For plumbing companies · Subcontract the excavation
Under-Slab Tunneling for Plumbers in San Antonio & Austin
Broken sewer line, slab leak, belly in the drain, full cast-iron replacement. The pipe work is the part your crew is fast at. The digging is what eats the day and ties up a journeyman. We dig the access, you make the licensed repair, and the trench is sized to be worked in.
Most plumbing companies don't want to hand-tunnel under a slab, and they shouldn't have to. Every hour a journeyman spends on a shovel is an hour nobody bills pipe work for. We're the dig partner. You keep the customer and the licensed repair, we open and close the ground. We come out of foundation repair, so we already know how the line runs under a Central Texas slab and how much room you need to make a joint. The spoil is our problem, and the bore stays open only as long as your repair needs it.
When you call us
The jobs that need a tunnel.
Broken or collapsed sewer line
The camera puts the failure mid-run, not at the cleanout. We tunnel in from the exterior to the break so your crew replaces pipe instead of hunting it room by room.
Cast-iron replacement
Sixty-year-old cast iron is scaling shut house-wide. We open a tunnel along the main run so you re-pipe in continuous lengths with room to slope it correctly, rather than in jackhammered pits.
Slab leak on the supply side
A hot or cold line needs a reroute or a spot repair. We expose the line and keep the bore dry before you cut in.
Belly or back-pitch in the drain
A hydrostatic test or camera shows standing water in a low spot. We tunnel the affected run so you can re-lay it to grade.
Spoil with nowhere to go
A tight lot still has to hold the dirt that comes out of the bore. We stage it back from the edge and clear of your work area, then haul it off when the tunnel closes.
No interior demolition wanted
The homeowner can't lose tile, hardwood, or a remodeled bath. Tunneling from outside keeps the floor whole, which is a line you can put straight on the bid.
What you get
How we work with you.
A badly dug bore costs you real hours. Too narrow to turn in. No fall to the floor, so it pools. Spoil stacked where your saw has to go, and nothing holding the walls. We size the tunnel to the repair, widen it at the fitting, shore the walls, and run light to the face. Spoil is staged clear of where your crew works. You get the trench on the day we said, do the pipe work, and call us back to backfill in compacted lifts once it passes test. That is the whole time it sits open. Nobody on our crew touches the pipe, and nobody on our crew talks to your customer about anything but dirt.
SCOPE OF WORK
- Exterior or interior tunnel dug to your pipe run, depth, and pitch
- Bore widened and shored where the fitting goes
- Spoil staged clear of your work area, then hauled off
- Trench kept dry and lit, and open only through your repair
- Texas 811 locates called before the dig
- Backfill and compaction in lifts once the repair passes test
How every bore is held
Velocity, precision, OSHA, quality control, and the standards behind them.
Tunneling is the slow, risky part of a plumbing or foundation job. We run it like a discipline, not a dig.
Velocity
Hand-tunneling is the slow part of any plumbing or foundation job. We staff the bore to the schedule and hand over an open, ready trench instead of billable hours spent waiting on a shovel.
Precision
We dig to the plan. Depth, width and pitch are shot before the first spade and verified as we go, so the pipe run or the pier lands where the drawing says.
OSHA safety
Cave-in exposure is real. We work to OSHA Subpart P excavation practice: protective systems, safe access and egress, spoil set back from the edge, water and air managed, and daily competent-person inspection.
Quality control
Every bore is checked against the drawing for working width, clean floor and walls, and true pitch. Backfill goes in compacted lifts so the ground above settles right.
Standards & compliance
Texas 811 is called and lines are located before we dig. We sell the access, not the licensed pipe work. Permits, locates and clean documentation come standard.
Why a foundation crew digs a better tunnel
We come out of foundation repair, and we've dug alongside plumbers for years, so we know how to dig it.
We know how a sewer line runs under a slab, where the belly usually hides, and how much room it takes to set a fitting and lie down to make a joint. So we open the bore wider at the repair, shore it, keep it dry, light it, and get out of the way. Years of watching the pipe work happen is what tells us how wide to make it.
- We open the work area wider where the repair is, leaving room to set, slope, and joint
- Shored, dry, and lit so the plumber works in a tunnel, not a hole
- We dig it and back-fill it; your licensed plumber does the pipe work
From locate to backfill
How an under-slab tunnel runs.
Locate & plan
We call Texas 811, locate utilities, and shoot the depth, width, and pitch the repair needs before a spade hits the ground.
Open the entry
A compact entry pit goes in at the chosen point, usually outside the foundation, so the floors above stay whole.
Tunnel to the work
We hand-tunnel to the pipe run, pier location, or access point, widening the bore where the repair happens.
Shore & hand off
The bore is shored and inspected, then handed off open, dry, and workable to your licensed plumber, foundation crew, or engineer.
Backfill in lifts
Once the repair passes, we place backfill in compacted lifts so the slab, drive, or walk above settles correctly.
Clean & document
Spoil hauled, site restored, and the access and backfill documented for your file or warranty.
LICENSING & SAFE DIGGING
In Texas, plumbing repairs are regulated by the Texas State Board of Plumbing Examiners, which issues Tradesman, Journeyman, Master, and Inspector licenses. Motmot sells under-slab tunneling and access excavation, and partners with your licensed plumber for the pipe repair. Before any dig, Texas 811 is contacted at least two business days ahead so gas, water, and utility lines are located first.
SAN ANTONIO PERMITTING · IB176
When a plumbing tunnel runs under a San Antonio foundation, the city's Information Bulletin 176 sets the rules, and they match how we already work. A qualified design professional evaluates the structural condition of the foundation over the excavation, and your plumbing company notifies the city plumbing inspector. City inspectors will not enter the tunnel, so the plumbing company supplies a fiber-optic camera, two-way communication, and adequate staffing, and the tunnel is sized, lit, and ventilated for a safe inspection. The pipe repair is performed by a plumber licensed by the Texas State Board of Plumbing Examiners under a city plumbing permit, and a design professional's letter goes to the city before backfill. We dig the access to that standard and keep it safe to inspect; you do the licensed pipe work; the engineer and the city sign off.
Industry FAQ
Plumbing companies tunneling, questions answered.
From real jobs
What this access looks like on real jobs.
Tunneling for other industries
Foundation repair
Foundation repair tunneling.
See foundation repair tunneling →Structural engineers
Engineer-access excavation for under-slab evaluations.
See structural engineers tunneling →GCs & remodelers
Under-slab access for remodel plumbing.
See gcs & remodelers tunneling →Property mgmt & multifamily
Low-disruption under-slab tunnel access for rental and multifamily properties.
See property mgmt & multifamily tunneling →Investors & flippers
Pre-sale and investor property tunneling for plumbing/foundation access.
See investors & flippers tunneling →Realtors & inspectors
Under-slab access for repair work before closing.
See realtors & inspectors tunneling →Restoration & insurance
Access excavation for slab leak and water-damage repairs.
See restoration & insurance tunneling →Commercial facilities
Commercial under-slab tunneling for plumbing and structural access.
See commercial facilities tunneling →Backfill & cleanup
Tunnel backfill and cleanup.
See backfill & cleanup tunneling →Need under-slab access? Tell us the run.
We'll scope the tunnel, dig it to plan, shore it, and back-fill it clean, so your licensed repair goes in smoothly and the floors above stay whole.
Now booking free inspections in Central Texas.