Block vs 90/170mm timber carcassing - strength? Feel?

Discussion in 'Builders' Talk' started by CrawfW, Aug 8, 2018.

  1. CrawfW

    CrawfW Member

    Evening,

    I'm planning a garden studio, and was thinking of timber-framing - until i got worried about how solid it would end up feeling.

    Would 170mm carcassing, at 600mm centres, create a much stronger final building than 90mm?

    I'm also worried about the sense of strength. For example, if walls made from single skin blocks are a "10" - on my invented tap-test scale - what are 90mm and 170mm timbers like?

    Guessing this might not make sense, or that i might get ripped a new one for having such a strange question, but here goes....

    :)

    Crawf
     
  2. Jord86

    Jord86 Well-Known Member

    Let me put your mind at rest. Most national housebuilders in this country build their timber frames from 89mm x 38mm C16 softwood, clad with 11mm OSB to give an overall internal skin of 100mm, that ground floor structure incorporates roughly a tonne or so in weight of joists and chipboard flooring plunked on top, which in turn supports the upper floor panels, which in turn supports several tonnes of roof structure and tiles. Obviously the footings and foundations are calculated meticulously to be able to bear the loads, but comparable to a garden studio, if 89mm timber will build a home for someone to live in, it's more than capable for what you want.
     
  3. stevie22

    stevie22 Active Member

    If you want to insulate the thing then 125 timbers will allow you to put 100mm of Celotex in the wall which will keep you toasty warm and will feel nice and solid. Just because housebuilders cut things to the bone doesn't mean you have to and the cost difference won't be huge
     
  4. CrawfW

    CrawfW Member

    So, Stevie22, would you stop at 120? I was thinking of 170, or even 195 (!) as it isn't much more expensive. Indeed, the timber is a small part of the build cost.

    Ultimately, the aim of the game is to build something that feels like it might have been cast from solid......
     
  5. chippie244

    chippie244 Well-Known Member

    Why not just build it out of brick.
     
  6. stevie22

    stevie22 Active Member

    Wash your mouth out Chippie
     
  7. Jord86

    Jord86 Well-Known Member


    Lets be realistic, this is a garden studio. You do what you want, it's your build, but if you look up any American timber frame construction videos on YouTube or whatever you'll find the vast majority of their external walls have been built with 89mm timber for the last 60 odd years or so, and now the UK has adapted the same. If built and tied together properly it will be as strong and warm as you want it.
     
  8. chippie244

    chippie244 Well-Known Member

    The OP is an idiot.
     
  9. Jord86

    Jord86 Well-Known Member

    Well, he said he's expecting to get ripped a new one in his first post.........now he has :)
     
  10. CrawfW

    CrawfW Member

    Thanks. Constructive.
     
  11. CrawfW

    CrawfW Member

    And so, that is the bottom line. Whilst people say they are happy with timber, 89mm or otherwise, the reality is that this is simply never as strong as a brick wall.

    Guess we end where we begin - i was originally going to use blocks, then thought surely timber must be fairly strong. Seems it really is only reasonably strong - in terms of walls. I appreciate its utility for joists, cathedral roofs etc.
     
  12. stuart44

    stuart44 Active Member

    It depends on what kind of strength you require. As a bricklayer I have a bias towards masonry construction, and there are certain advantages to it. However a timber construction can withstand ground movements better than a block building.
    The disadvantage with masonry is that it has a high compressive strength but not so much laterally.
     
  13. chippie244

    chippie244 Well-Known Member

    I refer to my previous post.
     

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