Can someone explain timber grades

Discussion in 'Carpenters' Talk' started by Retired, Apr 24, 2005.

  1. Retired

    Retired Guest

    I have seen the terms C16 and C24 used. What do these mean, and are there other numbers I should know of.
    Thanks
     
  2. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    No, I can't. I can tell you that these are strength grades, and range up to 32 or something, that being hardwood so I would guess 16 would be somewhere on softwood, and something to do with drying in kilns etc

    Not much help but there you are.


    Handyandy - really
     
  3. dirtydeeds

    dirtydeeds New Member

    not much more help than andy but it is to do with stress grading. each individual length of timber is put through a bending machine and stamped with its stress grading.

    CLS (canadian lumber stock) is the only timber that I know that is always graded. i have seen other timber that is graded.

    my local travis perkins sells proper CLS and most of the lengths are graded C16, a few lengths are C18

    the reason for saying proper CLS is that some timber looks like CLS but isnt. proper CLS has black markings in english and french, havent read them, but it does have the stress grade.
     
  4. dewaltdisney

    dewaltdisney New Member

    Slight correction DD it stands for Canadian Lumber Standard and is as you say a rating of strength for constructional timbers.

    In all there are 16 strength classes set by the European standard BS EN 519, ranging from C14, the lowest softwood strength class through to D70 the strongest hardwood strength class.

    So if you are using timber for building then this grading is important but if it is being used for furniture then it is less important and the moisture content is of more relevance.

    Hope this helps,

    DWD
     
  5. goldenboy

    goldenboy Super Member

    timber grading is a load of old nonsense i used to work in a timber yard and they used to grade softwood c16 and c24 all they used to do was look at it and then stamp it
     
  6. Retired

    Retired Guest

    If what Goldenboy says is anywhere near universal practice. Then it may not be worth paying for C24 over C16.
    But is it worth paying for C16 over wood with no grading at all?
     
  7. orangetlh

    orangetlh New Member

    I used to work for a timber merchants too. The C16 that was bought in was the worst quality timber ive ever seen. Also its only classed as C16 in the state that its been tested, so if you want it cut or regulised then it looses its rating. As was said before we had to stamp the C24 ourselfes and most of it was sub standard.
     
  8. yochippie

    yochippie New Member

    Retired.

    Then it may not be worth paying for C24 over C16.
    But is it worth paying for C16 over wood with no
    grading at all?

    depends what you want it for. Only if it is seriously structural (big trusses in cut roofs, joists - trimmed/trimming especially etc) is it a worry. Stud for partition doesn't warrant anything but the cheapest (generally)
     

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