Filling concrete channel with heating pipes within - what to do?

Discussion in 'Plumbers' Talk' started by RMHaz, May 21, 2022.


Filling concrete channel/chase with heating pipes within

  1. Yes - the plumber's suggestion is correct

    0 vote(s)
  2. No - you need an alternative option (please suggest)

    1 vote(s)
Multiple votes are allowed.
  1. RMHaz

    RMHaz New Member

    Hi everyone,

    I had a leak in my CH pipes running through my kitchen.

    Pipes have been replaced - not only the damaged section, but we ran new pipes up to the radiator as it turns out when this radiator was installed last year, the flooring guys filled the channel with concrete.

    My concern was this meant no room for pipes to move or expand, so to avoid potential future issues due to this, we layed new pipes around and to the rad.

    Now, to avoid repeat errors concerning filling the channel, I need to know what to use to fill the this around the pipes, then put a layer of concrete on top (the floor is concrete) then reapply the karndean/antico flooring. 16531410982357527306447455119197.jpg 16531411246642662592053611145445.jpg 16531411400357226537224609266588.jpg

    So my question is what to use to fill the channel around the pipes before the concrete goes on top? The plumber suggested embedding the pipes in sharp sand, then a layer of shingle on top, then the concrete layer on top of that.

    Looking online it seems there are conflicting theories - I just want to know if the above is a valid option, or others that be be equally valid and correct.
  2. chesterw

    chesterw Well-Known Member

    The chase should have been made wider to accommodate a 50x100 electrical steel trunking with lid, this would allow for pipe movement.

    Or, bring pipes up in the corner and run on surface, with expansion allowance at the corner.

    Your plumbers idea is the worst solution as it would prevent any movement.

    Also the RHS rad connection is too tight coming up through the floor.
    Cliff Rees likes this.
  3. RMHaz

    RMHaz New Member

    I should mention that my integrated fridge unit is normally in the corner but had to be removed to access that are as this is where the leak was traced to. So the fridge will be reinstalled back there.

    Not looking to run pipes on surface - they need to stay in the floor.

    I have no plumbing experience, so saying the rad connection is too tight out the floor is unclear what you mean by this.

    The building is about 30 years old so all CH pipes live in the concrete floor and don't have trunks with lids.

    Your suggestion is one I have seen met with mixed feelings and responses elsewhere online.
  4. Cliff Rees

    Cliff Rees Active Member

    Had exactly the same problem about 10 years back. Used a loose Vermiculite fill around pipes and screeded over top. Vermicullite has supported screed ok with no signs of cracking or movement.
    jimbobby likes this.
  5. Notnowvicar

    Notnowvicar Screwfix Select

    Cliff Rees likes this.
  6. exbg

    exbg Screwfix Select

    EVERY new build (using copper) that I have seen has the Cu covered directly by the screed. I have never seen it ducted. Furthermore, the layer of sand will allow for slight expansion, and is probably a better idea than that which is normally employed.

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