What cast iron drain pipe replacement costs in Los Angeles

We found no Los Angeles price list for replacing cast iron drain pipe, so every figure here is a national one. A section under a concrete slab usually runs $3,000 to $15,000 or more with the concrete work, and some guides put it near $150 to $250 per foot. An exposed section in a crawl space or garage costs far less, often a few hundred dollars to $1,500, depending on length and fittings. Local labor rates are high, so treat these as a starting point for a conversation.

Cast iron carries waste inside many older homes, and it rusts from the inside until it clogs or leaks. If you are chasing slow drains and drain vents, a failing cast iron stack is one possible cause. This page prices the replacement and explains why the same pipe can cost a few hundred dollars in one house and thousands in another.

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

Plan on a total from a few hundred dollars for an exposed section to $3,000 to $15,000 or more under a slab, depending on where the pipe runs. The pipe itself is a small share. Almost the entire cost is labor, access and putting the house back together. We found no Los Angeles figure, so ask for written quotes.

These come from national cost guides, which disagree with each other, and none is specific to Los Angeles. Use them to frame a conversation, then get a written quote for your own house.

Why is cast iron replacement priced by where the pipe runs?

Because access is the whole job. An exposed pipe in a crawl space is cut, removed and replaced in a few hours. A pipe under a slab needs a jackhammer, excavation, new pipe, backfill and a new patch of concrete. Walls need opening and closing. The same four feet of pipe can cost ten times more under a slab than in a garage.

Slab work also brings costs that are not plumbing: replacing tile or flooring on top of the patch, and sometimes living elsewhere for a few days. Ask each bidder whether the quote includes the concrete patch and finish flooring. Many do not. If part of the run is under the house, ask about trenchless alternatives too. See how trenchless repair works for what is possible and what is not for building drains.

What are the signs that cast iron drain pipe needs replacing?

Slow drains in several fixtures, repeat clogs that cable clears and that come back, rust-coloured stains, damp spots under the floor, or a sewer smell that does not go away all point to it. Flaking and scale inside the pipe catch debris. A crack lets waste leak into the structure.

A camera is the only way to know. It shows the scaling, the cracks and the joints, and tells you whether you need a section replaced or the whole run. Our guide to a crack in cast iron drain pipe lists what you can see from outside. For a leak at a joint, see how to fix a leaking cast iron drain pipe.

Can you replace a section of cast iron with ABS or PVC?

Yes, plumbers regularly replace a failed section of cast iron with plastic pipe and connect it with approved couplings. Which plastic is allowed depends on the plumbing code and the permit for your job, so do not choose by price. Ask your contractor which material they will use and which code section applies.

Mixing materials changes noise and support: plastic is quieter than cast iron in some situations, and louder in others, and it needs hangers at the right spacing. Whole-run replacement is more consistent than a patch if the rest of the cast iron is corroded. A short patch in a long failing run just moves the leak. Our guide on cutting cast iron drain pipe explains the process.

What does it cost to replace cast iron under the house, in a wall or under a slab?

Under a house in a crawl space, the cost depends on length and access, and a short exposed section is the cheap end. In a wall, a price that includes opening and patching, which a bidder prices per job. Under a slab, national guides say $3,000 to $15,000 or more for a section with the concrete work, and more for a long run.

Concrete is the biggest variable. Replacing cast iron in concrete means cutting the slab, digging to the pipe, replacing it, and patching, and the patch is where bids differ. A trench through a slab that crosses a doorway or tile floor costs more than one under a garage floor. When quotes differ by thousands, the difference is nearly always the restoration.

Is it a DIY job, and do you need a permit?

Cutting and replacing a short exposed section is a skilled job. Cast iron is heavy, needs a proper cutter and secure couplings, and an error leaks waste into the house. Most replacements need a permit and inspection. Check with the city's building department before starting. Anything under a slab is a job for a plumber.

The California Contractors State License Board lists plumbing (C-36) as the classification for waste disposal and building plumbing. Ask for a CSLB number and check it before you sign. Nothing starts until you have a written price. Request one through our price request form.

How do you compare cast iron replacement quotes?

Compare scope. Each quote should say how many feet, where the pipe runs, what replaces it, whether the slab or wall is patched and finished, whether a permit is included, and who pays if the crew finds another failed section.

Ask for the camera footage behind the quote, and compare per-foot prices only after you have checked that both bidders are replacing the same length. See sewer line repair costs if the failure is out in the yard rather than inside the house. The home page lists the other work we arrange.

Questions people ask

How much does it cost to replace 4 inch cast iron drain pipe?

Four inch cast iron is a common size for a main drain or stack. Some national guides give $150 to $250 per foot under a slab, with the pipe itself a small share. We found no Los Angeles figure. Under a slab it runs $3,000 to $15,000 or more for a section. Size changes little; access changes a lot.

Is cast iron drain pipe worth replacing or can it be repaired?

A single crack or leaking joint can be repaired with a section replacement or a clamp. If the camera shows scale and corrosion along the run, repairing one spot only moves the failure. Replacement of the whole failing length is usually better value when the pipe is badly corroded.

Will homeowners insurance pay to replace cast iron drain pipe?

Generally not for wear and corrosion, which are treated as maintenance. If a sudden leak from a failed pipe damages the house, some policies cover the resulting damage and not the pipe. Policies differ, so ask your agent and read the exclusions.

How long does cast iron drain pipe last?

We do not have a reliable lifespan to quote. It depends on the water, the soil outside and how the pipe was used. Failing cast iron shows rust, scale and cracks on camera, and that condition tells you more than the age of the house.

Do I need to replace all my cast iron drain pipe at once?

Not always. A camera can show whether the problem is one section or the whole run. Replacing everything costs more now and avoids repeat digging. Replacing one section costs less now and may be fine if the rest is sound. Ask the plumber what the footage shows.