Pipe expansion noise (ticking as pipes heat and cool)

Symptoms

• Ticking or popping sound heard shortly after hot water starts or stops
• Sound seems to travel along the pipe run
• No leaking or other symptoms present
• Noise is more noticeable in walls or under floors near hot water lines

Likely causes

• CommonMetal pipe expanding as hot water passes through itCopper and other metal pipes lengthen slightly with heat, and if not free to move, they catch and release against framing, producing a tick.
• CommonPipe fitted too tightly through a stud or joist holeWithout room to slide slightly during expansion, the pipe binds against the wood, creating friction noise.
• PossibleMissing or worn pipe isolation material (foam sleeve) at contact pointsA small cushion between the pipe and framing can prevent this friction noise entirely.

What to do

1. Note where along the pipe run the ticking seems loudest, using accessible areas like a basement or crawlspace if possible.
2. Look for spots where the pipe passes tightly through a framing member with no wiggle room.
3. Where accessible, enlarge the hole slightly or add a sleeve, or wrap the pipe with foam pipe insulation at that contact point to cushion movement.
4. For pipes secured too rigidly with metal straps, replace tight metal straps with cushioned, plastic-lined clamps that allow slight movement.
5. If the noise is coming from inside a finished wall you can't access, this is more of a nuisance issue than a safety concern and can often be left alone.
6. If it bothers you enough to address a wall-enclosed section, a plumber can assess whether opening the wall to add isolation is worthwhile.
7. This noise doesn't typically indicate any actual damage or failure risk to the plumbing.

Tools and parts

• Pipe insulation
• Cushioned pipe clamps

When to call a pro

A plumber isn't usually necessary for this cosmetic noise issue, though one can help if you want to address a section hidden in a finished wall.

Safety