. But when cutting through solid cast iron, a saw or cutting tool with a diamond saw blade is the best choice to make a cut in a straight line.

How do you install an offset toilet flange?


Insert the new hardware bolts into the offset flange. Place the double-thick wax ring on the flange, waxy side up, with the short rim inserted into the flange opening. Replace the toilet by carefully lining up the holes at the base with the bolts sticking out of the new offset flange.

What size is cast iron drain pipe?

Service Cast Iron
Size (in) Inside Diameter of Hub (in) Inside Diameter barrel (in)
5 5.94 4.94
6 6.94 5.94
8 9.25 7.94
10 11.38 9.94

How do you move a cast iron toilet?

  1. Install a new PVC toilet flange in the floor at the new location of the toilet.
  2. Drill a 5-inch hole in the floor using a drill and hole saw at the flange center mark you made.
  3. Cut the cast iron toilet drain with a cast iron snapping tool.
  4. Slide the rubber coupling half its length onto the cast iron pipe.