For general contractors & remodelers

Under-Slab Access for Remodel & GC Plumbing Changes

Moving a bathroom, relocating a kitchen island, or adding a laundry drain under an existing slab means new plumbing where there is no access. We tunnel to the runs your plumber needs, on the date your rough-in is scheduled, so the sequence behind it doesn't slide.

Get a Tunneling Quote (210) 816-0034

A trench-tunnel opened under a stem wall to reach a plumbing run for a remodel.

On a remodel the schedule is the thing that gets wrecked, and an under-slab surprise wrecks it in both directions. The plumber can't rough in, and the tile crew behind him can't start. We're the trade that opens the ground on a date you can put in the schedule. Tell us where the new fixtures land and we tunnel to the runs, then come back after the inspection passes and leave a subgrade your slab patch can sit on. Same measure-first discipline we bring to foundation work, fitted to your build sequence.

“Under-slab access for remodel plumbing”“Tunnel excavation for slab plumbing modifications”“Access excavation coordinated with your build schedule”

When you call us

The jobs that need a tunnel.

Relocating a bathroom or kitchen

New fixtures mean new drains where the slab has none. We tunnel the access so your plumber lays the lines without demoing the finished floor.

Adding a laundry or wet bar

A new drain and supply under an existing slab needs a path. We dig it to the fixture location on the plan.

Commercial tenant build-outs

A restaurant kitchen or a tenant fit-out needs floor drains and grease lines below an existing slab. We open the runs to plan.

Preserving expensive finishes

Polished concrete, imported tile, or wide-plank wood you can't cut and rematch. A controlled entry keeps the field intact.

The rough-in date can't move

Your plumber, the inspector, and the backfill all have to land in order. We sequence the dig into that order rather than around it.

What you get

How we work with you.

We work like a sub who has read the plan. The access is coordinated with your plumber's rough-in, the entry is controlled and the dust kept down, and backfill goes in compacted lifts so whatever lands on top later, a slab patch or new cabinets, sits on ground that will hold. Because we understand foundations, we flag it early if a planned dig runs near a grade beam or a bearing point that needs respect. On a remodel the dig price matters less than the day the access is open. Get that date pinned before you take the bid, from us or from anyone else.

SCOPE OF WORK

Tunnels and trenches dug to your new fixture and drain locations
Access coordinated with your plumber's rough-in and the inspection
Controlled entry, dust managed, finishes protected
Backfill and compaction in lifts for whatever's placed above
Foundation-aware digging near grade beams and bearing points

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.

VEL

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.

PRC

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.

SAF

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.

STD

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.

Industry FAQ

GCs & remodelers tunneling, questions answered.

Can you reach a drain without cutting our new floor?

Usually, yes. Most under-slab runs can be reached from a controlled entry, often outside the foundation or from an unfinished area, so the finished field stays intact. We will tell you up front if a spot genuinely can't be reached without an interior cut.

Do you coordinate with our plumber and schedule?

Yes. We sequence the dig so the access is open when your plumber is ready to rough in, and we return to backfill after the inspection passes. Working inside a GC's timeline is most of the job.

Is it safe to tunnel near the foundation?

It is when the people digging understand foundations. We dig with the grade beams and bearing points in mind, shore the bore to OSHA practice, and flag anything that needs an engineer's input before we proceed.

Do you backfill so we can patch the slab?

Yes. We backfill and compact in lifts so the subgrade is ready for a slab patch and finishes. You won't get a soft spot under the new floor later.

What slows a remodel dig down?

Two things, mostly. Utilities nobody drew, since prior work often added lines that aren't on the original plans, which is why Texas 811 gets called before every dig. And a fixture location that moves after we have set the bore. Lock the fixture plan before we start and the access date holds.

From real jobs