Depth of footings for decking in London

Discussion in 'Builders' Talk' started by Bivs, Mar 5, 2020.

  1. Bivs

    Bivs New Member

    Hi All,

    First time on the Screwfix Community forum, although I have read lots of posts via google searches. My Question, I am looking to build some decking in my garden, being a confident carpenter I have no problems building the actual decking structure, however, I am struggling to find a definitive answer to how deep I should dig my footings. I am intending on using concrete poured into cardboard tube footings with a 200mm diameter spaced 2.3 meters apart. The main area of the decking will be approx 7 meters x 5 meters with a couple of walkways coming off it. I live in zone two London, so the soil is a clay type which I have heard requires deeper footings. There will be no real weight on the decking except for a seating area and maybe the occasionally BBQ with guests. Any thoughts welcome, thank you.
     
  2. rogerk101

    rogerk101 Screwfix Select

    It's not really depth you want ... more surface area. If you increased your tubes to 300mm then you could probably get away with 500mm depth.
     
  3. stevie22

    stevie22 Screwfix Select

    You really need to look at the ground you're digging: if soft go deeper. I'd probably settle for 2 feet in old money if the ground was ok.
    The other thing I'd do is dig my holes about 300 across, pop 150 of concrete in then use your 200 sleeves. The advantage of doing it this way is that you get the same bearing surface but use less concrete, and you can tweak the alignment of the sleeves once the concrete is in to get a dead true line.
     
  4. ginger tuffs

    ginger tuffs Screwfix Select

    just dig to hard ground and insert concrete blocks and build of blocks the more block you put in is better and dont forget damp under deck post
     
    WillyEckerslike likes this.
  5. WillyEckerslike

    WillyEckerslike Screwfix Select

    It used to be the case that if the decking was more than 300mm above ground, planning permission was required. Not sure if that's still the case.
     
  6. Bivs

    Bivs New Member

    Thank you everyone for your advice, very much appreciated.
     
  7. rogerk101

    rogerk101 Screwfix Select

    I think 300mm above the surrounding ground is the height above which you good olde Health and safety REQUIRES you to put up a balustrade to prevent deck users from plunging to theirs deaths.
     

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