San Antonio · Bexar County
Sewer Line Repair in San Antonio, TX
San Antonio homes built from the 1950s to the 1970s often have cast-iron drain lines under the slab that are now cracking and backing up. A camera inspection and a hydrostatic test show how much of the system has failed, which decides between a sectional repair and replacing the under-slab drains.
- Independent local pros
- Free referral, no obligation
- You approve the price before work starts
What is different about sewer line repair in San Antonio?
Cast iron corrodes from the inside, and under a slab the bottom of the pipe goes first. Early signs are slow drains throughout the house, backups that return soon after cleaning and a sewer smell. Because the leaking water wets the clay beneath the house unevenly, floor cracks or sticking doors sometimes appear too.
Outside the house, the yard line to the city connection can be a different material and in different condition, so ask for it to be inspected separately. Repairs under the slab are reached by tunneling or through the floor, and the work is permitted by the city's Development Services Department inside San Antonio. Nearby cities such as Alamo Heights and Schertz issue their own permits.
From the San Antonio plumbing guide
Cast-iron drains in older homes
Homes from the 1950s to 1970s often have cast-iron drains under the slab that are now cracking and backing up.
What to check and ask before work starts in San Antonio
- Ask for the camera video and the hydrostatic test result in writing
- Ask whether the yard line was inspected as well as the under-slab drains
- Ask which sections must be replaced now and which can wait
- Ask how tunnel backfill will be handled
Licensing and permits for sewer line repair in San Antonio
Plumbers in Texas are licensed by the Texas State Board of Plumbing Examiners. In San Antonio, plumbing permits are issued by the city's Development Services Department; nearby cities such as Alamo Heights and Schertz issue their own.
Keystream Plumbing is a referral service. We do not perform plumbing work or hold a contractor license. The independent plumber you are connected with is responsible for licensing, permits and the work itself.
What the job usually involves
The steps are the same in San Antonio as anywhere; the local conditions above change how each one is done.
- Clear and camera
- Locate and mark
- Choose the method
- Permit, repair and inspect
Sewer Line Repair questions from San Antonio
How long do cast-iron drain pipes last under a slab?
There is no fixed figure, but many under-slab cast-iron systems show serious corrosion after 50 to 70 years, and soil and water conditions change that. A camera inspection is the only way to know the condition of yours.
Can cast-iron drains be lined instead of replaced?
Sometimes. Lining needs a pipe that still holds its shape and can be cleaned to bare metal. Pipe with missing sections or a collapsed bottom usually has to be replaced. A plumber should show you the footage that supports the recommendation.
Sources
- Water quality and water sources, San Antonio Water System
- License search and consumer information, Texas State Board of Plumbing Examiners
- Hardness of water, US Geological Survey
Local information reviewed October 1, 2026. Rules and programs change; confirm details with the agency before you rely on them.
More plumbing help in San Antonio
Sewer Line Repair in other cities
Ownership rules, soil, water and pipe materials make this a different job from one city to the next.
Related guides: Main Sewer Line Clog: Signs and What to Do, When to Call an Emergency Plumber (and When It Can Wait).
Need sewer line repair in San Antonio?
Call (833) 520-4758. Same-day service is often available; call to check timing.