01Available
Tunnel Excavation
Hand-tunneling beneath slab foundations to access failed sewer and water lines without breaking interior concrete.
Licensed & InsuredMaster Plumber · TX24/7 Emergency Service
SAN ANTONIO'STUNNEL & PLUMBINGSPECIALISTS
Under-Slab Repairs · Sewer Line Replacement · Camera Inspections
✓Licensed & Insured
✓Master Plumber on Staff
✓10+ Years Experience
✓Bilingual Service
Expert tunnel excavation, sewer line replacement, slab leak repair, water line repipes and commercial plumbing services throughout Texas.
Tunnel ExcavationUnder-Slab RepairsSlab Leak DetectionSewer Line ReplacementSewer Camera InspectionHydrostatic TestingRepipesTrenching
01 · Signature Service
Specialists in tunnel excavation for under-slab plumbing repairs.
When a sewer lateral, drain line or hot-water line fails beneath a concrete slab, the cheapest-looking fix — breaking up the slab inside the house — usually causes the most damage. We hand-tunnel from the exterior to reach the failed pipe, complete the repair, run a camera and hydrostatic test to verify, then backfill in lifts and compact. Your floors, tile and foundation stay intact.
- Cast iron sewer line replacement under slabs
- Copper, CPVC and PEX water-line repairs
- Spot repairs, tie-ins and full re-routes
- Hand-tunneling preserves interior finishes
- Permit-ready: pre- and post-repair hydrostatic test
- Engineered backfill with proper compaction
02 · Capabilities
Specialist services for complex under-slab work.
We focus on the jobs most plumbers won't touch — tunneling, under-slab repairs, sewer replacement and camera-verified diagnostics. Licensed, insured and Master Plumber qualified.
02Available
Under-Slab Pipe Repair
Replacement and spot repair of cast iron, PVC, copper and PEX lines running beneath concrete slabs.
03Available
Sewer Line Replacement
Full or partial replacement of main sewer laterals and yard lines with proper fall, cleanouts and code compliance.
04Available
Sewer Camera Inspection
Color push-camera inspection with on-screen locating to pinpoint blockages, breaks, bellies and root intrusion.
05Available
Hydrostatic & Static Leak Testing
Isolation testing of drain, waste and vent systems to confirm leaks before and after under-slab repairs.
06Available
Slab Leak Detection & Repair
Acoustic and pressure-based leak isolation on pressurized water lines, repaired by re-route or tunnel access.
07Available
Trenching & Yard Excavation
Open-cut trenching for sewer laterals, water service lines and yard line replacements with clean restoration.
08Available
Rough-In
Full repipes in PEX-A or Type-L copper, including manifold installs and pressure testing to local code.
09Available
Sewer & Drain Line Repair
Repair or replace cracked, offset, root-intruded or back-pitched DWV piping — built to code for long-term flow.
10Available
Water Heater Install & Repair
Tank and tankless installs, T&P valves, expansion tanks, gas and electric — sized to fixture demand.
11Available
Residential Specialist Work
Slab leaks, under-slab repairs, repipes, camera inspections and emergency response for homeowners.
12Available
Commercial Plumbing
Multi-tenant, retail and small-industrial coordination — backflow, grease interceptors, repipes and tunnel work.
03 · How we work
A clear, professional process — start to finish.
01
Call or message
Reach us by phone or WhatsApp. We respond fast — usually same day.
02
Inspection & diagnosis
On-site assessment with camera inspection and hydrostatic testing when needed.
03
Transparent quote
Scope, materials and written estimate before any work begins.
04
Clean professional repair
Code-compliant repair, post-repair verification, photo documentation.
05 · Diagnostics
Sewer & drain camera inspection.
Before we recommend a single repair, we look. A push-camera with on-screen locating shows exactly what is happening inside your DWV system — offsets, bellies, root intrusion, channeling in cast iron, collapsed sections — so the scope of work is based on evidence, not guesswork.
