Cast Iron Drain Replacement in Oregon
Cast iron drains rot from the bottom of the pipe upwards, where you cannot see them. By the time there is a smell or a stain, the invert has usually been gone for years.
Camera assessment before any quote. Stacks, horizontals and under-slab runs.
How cast iron drains fail
Cast iron was the standard drainage material in American construction from the nineteenth century through to the 1970s, and it is in the walls and under the floors of a great deal of Oregon housing. It is heavy, quiet and genuinely durable, a well-installed cast iron system can run seventy years or more.
What kills it is not water but what happens above the waterline. Waste flowing along the bottom of a horizontal drain protects that surface to a degree. The exposed upper interior, in contact with warm, humid sewer gas containing hydrogen sulphide, corrodes steadily. Bacteria convert the sulphide to sulphuric acid on the pipe surface, and the metal is eaten away.
The result is a characteristic and counter-intuitive failure pattern. In vertical stacks the pipe thins generally. In horizontal runs, the top and sides go first, and eventually the invert, the bottom channel, rots out too, at which point waste is running through a trough of rust and soil rather than a pipe. Externally it can still look like a pipe. That is why a visual inspection of a cast iron horizontal is close to worthless and a camera is essential.
Scale is the other half of the problem. The corrosion products build inwards, roughening the bore, catching solids and reducing capacity long before perforation. A four-inch cast iron drain can have a two-inch effective passage.
What the symptoms look like
Recurring slow drains and blockages across multiple fixtures, especially where the rough interior is catching paper and solids. Cabling clears it and it returns, because the roughness is permanent.
Sewer smell with no visible leak. Gas escaping through a perforation inside a wall or under a floor has to go somewhere, and it usually surfaces as an intermittent smell that nobody can locate.
Staining and damp at the base of a wall containing a stack, on a basement ceiling, or on a slab floor. Often mistaken for a supply leak, but the timing gives it away: a drain leak only appears when something upstream is used.
Rust flakes in a floor drain or at a cleanout, and orange staining around a cleanout cap.
Insects and rodent activity around a slab or crawl space, which follows a failed drain reliably.
Settlement or a soft spot in a slab floor, which means water has been washing soil out from under it for some time. That is the serious one.
Sewer smell with no visible leak usually means a failed invert.
Call Now: 1-866-203-6890Assessing what you actually have
A camera goes into the drainage system before we quote anything. In cast iron the inspection answers questions that determine cost by an order of magnitude.
How much of the system is cast iron, and where does it transition to something else, many Oregon houses have had partial replacement already. What is the wall condition along the runs: general scaling, localised perforation, or invert loss. Is the horizontal run holding its line and fall, or has settlement created a belly. Where exactly are the failures, in feet from access and, for under-slab runs, located and marked on the floor above.
We look at the whole system rather than the failed section, because the rest of it is the same age and the same environment. Quoting the replacement of one perforated horizontal in a house where the stack is equally far gone helps nobody.
You see the footage and keep it. If the answer is that the system has years left and needs cleaning rather than replacing, that is a legitimate outcome and we are glad to report it.
Stacks, horizontals and under-slab
Vertical stacks run inside walls, usually from the fixtures down to the horizontal drain, and continue up as the vent. Replacement means opening the wall along the run, often in a bathroom, sometimes across two floors. It is disruptive but predictable, and the work itself is straightforward.
Horizontal runs in a crawl space or basement are the easiest cast iron to replace, because access is already there. If your house has a crawl space, this is the good news in an otherwise expensive job.
Under-slab drainage is the difficult case. The pipe is cast in or beneath a concrete floor, and replacement means cutting the slab, excavating, replacing the pipe, backfilling, and repouring. Located camera work is what keeps that cut to a targeted trench instead of a demolition. On some layouts, rerouting the drainage overhead or around the outside of the building is cheaper and less destructive than cutting a long path through the slab, and we will price that comparison where it applies.
A camera in the stack answers this in an hour.
