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Cracks in wall - what is your opinion on this?

  • 18-05-2021 10:44pm
    #1
    Registered Users Posts: 95 ✭✭ Robert Allen


    Hi all,

    Im wondering if you could advise re: the following. Ive a good few horizontal hairline cracks in my external walls. Running along the Blockwork where the radon barrier is.

    Any ideas of why this happens or if i have a problem on my hands?

    Thanks a mill,

    Rob.


Comments

  • Registered Users Posts: 3,105 ✭✭✭ 10-10-20


    Some randomer who isn't a structural engineer on the internet said...: ;)

    It's hard to see from the photo due to the lack of perspective, but is that a poured horizontal slab, with the rake-marks on it? Can the slab expand on the opposite side or is it up against another wall?

    To me it appears to be where the slab has expanded into the render due to a lack of an expansion filler. AJ himself covers it off here in the first section/image: https://www.pavingexpert.com/concjnt1
    Whether it's a problem or not depends. But does the DPM have sufficient clearance from the top of the slab? Again, I'l refer to AJ:
    https://www.pavingexpert.com/dpc01


  • Registered Users Posts: 95 ✭✭ Robert Allen


    10-10-20 wrote: »
    Some randomer who isn't a structural engineer on the internet said...: ;)

    It's hard to see from the photo due to the lack of perspective, but is that a poured horizontal slab, with the rake-marks on it? Can the slab expand on the opposite side or is it up against another wall?

    To me it appears to be where the slab has expanded into the render due to a lack of an expansion filler. AJ himself covers it off here in the first section/image: https://www.pavingexpert.com/concjnt1
    Whether it's a problem or not depends. But does the DPM have sufficient clearance from the top of the slab? Again, I'l refer to AJ:
    https://www.pavingexpert.com/dpc01


    Hi thanks a mill for replying to that. What you see is a trad strip foundation and cavity wall - the block behind the plaster is cracking where its resting on radon barrier. Under the radon barrier there is solid block footing. The DPC is on top of the block and behind the block- in the cavity is bead insulation. Hoping its just settlement of some type. I just haven't seen much of that before and its not entirely obvious why its happening.


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