Weak mix in cavity up to dpc

Discussion in 'Builders' Talk' started by Turtletom100, Jul 6, 2016.

  1. Turtletom100

    Turtletom100 Member

    Hi all I'm helping a mate do a side extension and on the plans it says we need to weak mix in the cavity up to dpc level (is this 150mm or 225mm?)

    Also am I right in saying the weak mix should be about 8:1 quite wet?

    The bricks/block work to dpc should be wall tied aswell shouldn't they with no insulation just weak mix?

    Sorry for the dumb questions just want to be certain of a few things before helping from dpc up it is pretty straight forward.
     
  2. Phil the Paver

    Phil the Paver Screwfix Select

    ???????, up to DPC in the cavity.

    Any muck in the cavity should not be higher than 150mm below DPC.

    Ties are normal set directly on top of the DPC the stop insulation bats dropping below DPC.
     
  3. Turtletom100

    Turtletom100 Member


    The plans say that there should be weak mix put in cavity to dpc. So I assume that means up to 150mm below DPC?

    What do you mean stop insulation bats?
     
  4. Phil the Paver

    Phil the Paver Screwfix Select

    Like this, to stop the insulation bats falling into the cavity below DPC.


    baywindowsdpc.jpg
     
  5. Turtletom100

    Turtletom100 Member


    Cheers mate that helps alot build up fill cavity to 150mm beneath dpc level then start with the wall ties and insulation.
     
  6. Turtletom100

    Turtletom100 Member

    I wont need to use wall ties up to dpc level will I?
     
  7. Phil the Paver

    Phil the Paver Screwfix Select


    Depends on how many courses of bricks/ blocks you have to DPC, 6 or less then no.
     
  8. Turtletom100

    Turtletom100 Member

    I believe it is 5 courses so should be fine, will I need to use a cavity tray? Or will I be okie if i just put a slope towards the external brickwork?

    And last but not least going back a few years since I done bricking lol, is it every 5 or 6 courses a tie should be used and it's every 3/4 bricks isn't it?

    Thanks for your help aswell top bloke
     
  9. Phil the Paver

    Phil the Paver Screwfix Select

    Every 6 courses high, and 600mm apart is what I do.
     
    Turtletom100 likes this.

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