Quick Answer:
If you hear a new rattling after repiping, the pipe run is likely contacting framing, cabinets, or loose hangers and vibrates when water moves. Run a few basic checks to find where the vibration starts and whether it’s just noise or a potential movement issue. If access is limited or the run is near wiring or finished ceilings, have a plumber locate and secure the run safely.
Why This Happens
New piping sits differently than old lines. Thermal expansion, pressure surges, or a change in how the pipe is clipped to joists can make it touch wood, metal, or drywall. That contact turns normal flow vibration into an audible rattle. Small differences in support points after repiping are the most common cause.
If the noise is tied to an appliance or a specific area, check those locations first — for example, see Rattling when washing machine fills or Rattling near water heater for appliance-specific patterns and fixes.
Step-by-Step What to Do
1. Confirm when the vibration happens
- Run the fixture slowly then fully to see when vibration starts. For example, open a faucet slowly and note whether the rattle begins at low flow, medium, or full flow.
- Try different fixtures on the same feed (toilet, sink, shower) to narrow down which run is involved.
2. Localize the run by listening
- Listen from adjacent rooms and move along walls while someone else runs the fixture. This helps pinpoint the general area of the pipe run.
- Check floors above and below if possible to determine vertical routing.
3. Feel for movement
- Press lightly on nearby walls, cabinets, or baseboards while the water runs to feel for vibration or movement transferring to the finish.
- If you can access an exposed section of pipe in a crawlspace or basement, put a hand on the pipe to feel where the vibration is strongest.
4. Inspect visible supports and clearances
- Look for loose hangers, missing clips, or pipe rubbing where it passes framing or cabinets. Tighten accessible clips and replace worn hangers if the pipe is exposed and you are comfortable doing so.
- Do not force or pry in finished ceilings or walls; if the pipe is behind finished surfaces, skip to the next step.
5. When access is limited
- If the run is behind a wall, above a finished ceiling, or near electrical wiring, stop and call a plumber to locate and secure the run safely. A professional can use a stud camera or pipe locator and install proper supports without damaging finishes.
What Not to Do
- Don’t open walls or wedge random shims blindly — that can damage finishes and hide the real cause.
- Don’t jam pieces of wood, brick, or metal into cavities hoping to stop noise; this can shift piping and create new stress points.
- If the rattle is near wiring or finished ceilings, let a plumber locate the pipe first rather than cutting or chasing it yourself.
When to Call a Professional
- Call a plumber if you can’t safely access the run, if the rattle coincides with visible pipe movement, or if the noise started after a pressure change and you suspect a loose support.
- Also call if the rattle comes with other signs — leaks, banging (water hammer), or changes in pressure — so a pro can diagnose and secure the piping properly.
- A plumber can locate hidden runs, add the correct clips or braces, and ensure fixes comply with code without harming finishes or nearby wiring.
Safety Notes
- Do not cut into ceilings or walls near electrical fixtures or wiring. If you must open a finish, hire a professional who can locate electrical and plumbing safely.
- Turn off water to a fixture before attempting any repairs on exposed piping. If you are unsure how, get a plumber to avoid water damage.
- Avoid makeshift fixes that put pressure on pipes or fittings. Proper clips, isolation pads, and rated hangers are the safe solution.
Common Homeowner Questions
- Is rattling dangerous? Not usually by itself, but it can indicate loose supports that may cause wear or leaks over time.
- Can I stop it with foam or insulation? Small dampening pads can help where the pipe rubs on framing, but only on exposed runs and with proper clip spacing.
- Will a plumber need to open walls? Often not — a plumber can locate runs and secure pipes from accessible points, but hidden sections may require minimal access depending on the situation.
For more related articles, see the Rattling Pipes Inside Walls hub.