Forum

Replies

• PRO

  John Culpin October 6, 2017 at 7:45pm

  Hi Sam

  Looking my span tables you could get away with a 7x2 C24 graded timber, but if it were me then I would just use some more 8x2's which could be C16 graded if that is all you can get hold of/ cheaper than C24.

  regards

  John
• PRO

  Andrew Betteridge October 6, 2017 at 7:53pm

  Personally I would install more 8"×2" joists in between the existing, then install one or two runs of solid bridging, being solid timber packers to stop the joists twisting and making them a lot firmer.
  
  Andy
• 

  Sam October 6, 2017 at 8:45pm

  Thanks guys.

  So this is what I was thinking - current 8x2's are in brown, additional timbers in orange. I was hoping to save on weight, labour and of course material cost by just using 6x2's.

  Are you both saying 6x2's wouldn't be up to the job in this case?

  (Just wanted to make sure I had explained it properly)

  

  
  • PRO

    John Culpin > Sam October 6, 2017 at 10:00pm

    Hi Sam
    If you use joist hangers to connect the new timbers to the old then you will be able to use 6x2 as you are splitting the span into 2.
    If it was one of my jobs then I would still go with 8x2s as the money saved using 6x2s would be balance by the additional cost for joist hangers and the additional labour.
    John
• 

  Paul Keeley October 6, 2017 at 10:05pm

  I'd use 8x2" C16. Any span greater than 2.5M should have strutting to prevent the joist from twisting, this can be herringbone (metal nowadays usually) or timber. So for that deck you would only need one row of strutting along the centre line.

  With regard to the 6x2, the recommended size is 195x45 C16 @ 450 centres.

  The span Is still 3.6M unless you are planning on putting more pillars in the centre, which would half the span as it is supported.

  Hope that helps.

  Paul
• 

  Sam October 7, 2017 at 8:44am

  Thank you all - really appreciate the input! 
• PRO

  Neal Barker @ Etesia uk October 7, 2017 at 1:52pm

  6x2 should be fine as long as you noggin them throughout, the 8x2 sound like they have taken the load fine over the years the only issue was someone decided to skimp on them and set at 900 centre's which is creating less of a solid platform and more of a pool spring board in the middle of each joists,
  6x2 will take that extra bounce out fine and if posted down the line to would be so strong you could park a tank on it.
  
  Other thought is depending on fixings they used is use a reciprocating saw and site blade to chop and relocate original joists keeping external frame and then infill gap with new joist's
  It's a few hours more work however you will know everything will be set right and firm and your then not relying on someone else's work to hold yours because once that top is on any moving etc will be under your name not the previous persons
  • 

    Sam > Neal Barker @ Etesia uk October 8, 2017 at 10:45am

    Thank you so much! Really appreciate your comments! I'm going to remove all the deck boards (rather than just my trial 3) and then order timber after I've seen what the entire frame is like. I'm under the impression it has 8x2 noggins anyway so all I'd need to do is add separate 6x2 joists and like you said, I'm sure they will take up that slack just fine!