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DPM On Hardcore

Discussion in 'Building' started by Skavenger, 15 Aug 2017.

  1. Skavenger

    Skavenger

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    Hi;

    I am laying some hardcore in advance of concreting a garden workshop floor. Do I need to put anything on top of the hardcore before laying a DPM? It looks as though it may get punctured / torn on the hardcore edges?

    Thanks
     
  2. 23vc

    23vc

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    Sand blinding, lots of info on this forum or Google
     
  3. KenGMac

    KenGMac

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    Skavenger, good evening.

    Suggest you consider a layer of sand between DPM and hardcore.

    But? the sand can wash out if the edges are not closed of with a brick perimeter wall or similar. mixing cement will reduce leaching of the sand.

    The most commonly used material is a so called "Lean mix Concrete" a "Weak Concrete mix" generally 50.mm thick, generally less than 7.5 Kn. Can you adjust the heights to accommodate the Lean mix?

    Ken.
     
  4. Skavenger

    Skavenger

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    I could 125mm hardcore, 50mm weak concrete and 75mm concrete?

    What would be a weak mix 10:1 (Ballast / Cement)

    But sand would be easier, the hardcore comes to the top of my wall footings so the sand would be encased by four walls. So I just even out the hardcore with sand?

    Sharp sand or builders sand?
     
  5. Red_Shift

    Red_Shift

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    Sharp sand
     
  6. 23vc

    23vc

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    I used building
     
  7. ^woody^

    ^woody^

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    Soft building sand
     
  8. Skavenger

    Skavenger

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    Thanks everyone - looked and sand binding seems the simplest option.
     
  9. DIYnot Local

    DIYnot Local

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