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Floor Screed V Sand and cement

  • 14-10-2021 2:42pm
    Registered Users Posts: 122 ✭✭ tcooley

    Hi there,

    I will be putting down the floor in a new build in a few weeks.

    150mm Xtratherm, underfloor heating etc.

    I keep hearing that builders are now going back to sand and cement instead of the screed for flooring.

    I had heard before that screed was best for underfloor but now I am unsure what to do.

    Would anyone have any ideas or recommendations?




  • Registered Users Posts: 97 ✭✭ Staleturnips

    There are pros and cons to both. I use S&C screed where specific floor level have to be met and associated tolerances are fine; I've use liquid where the maximum available thickness of the screed has excluded S&C as an option.

    Theoretically Liquid screed should provided a better media for the transfer of heat from UFH pipework to the floor build up vs. S&C screed; as the former fully encapsulates the pipework and has less air entrapment/entrainment which also hinders heat transfer.

    That said liquid screeds can not be finished to the same degree of surface flatness as S&C screeds. Obvously the quality of the finish is dependent on the individual floor layer but irrespective of that inherent properties of liquid screeds mean they cannot reach the same degree of flatness as S&C screeds.

    Lastly laitance is deposited on the cured surface of liquid screed and depending on what subsequent floor finishes that laitance layer may have to be removed; this removed by sanding.

  • Registered Users Posts: 122 ✭✭ tcooley

    @Staleturnips Thanks so much for that response, lot to read through there but great to get an expert view on it. Am a while away yet from flooring so I have a bit of time yet! Thanks again.