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Top of foundation - depth below ground level

Discussion in 'Building' started by macadonald, 20 Oct 2012.

  1. macadonald

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    Hi guys,

    I can't find a post I viewed a while back that showed nicely with pictures how to mark the top of the foundation level, so that when it's being poured you know it's level.

    My trenches were finished today. What a horrible job, bagging hundreds of bags of clay. Anyway, I have bought a water level, for marking out with dowlings stuck into the side of the trenches. Main question here is what depth these should be below ground level. I have 150mm in my head, is this right? Pretty sure I don't want it poured right up to ground level.

    Many thanks
     
  2. freddymercurystwin

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    The level needs to be coursed to suit any existing floor or masonry levels you are matching up with.
     
  3. ^woody^

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    Concrete top can be at any depth below surface. But work it so that it works guage to bricks or blocks and from the lowest ground level
     
  4. macadonald

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    Thanks.

    The outside ground is a good 30cm below inside floor level and the house is rendered. The extension will have a few courses of engineered bricks to dpc, but the rest will be blocks and rendered, so there is not much to tie in with visually. The floor will be suspended timber.

    Thinking about what you've advised, I suppose it would be worth tying in the dpc levels as best as possible. So perhaps I should locate the dpc on the existing house and measure down bricks height plus the number of mortar beds required.

    Assuming this, can I assume that the mortar bed below the first course of engineered bricks is the same thickness as any other mortar beds?
     
  5. freddymercurystwin

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    What about the door openings or windows? You want to end up with a predicted threshold detail that ties in with your existing floor level depending on your cill/floor finishes etc not end up with needing dafter slither of blockwork to get you where you want to be. If you are building your joists into the inner skin or they're on hangers then this needs consideration too wouldn't you say? The bottom joint can be bigger to allow for rough/non level foundations but theoretically is the same as the rest.
     

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