Decking - ledger board position and fixing problem

Discussion in 'Getting Started FAQ' started by highlander7, Aug 9, 2018 at 7:12 PM.

  1. highlander7

    highlander7 New Member

    We're just completing a new build extension and planning to build a deck out from it, ie 2.5m out by 5.0m across approx. Deck boards 5.0m to run perpendicular to building so joists 2.5m going out from building.

    There is a patio doors pvc sill below which there is a gap then the concrete sill - the sills are 3m wide. They protrude from the wall about 4 - 5cm (roughcast). Distance from top of pvc sill to underside of concrete sill is 10cm. Air bricks 20cm down from that.

    I want to end up with top of decking sitting a little below the pvc sill but above the concrete sill.

    Planning permission specifies 150mm x 50mm joists. The problem is that if I fix the ledger to the wall immediately below the concrete sill packed out by 10mm the top of the deck boards will come part way up the concrete sill.

    I have two possible solutions but wondered what you think please and if there is another way ?

    1 Ledger 150x50 just under the concrete sill, attach 150x50 joists with hangers then screw 50x50 to the top of all the joists to raise their level before attaching deck boards. The 50x50 would stop just before reaching the concrete sill.

    2 Use 200x50 joists and ledger but cut away middle 3.0m of ledger down to 150mm. Use 200x50 joists but cut away last 4cm length by 50mm depth to allow for concrete sill. Using 200x50 seems excessive though.

    I'll have a row of intermediate posts so was thinking that the joists on the other side would just be as normal, ie 150x50 set 50mm higher than those in option 1 or would start 50mm up from the bottom of the 200x50 in option 2.

    Any ideas please ?
    Thanks
     
  2. Jord86

    Jord86 Well-Known Member


    Post a couple photos of your situation so we can get a better idea please.
     
  3. highlander7

    highlander7 New Member

    Thanks - here you go

    from right - right side.JPG right side - close up.JPG straight on - right side.JPG
     
  4. Jord86

    Jord86 Well-Known Member

    Far simpler solution, disc cut and small chisel breaker the protruding part of the concrete cill off flush, then bolt your ledger wherever you want it.
     
  5. highlander7

    highlander7 New Member

    Thnx. Yes, had thought about that initially but wasn't keen as it's just been built and I'd then have to bolt very near the top of the wall and/or the concrete sill. I'm still thinking option 1 and adding to the top of the 150x50 but just not sure if that's OK.
    Cheers
     
  6. Jord86

    Jord86 Well-Known Member

    It will be fine.
     
  7. highlander7

    highlander7 New Member

    Thanks Jord :)
     
  8. ginger tuffs

    ginger tuffs Member

    could you pack framing out to cill level then run deck boards under patio cill
     
  9. highlander7

    highlander7 New Member

    Thanks. I had also wondered about that but it would mean that, instead of just packing it out the usual 10mm, I'd need to pack it out 40mm - 50mm and wasn't sure if I could do that and how I'd do it. D'you think it could be done ? Cheers
     
  10. ginger tuffs

    ginger tuffs Member

    just screw packing wood to wall to be level with concrete cill then run joists for decking to it
     
  11. highlander7

    highlander7 New Member

    Sorry if I'm not picking you up correctly - say ledger needs to be out 57mm from wall, do you mean to cut sections of 150x47 say 150mm wide to use as packing pieces for each through bolt then bolt through ledger and packing piece and 10mm square washers into wall ? Max fixing thickness for 180mm Rawlplug M12 through bolts is 85mm but I'd need to fix at least 104mm with this setup; longest throughbolt screwfix have is 180mm so not sure if I can get longer. Thanks
     
  12. ginger tuffs

    ginger tuffs Member

    bolt packing to wall then screw decking joists to packers
     
  13. highlander7

    highlander7 New Member

    Sorry but do you mean have a series of packing sections say 150mm wide of 150x47 spaced out 10mm and bolted to the wall then joist hangers directly on to these sections, ie no ledger at all with joists extending above hangers ? Tried to illustrate in attached. Thanks. screwfix001.jpg
     
  14. ginger tuffs

    ginger tuffs Member

    just bring packing out to cill level then screw joists to packers as you have draw ie its like having a double joist
     
    Last edited: Aug 10, 2018 at 6:22 PM
  15. highlander7

    highlander7 New Member

    OK thanks. Will have a think as the joist is running perpendicular to the wall.
     

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