Book a Camera InspectionRepair, line or replace
Spot repair, cutting out a failed section and joining new pipe with proper couplings, is reasonable where the failure is localised and the camera shows the rest of the system in genuinely sound condition. That combination is less common in cast iron than in sewer laterals, because the whole system has been exposed to the same conditions for the same length of time.
Lining is possible on cast iron drains and is worth considering for under-slab runs specifically, where the alternative is cutting concrete. A cured liner needs a host pipe that still holds its shape and its line; a run that has lost its invert entirely may not qualify, and one with a belly will keep the belly. Descaling to a clean wall first is essential and is a real part of the cost.
Replacement in PVC is the definitive answer and what we recommend for most accessible runs and stacks. Smooth-bored, immune to the corrosion mechanism that killed the original, and lighter to work with. Where noise transmission through a stack matters, a bathroom above a living room, or a multi-unit building, heavier-wall PVC or a sound-insulating wrap addresses the one respect in which cast iron was better.
How replacement runs
Camera assessment and location first, with under-slab runs marked on the floor. Then a written scope: which sections, by what method, what gets opened, and what restoration is included.
The work itself is sequenced to keep the house usable. Cast iron is cut out in sections rather than dropped in one piece, a full stack is extremely heavy and the demolition has to be controlled. New PVC goes in at correct fall, with proper support and with cleanouts fitted where the old system had none.
Slab work adds a stage: saw-cut, break out, excavate, replace, bed and backfill in compacted lifts, then repour to match the existing floor level. We tell you plainly that a slab patch is visible unless the whole floor is being refinished.
Inspection before anything is closed up, then drywall or floor restoration to the standard in the quote. A stack replacement in one bathroom is typically two to three days; a whole-house cast iron replacement including under-slab work can run one to two weeks.
What drives the cost
Access, overwhelmingly. Horizontal runs in an open crawl space are at the low end. Stacks inside finished walls are mid-range. Under-slab drainage is the high end, and the length of slab that has to be cut is the single biggest variable in the whole job.
After that: the extent of the system, how much is genuinely failed versus merely old, whether rerouting can avoid slab work, and the restoration standard, drywall, tile, flooring and concrete finishing all sit in that line.
The one big saving available is timing. If the house is being remodelled, or a bathroom is coming out anyway, doing the drainage in that window removes most of the access cost. If a remodel is on your horizon at all, get the drains scoped before you plan it.
Doing it with the walls open for other work costs far less.
See Replacement OptionsServices that often go with this one
- Whole-home repiping
- Galvanized pipe replacement
- Sewer line repair
- Drain cleaning
- Hydro jetting
- Basement water leak diagnosis
Where we cover
Available in all seven regions, 155 Oregon communities.
Cast iron drains, answered
Commonly fifty to eighty years depending on the waste stream, ventilation and installation quality. Most cast iron still in Oregon houses is inside or past that window, which is why we assess the whole system rather than the one section that failed.
Sometimes, and it is most attractive under a slab where the alternative is cutting concrete. It needs a host pipe that still holds its shape, and descaling to a clean wall first. A run that has lost its invert or developed a belly is not a lining candidate.
A located camera inspection marks the failure position and depth on the floor above. Symptoms that point that way include damp or a soft spot in the slab, sewer smell with no visible source, and blockages affecting only ground-floor fixtures.
Sewer gas is unpleasant and, in enclosed spaces at concentration, genuinely hazardous. An intermittent smell in a living space with no visible leak should be investigated rather than masked, it usually means a perforation venting inside a wall or under a floor.
If both are at the end of their life and the walls are going to be open, yes, access is the expensive part and you pay for it once. We assess both during the walkthrough and will tell you if only one genuinely needs doing.
Marginally, on a stack passing a living space, cast iron is genuinely quieter. Heavier-wall PVC or a sound-insulating wrap on the exposed run resolves it, and we specify that where the stack passes somewhere it matters.
We scope the whole system, not just the failed section.
Ask About Your StackYou cannot judge cast iron from the outside
A camera in the stack and the horizontals tells you what is left of the pipe wall. Then the decision is between cleaning, lining and replacing, on evidence rather than age.
Statewide, including older housing across the valley.
Call 1-866-203-6890