Cast Iron Drain Line Replacement in Plano, TX
Responsible Master Plumber Bradley Earp, M-43562 · $97 diagnostic · under-slab tunneling at $425/ft · financing available · 15% off same-day approval
If your Plano home was built before the mid-1980s, there's a good chance its drains under the slab are cast iron. Cast iron fails from the inside: scale narrows it, then the bottom of the pipe rots out. We replace those drain lines with PVC by tunneling under the foundation, so your floors stay where they are.
- Licensed & Insured (TSBPE M-43562, Responsible Master Plumber Bradley Earp)
- $97 Diagnostic
- Upfront Pricing
- Certified Price Review
- ★ 4.8 on Google
Which Plano homes have cast iron drains
Plano's subdivisions went in decade by decade, and the drain pipe changed with them. Cast iron was the standard for drains under slab homes through the 1960s and 1970s, and plastic took over during the late 1970s and 1980s (general trade history; your camera footage is what counts).
- Old Towne (1947–1970), Haggard Addition (1952–1970), Belle View Estates (1958–1965), North Forest Estates (1962–1963), Briarwood (1962–1973). Cast iron under the slab is expected.
- Dallas North Estates (platted 1970–1975, essentially built out by 1988). Most homes are original cast iron under the house.
- Park Forest, Los Rios and other 1970s–early 1980s neighborhoods. Often cast iron; some are mixed or early ABS.
- Late 1980s and newer. Usually PVC or ABS. If you're not sure, a camera answers it in about 30 minutes.
Plano still has more than 22,000 homes built before 1980 (third-party estimate from census data).
How cast iron fails under a slab
- Scale and tuberculation. Rust builds up inside, the pipe narrows, and paper catches. Repeated clogs in the same drain are the first sign.
- Channeling. The bottom of the pipe erodes along its length until it's open to the soil. Water leaks into the clay under your house, which can feed foundation movement.
- Cracks and separated joints. Clay soil movement and old joints pull apart. Roots and sewer gas get in.
- Signs to watch for: recurring clogs, slow tubs and showers, sewer smell, gurgling, cracked tile or a sudden foundation shift, and drain-line leaks found by a plumbing test.
Full replacement vs. spot repair
If the camera shows one localized break, a spot repair through a single access hole can be right, and we'll tell you so. If it shows scale and channeling along most of the run, spot repairs just move you from one access hole to the next at $1,150 each. Replacing the whole under-slab run at once is usually cheaper over the life of the house. We show you the footage and the price both ways.
How we replace cast iron under a Plano slab
- Camera and map. We camera every branch and mark where each bathroom group and the kitchen tie into the main.
- Plan the tunnels. We size the tunnels to reach every branch you need replaced. Many homes need one main tunnel and one or two short laterals to bathroom groups.
- Tunnel from outside. Hand-dug tunnels under the foundation, so cabinets, tile and flooring stay in place. Nothing inside the house is moved except for occasional toilet pulls.
- Replace with PVC. New drain line, new connections at every fixture group, and a two-way cleanout outside.
- Test and inspect. Water test, City of Plano inspection, then backfill and compaction in lifts to support the slab.
We replace failing cast iron by tunneling under the slab, so floors stay intact. Where a yard section is still round and the route is open, trenchless pipe bursting can replace it without a full-length trench.
Cast iron, slab leaks and your foundation
A channeled cast iron drain can leak for years before you see it. If you're having foundation work done, have the drains tested and cameraed first; lifting a slab can crack old cast iron. If a slab leak is on the water (supply) side instead, see slab leak repair in Plano.
Cast iron pipe replacement cost in Plano
Cast iron replacement uses the same published prices as our sewer work:
Example (illustration only): a 1970s two-bath Plano ranch with 55 feet of tunnel to reach both bathroom groups and the kitchen, 2 access holes and 20 feet of yard line: 55 × $425 + 2 × $1,150 + 20 × $180 = $29,275, or $24,883.75 approved same day.
Pick the floor plan closest to yours in the sewer line cost calculator; it prices the tunnels, holes and trench for that layout.
Start with a $97 diagnostic
Every job starts with a $97 diagnostic, a camera inspection or walk-through as needed, and a written quote before work begins. We’re open Monday through Saturday and closed Sunday.
Already have another quote? Send it to us.
Certified Price Review: We’ll match or beat apples-to-apples plumbing scopes. Send us a written, itemized cast iron replacement estimate from another licensed plumber. We compare scope, installation method, materials, access/excavation, warranty and diagnostics. If the work is directly comparable, we may adjust our price. Verbal or incomplete estimates may not qualify, and a review doesn’t obligate us to match. See program terms →
Financing: Larger jobs like sewer replacement and repipes can be split into monthly payments, subject to credit approval. See financing options →
Save 15% when you approve the same day. Approve your written quote the day we give it to you and we take 15% off.
Plano cast iron pipe replacement FAQs
How much does it cost to replace cast iron pipes under a slab in Plano?
We charge $425 per foot to tunnel under the slab, $180 per foot to trench outside and $1,150 per access hole. A typical two-bath ranch runs in the low-to-mid $20,000s before the 15% same-day discount; your camera inspection sets the exact footage.
How do I know if my Plano house has cast iron drains?
Homes built before about the mid-1980s often do. Look at the vent pipes in the attic or garage, or the cleanout outside: heavy black metal is cast iron. A camera inspection confirms it and shows the condition.
Do you have to jackhammer my floors?
No, in most homes. We tunnel under the foundation from outside, so tile, cabinets and flooring stay in place.
Can I just replace the bad section?
Sometimes. If the camera shows one localized failure, a spot repair can make sense. If the scale and channeling run the whole line, a full replacement is usually cheaper than repeated access holes.
Will replacing cast iron affect my foundation?
Done right, no. We backfill and compact the tunnels in lifts to support the slab. Leaking cast iron, on the other hand, can soften the soil under your foundation.
Does insurance pay for cast iron replacement?
Usually not for wear and age, though some policies cover resulting water damage or access costs. Ask your insurer; we'll provide camera video and an itemized quote.