- Locate breaks & bellies
- Find root intrusion
- Verify line slope
- Map sewer lateral path
- Document with video
- Plan exact tunnel route
06 · Slab leaks
Slab leak detection & repair.
A spike in your water bill, a warm spot on the floor, low pressure, the sound of running water with every fixture off — these are pressurized slab-leak symptoms. We isolate the leak with pressure tests and acoustic equipment, then repair by spot tunnel access or full re-route, depending on pipe condition.
Higher-than-normal water bills
Warm or damp areas on the floor
Low water pressure
Sound of running water at the meter
Cracks or moisture in flooring
Mildew or musty smell near slab
07 · Why MG
Why homeowners & businesses choose MG Building Maintenance.
Tunnel & under-slab specialists
Capability most plumbers don't offer in-house.
Master Plumber licensed
Qualified to pull permits and pass TX inspections.
Licensed & insured
Full coverage on every job, every time.
Camera-verified diagnosis
Repairs scoped from evidence, not guesswork.
Honest, transparent estimates
Written quotes — no upsell, no surprises.
Bilingual EN · ES
Clear communication with every customer.
Clean job sites
Containment, dust control, full restoration.
Trusted by industry
Realtors, engineers, architects, GCs.
09 · Service areas
Proudly serving San Antonio & surrounding Texas communities.
San Antonio
Headquarters
Converse
Service area
Schertz
Service area
Cibolo
Service area
Universal City
Service area
Live Oak
Service area
Selma
Service area
Boerne
Service area
New Braunfels
Service area
Austin
Service area
Houston
Service area
Dallas
Service area
24/7 response
Plumbing emergency? Call MG now.
Active slab leaks, sewer backups, broken yard lines, under-slab pipe failures — we dispatch fast in San Antonio and surrounding areas for high-priority specialist work.
10 · FAQ
Answers to common questions.
Don't see your question? Call 210-956-0227 or message us on WhatsApp.
What is tunnel excavation for plumbing repairs?+
Tunnel excavation is hand-digging a tunnel from outside the foundation in under the slab so we can reach and repair failed sewer or water lines without breaking up the interior concrete, tile or flooring. It typically saves significant restoration cost on slab-on-grade homes.
Do you offer emergency plumbing service?+
Yes — we provide 24/7 emergency response for active leaks, sewer backups, slab leaks, hot-water failures and other time-sensitive plumbing problems in San Antonio and surrounding areas.
Are you licensed and insured?+
Yes. MG Building Maintenance operates under a Texas Master Plumber license and carries full liability and workers' compensation insurance. We pull permits and pass inspections.
Do you repair slab leaks?+
Yes. We isolate slab leaks with pressure testing and acoustic equipment, then repair by spot tunnel access, in-slab repair or full re-route depending on pipe condition and material.
Do you offer sewer camera inspections?+
Yes. We run color push-cameras with on-screen locating to verify breaks, bellies, root intrusion and offsets before recommending any repair scope.
What about hydrostatic testing?+
We perform pre- and post-repair static / hydrostatic tests on DWV systems to isolate leaks and verify the repair before backfill — required for many real-estate inspections in Texas.
Do you offer free estimates?+
Yes, free estimates are available for most major projects including tunneling, repipes, under-slab work and water heater replacements. Contact us to schedule a consultation.
How do I get started?+
Simply call or message us. We will discuss your project, answer your questions and schedule an on-site assessment to provide a detailed written quote.
What areas do you serve?+
San Antonio, Converse, Schertz, Cibolo, Universal City, Live Oak, Selma, Boerne, New Braunfels and surrounding Texas areas. Larger projects considered in Austin, Houston and Dallas.
Do you speak Spanish?+
Sí. Hablamos español — atendemos a clientes residenciales y comerciales en inglés y español.
Do you install and repair water heaters?+
Yes — tank and tankless, gas and electric, including expansion tanks, T&P valves and proper venting / gas sizing.
11 · Contact
Let's get your plumbing solved.
Fastest response is by phone or WhatsApp. For a written estimate, send us a few details and we'll follow up the same day.