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Cavity wall partly below external ground level

Discussion in 'Building' started by magicnumber7, 20 Sep 2020.

  1. magicnumber7

    magicnumber7

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    The engineer's drawings for our single-story rear extension specify 3 courses of engineered brick (below external ground level) on the outer skin of the cavity wall. It looks like the contractor is planning on bringing the concrete higher and then starting straight away with about 1 course of block work below ground level, thus no engineered brick below ground level. The comments on the video imply raise this questions: there is some debate about whether this is 'standard', 'quick and easy' or 'corner cutting'. Should I be concerned?

    ()
     
    Last edited: 20 Sep 2020
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  3. tony1851

    tony1851

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    What does this mean? - a view of the drawing would help.

    (Engineering bricks are normally only used under certain conditions, eg high loads (not applicable in an extension); chemically agressive soils; or to act as a dpc and protect non- frost-resistant bricks near ground level).
     
  4. magicnumber7

    magicnumber7

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    Have updated the post above - hopefully clearer.
     
  5. ^woody^

    ^woody^

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    o_O Dafuq?

    They are and have been routinely used in any wall under any load below DPC.
     
  6. ^woody^

    ^woody^

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    Concrete can come up to ground level with no performance issues.

    The only problem may be with altering external ground levels and laying paving, and with getting the floor slab and insulation in internally.
     
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  8. JohnD

    JohnD

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    Engineering bricks are more expensive so perhaps the builder is planning to out the extra ££ in his pocket.

    Raise this before he builds the wall, or he will use the old "too late now, you should have told me sooner" routine to try to make it your fault.
     
  9. ^woody^

    ^woody^

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    Where do you do your shopping?

    Class B's are 41p each around here, and facings start at 59p each and London bricks are 85p each, all plus VAT.
     
  10. magicnumber7

    magicnumber7

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    How so?

    In our setting, the neighbours side along our extension flank wall is about 300mm higher than our ground level. So it looks as though builder will put block along that section (and then DPC above the neighbours ground level). Make sense? Guess I am wondering how much of an issue, if at all, it is to use blocks there instead of engineered bricks for either 1) stability or 2) damp. Cheers.
     
  11. ^woody^

    ^woody^

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    It depends on the frost rating of whatever blocks will be used.

    DPC and DPM deal with damp
     
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