Slab Leak Repair Cost: Detection and Fixes (2026)
💰 Cost Breakdown
| Item | Low | Average | High |
|---|---|---|---|
| Electronic Leak Detection Professional leak detection using acoustic listening devices, electromagnetic pipe locators, and thermal imaging to pinpoint the leak's location without destructive exploration. Essential before any repair — you need to know exactly where to dig or whether to reroute instead. | $150 | $300 | $500 |
| Spot Repair (Jackhammer Access) Breaking through the concrete slab at the leak location, repairing or replacing the damaged pipe section (typically 2–5 feet), and patching the concrete. Best when the leak is a single isolated failure and the rest of the under-slab piping is in good condition. Most common for newer homes with copper supply lines. | $800 | $1,500 | $2,500 |
| Pipe Reroute (Overhead Through Attic/Walls) Abandoning the leaking under-slab supply line and running a new line overhead through the attic, walls, or ceiling. Avoids slab penetration entirely. Best when the under-slab piping is old or likely to fail again soon (galvanized, polybutylene, or corroded copper). Leaves abandoned pipe in place under slab. | $1,500 | $2,500 | $4,000 |
| Tunnel Under Foundation (No Interior Damage) Digging a tunnel beneath the foundation from the exterior to access the pipe without breaking interior flooring. Used when the leak is near the foundation edge and interior flooring (tile, hardwood) would be extremely expensive to repair. More common in commercial work but available for residential. | $2,000 | $3,500 | $6,000 |
| Full Repipe (Abandon All Under-Slab Lines) Running entirely new supply lines through attic/walls to every fixture, abandoning all under-slab piping. The nuclear option — but often the right call for homes with multiple slab leak histories, polybutylene or galvanized under-slab piping, or when the cost of repeated spot repairs exceeds a one-time repipe. | $4,000 | $7,000 | $12,000 |
| Concrete and Flooring Restoration Patching the concrete slab and restoring flooring after a spot repair. Concrete patch alone is minimal, but matching tile, hardwood, or polished concrete adds significant cost. Not applicable for reroute repairs that avoid slab penetration. | $200 | $800 | $2,000 |
Electronic Leak Detection
Professional leak detection using acoustic listening devices, electromagnetic pipe locators, and thermal imaging to pinpoint the leak's location without destructive exploration. Essential before any repair — you need to know exactly where to dig or whether to reroute instead.
Spot Repair (Jackhammer Access)
Breaking through the concrete slab at the leak location, repairing or replacing the damaged pipe section (typically 2–5 feet), and patching the concrete. Best when the leak is a single isolated failure and the rest of the under-slab piping is in good condition. Most common for newer homes with copper supply lines.
Pipe Reroute (Overhead Through Attic/Walls)
Abandoning the leaking under-slab supply line and running a new line overhead through the attic, walls, or ceiling. Avoids slab penetration entirely. Best when the under-slab piping is old or likely to fail again soon (galvanized, polybutylene, or corroded copper). Leaves abandoned pipe in place under slab.
Tunnel Under Foundation (No Interior Damage)
Digging a tunnel beneath the foundation from the exterior to access the pipe without breaking interior flooring. Used when the leak is near the foundation edge and interior flooring (tile, hardwood) would be extremely expensive to repair. More common in commercial work but available for residential.
Full Repipe (Abandon All Under-Slab Lines)
Running entirely new supply lines through attic/walls to every fixture, abandoning all under-slab piping. The nuclear option — but often the right call for homes with multiple slab leak histories, polybutylene or galvanized under-slab piping, or when the cost of repeated spot repairs exceeds a one-time repipe.
Concrete and Flooring Restoration
Patching the concrete slab and restoring flooring after a spot repair. Concrete patch alone is minimal, but matching tile, hardwood, or polished concrete adds significant cost. Not applicable for reroute repairs that avoid slab penetration.
📊 Factors That Impact Cost
Repair Method Chosen
High ImpactA spot repair is cheapest upfront ($800–$2,500) but only fixes one location. If your under-slab piping is aging copper, galvanized, or polybutylene, it may leak again elsewhere within a year or two. A reroute ($1,500–$4,000) or full repipe ($4,000–$12,000) costs more now but eliminates future under-slab failures entirely.
Supply Line vs. Drain Line
High ImpactSupply-side slab leaks (pressurized hot or cold lines) are easier to detect and can often be rerouted overhead. Drain-side slab leaks (sewer lines under the foundation) cannot be rerouted — they rely on gravity and must maintain slope. Drain repairs almost always require jackhammering or tunneling, making them $2,000–$5,000+ more expensive.
Flooring Type Above the Leak
Medium ImpactIf a spot repair requires breaking the slab under carpet or vinyl, flooring restoration is cheap ($100–$300). Under tile ($500–$1,500 to match) or hardwood ($800–$2,000+), restoration may cost more than the plumbing repair itself. Expensive flooring often tips the decision toward rerouting instead of spot repair.
Pipe Material and Age
Medium ImpactCopper supply lines develop pinhole leaks from soil chemistry or water chemistry — one leak often predicts more. Polybutylene (gray or blue flexible pipe, 1978–1995) fails systemically and justifies a full repipe at the first slab leak. Cast iron drain lines corrode from inside out and typically need section replacement.