utterly confused with CLS timber sizes

Discussion in 'Carpenters' Talk' started by tehvlb, May 17, 2017.

  1. I certainly am. Imperial is a far better system.
    One things the americans have definately got right by sticking to feet and inches.
     
  2. sospan

    sospan Screwfix Select

    I grew up with pounds and shillings and imperial measurements, certainly wouldn't want to go back
     
  3. tehvlb

    tehvlb Member

    deck, table, play house for the wee man.
     
  4. chippie244

    chippie244 Super Member

    Generally if you get a timber size in metric it is the finished size wheras if it is in imperial it is the sawn size so if PAR it will be around 6mm or 1/4" less.
    CLS is simply a grading for wood and comes in many sizes.
    I think lengths in imperial or metric but all other measurements are in metric and I work in millimetres.
     
  5. sospan

    sospan Screwfix Select

    Some measurements will always stay because of the language - miles, inch, 8x4, even MPG is still a quoted figure although we haven't sold fuel by the gallon for a long time
     
    chippie244 likes this.
  6. vivaro man

    vivaro man Active Member

    I'm with Sospan on this one. I'm 65 and it took me a year to get my head around metric and now I love it, it's much more logical to think in units of ten. Younger chippies look cross eyed when I occasionally slip back into yards, feet and inches. Mind you then they say things are da bomb and it's sick. You what?
     
  7. Dr Bodgit

    Dr Bodgit Super Member

    Litres per 100 kilometres anyone? I have no idea what that equates to in mpg.
     
  8. tehvlb

    tehvlb Member

    SO is the thinner 4x2 CLS just as strong as the thicker 4x2 CLS.

    If i am looking at a span table for deck build for instance doesnt it make sense that thinner wood is weaker so therfor the span would be less?
     
  9. Dr Bodgit

    Dr Bodgit Super Member

    Thinner wood is certainly weaker than thicker wood. Is there a "4x2" equivalent CLS/metric size? If so I would think it would be 100x50 which regularised would be 97x45 or something similar, perhaps the timber I got which is 95mmx45mm.
     
    tehvlb likes this.
  10. tehvlb

    tehvlb Member

    thats exactly what i assumed the dimensions would be.

    It would be good to know what size (metric or imperial) span tables are based on.
     
  11. dwlondon

    dwlondon Active Member

    The finer details are measured in tads and smidgeons or gnats eyelashes.
     
  12. Dr Bodgit

    Dr Bodgit Super Member

    Its gnats kneecaps.
     
  13. tehvlb

    tehvlb Member

    http://www.allowaytimber.com/c16_span_table.php

    timber span tables are based on these sizes

    so 45mm x 95mm would be 2x4

    so it would seem that to comply with regs one would need to find a merchant that supplied that size of 2x4 instead of their "custom" size
     
  14. DIYDave.

    DIYDave. Screwfix Select

    Apart from the sizing issues, can't believe how cheap the CLS is, and apart from studwork, it has loads of uses

    Recently bought a load from Trade Point (borrowed a card) ! Had a deal on +20 lengths 2.4s, was around £2.40 a length, just seems crazy cheap. Was building some racking in garage and planters for garden and handy having a few spares whilst at that price :)
     
  15. Pollowick

    Pollowick Screwfix Select

    Not significantly - the rough sawn has all the exposed cut fibres which offer very little strength, so by taking 1 to 2mm off each side you are not reducing the strength by very much. Strengths of timber are probably based on it having been planed smooth. And then every piece will be different and strength based on something near the minimum found in that timber type.

    Then remember with C14, C16, C18, C22, C24, C27, C30 (and more) the grading can be visual.
     
  16. tehvlb

    tehvlb Member

    Dr Bodgit likes this.
  17. sospan

    sospan Screwfix Select

    Higher up the thread, I mentioned I made a sideboard top out of the same stuff. However, I opened a sealed pack and got some really dry and straight lengths. I normally pay around £2 for a 2.4m length, prices my local timber merchants can't get near.

    I normally keep a stack of the smaller cls around as it so useful for formwork, creating moulding or even temporary work shelter using tarpaulin
     
  18. tehvlb

    tehvlb Member

    what was the length of it mate?
     
  19. DIYDave.

    DIYDave. Screwfix Select


    As mentioned, 2.4s ;)
     
  20. Pollowick

    Pollowick Screwfix Select


    Have a read of the Wickes page ... at one point it says C16 Regularised 45 x 95 x 3000mm then later on it r
    efers to Nominal size 47 x 100mm and also that sizes are approximate! I thought that the idea of regularised timebr was that is was always the same size, with a little tolerance but not 5mm.
     

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