I've been trying to track down some very annoying 'ticking' sounds that happen within seconds of the central heating coming on. I know that it likely to do with copper central heating pipes under the floorboards being incorrectly held in place (e.g. too tight against a joist).

I have, I think, narrowed it down to where a single pipe passes under an internal wall. Taking floorboards up either side of the wall has allowed me to hear the ticking each side as if coming from the other side of the wall.

I noticed that the hot water pipe (15mm) is held firmly by mortar between the bricks of the internal wall. Is that standard practice or is it bad? Could it really be causing the ticking sound? (If so, how come copper hot water pipes can be laid under concrete and not tick?)

I have all the floorboards up at the moment so I really need a quick sanity check from someone knowledgeable!

1 Answer 1


That could definitely be causing a ticking sound if the pipe is moving it will clink against the mortar and possibly loud enough to hear.

There is nothing wrong with having mortar around it other than a PITA if you need to replace it. What you need to do is make sure that the pipe is secure as possible (tie-downs, clamps, whatever) on each side. You could also try wrapping the pipe in cloth to reduce sound or if you have a gap to hit it with spray foam.

  • Thanks. The pipe is really tight in the mortar - no wiggle room at all. I'm assuming the (quite loud) ticking sound is because the pipe has no play but wants to expand. Where it is expanding to exactly I don't know. Should I try to knock some of the mortar out to free up the pipe?
    – Ben
    Dec 4, 2014 at 15:06
  • The mortar is just clamping the pipe and keeping it into place. Same principle if you put hangers or hooks to do the same. Taking the mortar out is not going to hurt anything. just clamp it down if it has movement later. Pipes make noise.
    – DMoore
    Dec 4, 2014 at 15:15
  • Thanks, I think I'll to loosen it a bit. Surely pipes shouldn't make that much noise though - I can hear this ticking from downstairs and it has been known to wake my kids up. I lived in a modern (built 2010) house before and never had any problems like this. Current house is from 1970. Maybe the modern house had plastic pipes?
    – Ben
    Dec 4, 2014 at 15:27
  • 1
    Modern houses have copper and pex in the US. If the copper is moving it clinks if it is expanding it makes kind of a knocking sound - if close to something. If it clinks we throw sleeves around it or secure it better. If it knocks we throw sleeves around it (or rags) or sometimes just give it more space. But when you give it space like you are doing you might be trading the knocking in and get the clinking.
    – DMoore
    Dec 4, 2014 at 15:56

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