Under-slab tunneling & access excavation · San Antonio & Austin
Under-Slab Tunneling & Access Excavation
Motmot provides under-slab tunneling and access excavation for licensed plumbers, foundation repair projects, engineers, property managers, and homeowners who need repairs completed without unnecessary interior slab demolition. We dig it and back-fill it; your licensed trade does the repair.
The cleanest way to reach what's under a slab
Under-slab tunneling and access excavation for plumbing, foundation, and structural repairs.
When a sewer line, a slab leak, an interior pier, or an engineer's evaluation sits under a concrete slab, there are two ways in: break the finished floor from inside, or tunnel under it from outside. Tunneling keeps the floors whole, lets the household or business stay put, and avoids the concrete-and-flooring restoration that interior breakout always brings. It's the approach that makes sense on most finished homes and occupied buildings across Central Texas.
Motmot sells the access, not the licensed pipe work. We come out of foundation repair, so we know how a line runs under a Central Texas slab, how deep an interior pier needs to go, and how much room a plumber needs to actually work. That's why our tunnels are something a crew can work in — not just a hole in the ground.
What we dig
Five under-slab tunneling services.
Plumbing tunnel excavation
Access tunnels and trenches so a licensed plumber can replace a sewer line, drain line, water line, or cast iron under your slab — without jackhammering your floors.
Learn more →02Foundation repair tunneling
Interior pier access and engineer-access tunnels so piers go in and plumbing is protected — without breaking the slab from inside the house.
Learn more →03Engineer access tunnels
Clean, shored access so a structural engineer can observe grade beams, plumbing penetrations, voids, moisture, and soil under the slab.
Learn more →04Commercial under-slab access
Low-disruption tunneling under restaurants, clinics, schools, and retail so business keeps running while plumbing or structural work happens below.
Learn more →05Tunnel backfill & cleanup
After the repair: backfill placed and compacted in lifts, the site restored, spoil hauled, and the work documented — the part a lot of diggers skip.
Learn more →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 under a slab actually runs, where the belly usually hides, and how much room a plumber needs to set a fitting, swing a saw, and lie comfortably to make a joint. We open the work area wider where the repair is, shore it, keep it dry, and light it — then get out of the way. The plumber shows up to a tunnel they can work in, not a hole they have to fight. That's the difference between a bore dug by people who've only moved dirt and one dug by a foundation crew who has watched the pipe work happen a hundred times.
- We open the work area wider where the repair is — 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
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 a plumbing or foundation job. We staff the bore to the schedule, dig in clean shifts, and hand the plumber an open, ready trench so their billable hours aren't spent waiting on a shovel.
Precision
We dig to the plan — depth, width, and pitch shot before the first spade, then verified as we go. The pipe run, the pier location, or the engineer's access point lands where the drawing says it should, the first time.
OSHA safety
Tunneling and trenching carry real cave-in exposure. 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: width to work in, clean floor and walls, true pitch, and a documented hand-off. Backfill is placed and compacted in lifts so the ground — and anything on it — settles right.
Standards & compliance
Texas 811 is called and lines are located before we dig. We sell the access, not the licensed pipe work — your plumber stays the plumber. Permits, locates, and clean documentation come standard.
Who we tunnel for
Ten markets. One under-slab access partner.
Plumbing and foundation repair are the core — but anyone who needs to reach work under a slab without tearing up the floor is who we dig for.
Plumbing companies
Under-slab tunneling for plumbers.
See plumbing companies tunneling →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 →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 to your licensed plumber, foundation crew, or engineer — open, dry, and workable.
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 — Tradesman, Journeyman, Master, and Inspector licenses. Motmot sells under-slab tunneling and access excavation; we partner with your licensed plumber for the pipe repair itself. And before any dig, Texas 811 is contacted at least two business days ahead so gas, water, and utility lines are located first.
Tunneling FAQ
Under-slab tunneling questions, answered straight.
From real jobs
Under-slab access, dug and documented.
Tunnels, access pits, exposed pipe and piers, and clean backfill — from real Central Texas jobs.
Need access under a slab? Tell us the run.
Plumber, GC, property manager, or homeowner — we'll scope the tunnel, dig it to plan, and back-fill it clean. Your licensed trade does the repair.
Now booking free inspections in Central Texas.