Leak Repair Cost 2026: From a $10 Fix to a $5,000 Slab Leak
Leak repair costs span a wider range than almost any other plumbing work. The difference between a $15 DIY fix and a $3,000 professional repair is usually just which component failed. Here's the full spectrum.
2026 leak repair costs by type
| Repair | DIY Cost | Pro Cost | Notes |
|---|---|---|---|
| Supply line (under sink/toilet) | $10–20 | $75–175 | Easy DIY — braided hose swap |
| P-trap replacement | $10–25 | $100–200 | Easy DIY — no tools needed |
| Toilet flapper | $5–15 | $75–150 | 5-minute DIY repair |
| Faucet cartridge repair | $15–50 | $150–300 | Moderate DIY — brand-specific parts |
| Shut-off valve replacement | $15–40 | $150–300 | Requires main shutoff; moderate DIY |
| Pipe repair (accessible, minor) | $10–50 | $200–500 | Clamp or coupling repair |
| Pipe leak inside wall | Not recommended | $500–1,500 | Includes opening and patching wall |
| Slab leak repair | Not DIY | $500–4,000+ | Detection + spot repair or reroute |
What to check before calling a plumber
Many leaks that look like they require a plumber are actually straightforward DIY fixes. Before calling:
- Is it under a sink? Read the under-sink leak guide — supply lines and P-traps are the most common source and both are easy DIY.
- Is it a dripping faucet? A worn cartridge or O-ring. Many faucet brands sell cartridge replacement kits for $15–50.
- Is it a running toilet? Almost always the flapper ($5–15) or fill valve ($15–30). Both are 15-minute DIY jobs.
- Is it a pipe leak? If it's accessible (not in a wall or under a slab), a pipe repair clamp buys you time. Clamp guide here.
If it's inside a wall, under a slab, or at a gas line, call a plumber. The risk and complexity aren't worth the savings.
Back to all cost guides.