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Builder using sand to bring floor level up ?

Discussion in 'Building' started by LozM, 28 Jul 2021.

  1. LozM

    LozM

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    Hi,

    Builder has poured two separate concrete floors either side of a wall, the wall has now come down as going to be open plan area, and turns out floors are at different levels.

    The next step was going to be insulation board and then pipework on top for under floor heating and a liquid screed poured on top and then the long wait before porcelain tiles to finish.

    So today there was discussion on how to get floors to same level before putting the insulation board on top, the solution they came up with was to use sand they had on site to bring the lower floor up, don't think there is much difference in levels - about 20mm.

    Is this an acceptable/regular solution ? The kitchen with island is going on top of what is the lower floor raised with sand, guess will be quite compacted but concerned about movement or compression of floor over time. Area is about 4m by 4.5m.

    Any thoughts greatly appreciated,

    Lawrence
     
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  3. Mottie

    Mottie

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    Screed?
     
  4. Mr Chibs

    Mr Chibs

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    If you are having ufh, this can be embedded into the screed which sits on top of insulation.

    with this in mind, why not just have 20mm extra screed where it’s needed or 20mm more insulation?

    Not sure I’d want to use sand to bring up the level.

    Or you could use SLC (self levelling compound) on the low section.

    Others will share their thoughts.
     
  5. LozM

    LozM

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    Apologies do you mean they should have used screed rather than sand or questioning the screed going on top of the insulation board/pipes ? Very new to all of this,

    Lawrence
     
  6. LozM

    LozM

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    Guess that would mean the under floor heating in that section would be lower than in other section, they are going to be different zones so maybe not too much of an issue. Think the difference is quite small so extra insulation would raise it up higher. They have put the insulation boards down today so they would have to lift them up and remove sand which they are not going to be happy about so guess trying to gauge if it is an issue and worth making a stand on,

    Thanks, Lawrence
     
  7. Notch7

    Notch7

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    Use 2 different thicknesses of insulation.

    sand :ROFLMAO::ROFLMAO: - tell the builder to leave his horse at home tomorrow.

    I presume you mean concrete oversite is different level?
    And he is putting down insulation, underfloor heating pipes and screed on top (known as a floating screed as it’s not bonded to concrete)
     
  8. Notch7

    Notch7

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    Don’t accept sand - if the quibble say you had better get it approved by your building inspector.

    they can just buy some 20mm insulation and put it down first…..you might have an argument about who pays for it - you might do half each despite the fact it’s builders fault.

    gee every builder has a laser these days - setting a datum around is billy basic stuff
     
  9. LozM

    LozM

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    Yep the concrete across the two areas is at different levels as poured at different times before wall in between came down, I’m guessing from horse comment this is not a regular/acceptable solution - not going to go down well as I questioned it twice today and they assured me would be no movement, guess the easiest thing here is thicker insulation,

    Many thanks,

    Lawrence
     
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  11. Notch7

    Notch7

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    It’s not unheard of to use sand as a levelling medium, but extra insulation is foolproof….I wouldn’t let him get away with it.

    and It would probably need to be sharp sand, not builders sand.
     
  12. ^woody^

    ^woody^

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    Most modern concrete floor slabs are laid on a layer of just sand 20-50mm thick (building sand too), so there is no problem if they use a layer of sand on the concrete to bring up a level. After all where is the sand going to escape to once its compacted? :rolleyes:
     
  13. LozM

    LozM

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    That was builders theory but wander just how compacted it is given just got light insulation board on it then full weight of kitchen going on albeit above a screed snd tiles, just seemed if could be a problem now is time,


    Many thanks,

    Lawrence
     
  14. ^woody^

    ^woody^

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    They would compact it with a board or something.

    If you are worried, just ask them to sprinkle a bit of cement with it. It wont need to be a lot or a proper mix, but it will then bind the sand.

    But the way loads are spread around a floor, there is very little point loading anyway. Think about the snow shoes worn to walk on snow.
     
  15. noseall

    noseall

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    Sand is ok and is recommended by manu's.
     
  16. tony1851

    tony1851

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    Would sharp sand be better than ordinary building sand?
     
  17. ^woody^

    ^woody^

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    Any except egg timer sand. :cautious:
     
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