Minor Pipe Leak? How to Assess and Fix It

A visible pipe leak is stressful, but not all leaks require a plumber. Loose connections under a sink, weeping compression fittings, and dripping P-traps can often be fixed by hand. The key is identifying what type of pipe and connection you're dealing with.

What's Happening

Pipe joints can loosen over time from vibration, thermal expansion, or mineral buildup. Drain pipes under sinks use slip-nut connections that can be hand-tightened. Supply lines use compression fittings or braided connectors that may need a wrench. The severity ranges from a slow seep to an active drip — the faster the leak, the more urgently it needs attention.

What to Check

1. Locate the exact source. Dry off all visible pipes with a towel. Place a dry paper towel under the area you suspect. Run water and watch carefully — leaks can travel along a pipe before dripping, so the drip point isn't always the source.
2. Identify the pipe type. White PVC or black ABS drain pipes use slip-nut connections you can tighten by hand. Chrome or brass trap pipes are similar. Braided stainless supply lines connect with compression nuts. Copper pipes use soldered joints — don't attempt these yourself.
3. Tighten slip-nut connections (drain pipes). If the leak is at a PVC slip-nut joint under the sink, try hand-tightening the nut a quarter turn. If it's still dripping, remove the nut, check that the washer inside isn't cracked or missing, replace if needed, and reassemble.
4. Tighten supply line connections. For braided supply lines, use an adjustable wrench to snug the compression nut an eighth-turn. Don't over-tighten — you can crack the fitting. If the braided line itself is leaking, replace it entirely.
5. Apply a temporary fix if needed. For a slow seep you can't fix immediately, use plumber's epoxy putty or self-fusing silicone tape as a temporary seal. Then schedule a proper repair within a few days.