Not every sewer problem is in the yard. Sometimes the failing pipe is under your floor.
Written byNew Pro Plumbing·Reviewed byMiguel Lopez, Owner & Licensed Plumber, New Pro Plumbing (CSLB #974600)·Last reviewedSeptember 2026 · 8 min readQuick Answer
The building drain, the part of the sewer that runs under the house, can crack, corrode, or separate just like the lateral outside. In a raised-foundation home it's often reachable from the crawlspace; under a slab, lining from a cleanout can often avoid breaking the floor. In Marina del Rey, under-slab building drains are common, and lining is often the way to avoid breaking floors.
Inside the foundation, your home's drains come together in a building drain that carries waste out to the lateral. In older homes it's often cast iron, which corrodes and cracks with age. In a raised-foundation home, that pipe runs through the crawlspace. In a slab home, it's buried beneath the concrete. This page is part of our complete guide to sewer line repair in Marina del Rey.
Under-House Sewer Repair: Under-house sewer repair is the repair of a building's drain line beneath the home, in a crawlspace or under a slab foundation.
Crawlspace repairs are usually straightforward: we can reach the pipe and replace or repair the damaged section. Under a slab, the choice is between cutting the floor to reach the pipe and lining it from a cleanout. When the pipe qualifies, lining saves the floor.
In Marina del Rey, under-slab building drains are common, and lining is often the way to avoid breaking floors. Many Marina del Rey buildings sit on slabs, with cast-iron building drains beneath them.
We inspect the building drain from a cleanout or fixture.
We mark its position under the floor or in the crawlspace.
Direct repair in a crawlspace; lining or targeted access under a slab.
A final camera pass confirms the repaired line.
Camera first, always. Every recommendation starts with a recorded inspection you can watch yourself, and a flat-rate price you approve before we start.
Slab foundations are common under Marina del Rey buildings, with the building drain running beneath ground-floor units, garages, or lobbies. When that pipe cracks or corrodes, breaking the slab means disrupting residents and restoring finished floors. Lining is often the better answer. We camera the line, descale the cast iron, and install a liner from a cleanout. If we find a section too damaged to line, we'll locate it precisely so any concrete work is as small as possible, and we'll coordinate with management and the affected residents.
Marina del Rey is mostly condos, apartments, and townhomes built from the 1960s onward, so sewer problems here usually involve shared building lines as much as single-home laterals. Many buildings have had piecemeal repairs over the decades, so one run can mix cast iron, ABS, and PVC. We work in English or Spanish with residents, managers, and building staff.
Not sure what your line needs? We camera it first, then quote a flat rate.
Get a Free Quote| Detail | Marina del Rey |
|---|---|
| Area | Marina del Rey, CA 90292 |
| Jurisdiction | Unincorporated Los Angeles County |
| Permits | LA County Public Works Building & Safety |
| Typical access | A cleanout or fixture; targeted excavation only when needed |
| First step | Camera inspection with a copy of the recording |
| Pricing | Flat-rate, in writing, before work starts |
| Availability | 24/7, including weekends and holidays |
| License | CSLB #974600, insured |
| Languages | English and Spanish |
Marina del Rey is unincorporated Los Angeles County, so plumbing permits come from LA County Public Works Building & Safety, not LADBS. The inspector checks the new pipe, connections, and cleanouts before the job is closed, which gives your association a clean record. We schedule permit, work, and inspection tightly so residents are without service as briefly as possible.
Example scenario below is illustrative, based on common situations we see. Details vary by property; not a specific customer.
A Marina del Rey condo's ground-floor units have odors and slow drains, and the building drain runs under their slab.
We descale and line the building drain from a garage cleanout.
The floors stay intact, residents stay in their units, and the drains run freely.
New Pro Plumbing is family-owned and led by Miguel Lopez, and many Marina del Rey customers ask for him by name. Permits and inspections are part of the job, and part of the price. Our goal is simple: fix it right once, so you don't have to call us back for the same problem.
Also serving neighborhoods near Marina del Rey: Culver City, Ocean Park, Venice, Playa Vista. See all Westside service areas.
The Bottom Line
When the failing pipe is under your home, the right tools can usually fix it without major demolition: direct repair in a crawlspace, or lining under a slab.
The camera tells us exactly where the damage is. Odors inside, a damp crawlspace, or slow drains throughout can point that way. Under-house sewer work usually means the cast-iron building drain in the crawlspace or under a slab. See our cast-iron corrosion page for the wear pattern.
Often not. Crawlspace lines can be reached directly, and under-slab lines can often be lined from a cleanout. For raised-foundation homes, we access the pipe from the crawlspace and either replace the failed section or descale and line it. Lining preserves the run without cutting more pipe than needed.
Older cast iron corrodes and cracks with age. It’s worth inspecting if your home is decades old. For slab-on-grade homes, opening a slab is invasive. Lining from a cleanout is often the practical fix and avoids demo in a finished room.
Yes, if the pipe is intact enough. We descale it first, then line it. Under-house work is a plumbing permit item. We pull it through LADBS in the City of LA or LA County Public Works for unincorporated areas.
Often, yes. We descale and line the building drain from a cleanout, so ground-floor residents can stay in their units. For Marina del Rey slab-on-grade buildings, lining from a cleanout usually avoids slab demolition. See Marina del Rey trenchless hub.
This page was written by the New Pro Plumbing content team and reviewed for technical accuracy by Miguel Lopez, owner and California-licensed plumber (CSLB #974600). Agency rules are summarized from the official sources above; programs and requirements can change, so confirm current details with the agency. Nothing here is a quote. We confirm scope and pricing in writing before any work begins.
What’s new: September 2026, first publication.
Not every sewer problem is in the yard. Sometimes the failing pipe is under your floor.
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