Underfloor heating worries

Discussion in 'Plumbers' Talk' started by sj007, Aug 1, 2020.

  1. sj007

    sj007 New Member

    Hi guys,

    I'm having some trouble with my builder and the plumber who fitted my underfloor heating. In a nutshell, the plumber has laid Hetta aluminium pipes over c. 40 square metres comprising of two zones. The builder has then laid around 6cm of semi dry aggregate-based fibre screed. He's then added self level compound on top. The only thing left to lay is karndean vinyl floor.

    The problems I have identified to date are as follows :-

    1. The water pipes were not hot when the screed was laid so I am worried that when they heat and expand, it will crack the screed. (I'm not sure whether this was the plumber or builders responsibility)

    2. No insulation was applied around the edging of the screed so I guess there's a risk of cracking either within the screed or the wall plaster (again not sure if this was builder or plumbers responsibility)

    3. The self level compound that's been applied was 10 bags of Palace compound mixed with 4 bottles of Febflor latex and 6 part water. (I'm not so worried about this given it's only about 2-3mm in depth).

    particularly on the first point, it would be great to know what others recommend I do now? It's been about 3 weeks since the screed was laid so I believe it's too early for my to switch the heating on. I've got to make a call on whether I either :-

    a) Crack on with laying the vinyl floor and fitting the kitchen and hope for the best


    b) dig it all back out and do it again. This will cost c. £500 for the screed and another £1500 for the underfloor heating (presuming the pipes can't be saved).

    Would welcome all opinions.



    Attached Files:

  2. rogerk101

    rogerk101 Screwfix Select

    Firstly, the water pipes should NOT have been hot or even warm when the screed was laid. In fact you're not supposed to turn your heating on for at least the first month after the screed is laid. However the pipes should have been pressurised to 6 bars and left at 6 bars for a month. If this was not done, then your plumber/builder cocked up.

    If you're thinking about ripping it all out and starting again, wouldn't it be worth waiting to see if that's necessary? It may be that you're overreacting to something that is only a potential problem, but may end up not being a problem at all.

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