Warning Signs of a Slab Leak
Warm or hot spots on the floor (usually the hot-water side leaks first), unexplained increases in your water bill, the sound of running water when nothing is on, mildew or musty smells in carpet, cracks in flooring or drywall, low water pressure, or the water meter dial spinning when all fixtures are off. If you notice any two of these together, get a professional leak detection.
Why Fresno Homes Are Vulnerable
Fresno sits on expansive clay soils that swell in winter rains and shrink in dry summers. This annual ground movement stresses copper supply lines encased in the concrete slab foundation. Homes built 1960s–1980s are especially vulnerable — that's when copper-under-slab was standard construction. Fig Garden, Tower District, Bullard, and parts of Northeast Fresno have the highest concentration of slab-leak calls.
Leak Detection
Professional slab leak detection uses acoustic listening devices, thermal imaging cameras, and pressure testing to locate the leak within a few inches. Detection alone typically costs $250–$500 and is a separate charge from the repair. DIY detection is generally not reliable — misidentifying the location can lead to unnecessary slab cutting.
Repair Option 1: Spot Repair
The plumber cuts open the concrete slab directly over the leak, replaces the damaged section, and patches the concrete. Cost: $1,500–$3,500. Best when: it's a single, isolated leak in a home with otherwise good piping. Downsides: your flooring in that spot is destroyed and must be replaced; if there's one leak, more may follow in the next few years.
Repair Option 2: Overhead Reroute
The plumber runs new PEX or copper piping through the attic and down the walls to bypass the slab entirely for the leaking line. Cost: $2,000–$4,500. Best when: only one line is affected and you want to avoid touching the slab. Downsides: doesn't fix other lines in the slab if they fail later.
Repair Option 3: Full Repipe
The whole house is replumbed with new PEX or copper running through walls and attic. Cost: $6,000–$12,000 for a typical 3-bed home. Best when: the home is 40+ years old, you've already had one slab leak, and you plan to stay in the home. Downsides: cost, and drywall patching (often not included — get this in writing).
Insurance Considerations
Standard homeowner's insurance typically covers the water damage from a slab leak but not the repair itself. Document everything with photos. File the claim before you dry the house out — insurance adjusters want to see the extent of damage. If your policy has a "loss assessment" or "service line" endorsement, you may get partial repair coverage. Call your agent first.
Frequently Asked Questions
Can a slab leak fix itself?
No. Slab leaks only get worse over time. Every day of leaking wastes water, damages your foundation, and grows the eventual repair scope. The moment you suspect one, shut off the water when leaving the house and get a professional detection.
How long does slab leak repair take?
Spot repair: 1–2 days including concrete cure time. Overhead reroute: 1 day. Full repipe: 2–5 days. Drywall patching after any of these is usually another 1–3 days.
Do all Fresno plumbers do slab leak repair?
Most licensed plumbers can do the repair, but leak detection is a specialty — not everyone owns acoustic and thermal detection equipment. Ask specifically about detection capability before booking. Companies like Allbritten, Stedman's Plumbing, and Rod's Plumbing all have this equipment in-house.