Slab-on-grade addition in Florida.

You have a code violation and a high probability of future leaks.

Code Violations (FBC 2023 / IPC 2021):

1. No Protection/Sleeving: FBC P2603.3 / IPC 305.6 requires pipes passing through concrete floors to be protected from shear stress and corrosion by a sleeve or wrap. Bare copper in concrete violates this.
2. No Expansion/Contraction Allowance: Monolithic pours lock the pipe rigidly. Slab shrinkage/movement shears the pipe or fittings at the stub-up.
3. Dissimilar Metal Corrosion Risk: Bare copper in direct contact with concrete (alkaline, chlorides) and potential rebar contact creates galvanic corrosion cells. FBC P2603.3.1 requires protection (tape, sleeve, or insulation) where pipes contact concrete.

What’s Coming:

• Pinhole Leaks: 2–10 years out at the slab penetration point or first fitting inside the wall due to corrosion/stress.
• Shear Failure: Slab settlement or thermal movement snaps the copper at the 90° ell inside the wall cavity.
• No Repair Access: Leaks under the slab require jackhammering the finished floor.

Immediate Remediation (Before Drywall):

1. Expose the Stub-Ups: Open the wall cavities at every penetration.
2. Install Repair Sleeves: Slide PVC or ABS sleeves (Sch 40) over the copper where it passes through the slab, extending 6" above finished floor. Seal the annular space at the slab with polyurethane sealant (not cement).
3. Add Expansion Loops/Offsets: Ensure the copper has a minimum 6" horizontal offset or soft bend inside the wall before the vertical riser to absorb slab movement.
4. Pressure Test: Re-test the system at 1.5x working pressure (min 100 psi) for 15 mins (FBC P2503.7) with the wall open.

If walls are closed: You own the liability. Document the violation with photos. Advise the owner in writing that this does not meet FBC/IPC and future leaks are excluded from standard warranties.

Disclaimer: I am an AI, not a licensed FL plumber/engineer. This work requires a licensed Florida plumbing contractor to correct and certify.

This is a serious code violation and a high-risk installation. In Florida, running 3/4" copper water lines directly through a monolithic slab-on-grade without a sleeve violates the Florida Building Code (FBC), Plumbing Chapter 605.3, which requires piping penetrating concrete slabs to be protected by a sleeve or conduit to allow for movement, prevent abrasion, and avoid damage from concrete shrinkage, settling, or shifting.

What’s coming?

• Leaks: Copper will rub against abrasive concrete aggregate over time, especially with thermal expansion/contraction and minor slab movement. Pinhole leaks are likely within 5–15 years.
• Corrosion: Concrete is alkaline and can accelerate copper corrosion, particularly if chlorides or moisture are present.
• Difficult repair: If a leak occurs, accessing the pipe requires jackhammering the slab — costly, disruptive, and risks damaging other utilities.
• No flexibility: Without a sleeve, the pipe cannot move independently of the slab, increasing stress at bends and connections.

What should have been done: The pipe should have been run through a PVC or ABS sleeve (minimum 2x pipe diameter) embedded in the slab, extending at least 1" above the slab surface, with the annular space sealed with flexible, non-hardening sealant (FBC 605.3.1). Stub-ups should be protected and accessible.

Action now:

• Pressure test the lines immediately and monitor for drops.
• Inspect accessible stub-ups for signs of moisture or corrosion.
• Document the installation.
• Consult a licensed Florida plumber or structural engineer — if leaks develop, repair may require slab cutting and rerouting.
• For future work: Always sleeve penetrations. This is not a DIY fix — it’s a latent defect requiring professional evaluation.

Note: If this is a permitted job, the installer may be liable for repairs under Florida’s construction defect statutes.