A pipe joint usually leaks because the seal between the two pieces has failed. That can happen from corrosion, worn washers or tape, loose threads, high water pressure, or pipes that move and strain the connection over time.
Common Causes by Joint Type
- Soldered copper joints: old solder can crack or corrode, especially where pipes heat and cool often.
- Threaded joints: common on galvanized steel and brass. Thread sealant can dry out, and rust can eat at the threads.
- Compression fittings: often under sinks and toilets. The small ring inside can loosen or wear.
- Push or crimp fittings: found on newer plastic lines. Damage or improper installation can cause leaks.
Other Factors
Pipes that are not well secured can shift when water turns on and off. That movement wears on joints. High water pressure adds stress on every connection. Water hammer, the banging when valves close fast, also strains fittings. In older homes, mixing different metals at a joint can lead to corrosion.
Signs of a Joint Leak
Look for drips at connections, green or white crust on fittings, rust stains, or damp spots under pipes. A slow joint leak may only leave a mineral trail at first. Over time, the drip often gets faster and the damage spreads.
Handling a Dripping Joint
Place a bucket under the drip and close the nearest valve if the leak is steady. Do not overtighten fittings with a wrench, since this can crack old pipes or strip threads. Tape or clamps can slow a drip for a short time, but they rarely seal a joint well.
Joints near water heaters and in hard-to-reach spaces deserve extra attention because leaks there can go unnoticed.
When a joint keeps dripping, redoing the connection properly is the lasting fix. For older pipes with many joints showing wear, you can talk with a plumber about the whole system at (833) 603-1840.