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    • CommentAuthordelprado
    • CommentTimeMar 14th 2017
     
    It is stupid that Travers and every mainsteam merchant often stores c24 kiln dried outside, only to soak up more moisture, often it is cupped too.

    What can I get really decent timber from?

    Thanks
    • CommentAuthorcjard
    • CommentTimeMar 14th 2017
     
    Are you expecting a bit of rain to prevent it from reaching equilibrium after you install it in a building?
    • CommentAuthordelprado
    • CommentTimeMar 14th 2017
     
    I previously installed things perfectly only to then hear it creak over a series of weeks and no longer be mm perfect.

    But more importantly when strengthening joists, even though I am using epoxy resin to fill gaps i dont want cupping. I want it to be dead
    • CommentAuthorowlman
    • CommentTimeMar 14th 2017
     
    If you want to minimise cupping you'll have to go for slower grown stock, possibly another species, or quarter sawn or all three. Cupping is usually a result of through and through sawn stock, not fully dry when converted, and when that coincides with most commercial constructional timber it's inevitable.

    Just a thought, what do you understand by cupping, and what section and eventual use, are you talking of.
    • CommentAuthordelprado
    • CommentTimeMar 14th 2017
     
    It is in the context of sistering two floor joists together. I want a flush fit.

    I don't understand why you cant get C30 in this country either. C24 untreated is also hard to get.

    Does anyone know what is typically in the treatment that is applied to structural timber? I'd probably like to avoid it for first floor joists
    •  
      CommentAuthorfostertom
    • CommentTimeMar 14th 2017
     
    V gd Qs - looking forward to answers
    •  
      CommentAuthordjh
    • CommentTimeMar 14th 2017
     
    Posted By: delpradoWhat can I get really decent timber from?

    In my case I got excellent service, timber and prices from a local timber merchant recommended by my carpenters - Woollards of Mildenhall.

    I didn't have any problem getting untreated C24 from them, in fact they supplied it instead of C16 sometimes. And very few pieces twisted or bent. I think the restricted number of grades is down to economies of scale, and perhaps familiarity on the engineers' part. Nowadays if you need something better than C24, you probably reach for an engineered product.

    You don't need treated timber for first floor joists. We only used treated for sole plates and battens for cladding. You'd need to ask your supplier what treatment chemical they used. I believe BASF supply most of it.

    Timber moves; that's just a fact of life.
    • CommentAuthorowlman
    • CommentTimeMar 14th 2017
     
    Most of the C16, C24 graded stock is machine graded and stamped. Not each individual piece but by species and batch, (I guess) groupings. It is possible to get hand graded stuff but you'll obviously pay more. Most of it is untreated, where did you get the idea its mostly treated.
    Raw softwoods from the USA are often grouped into 1,2,3,4,5,6 and referred to as fourths or fifths etc , just to confuse: 4 5 6 are usually graded. 1,2,3,sometimes occasionally 4 are sold as unsorted. Most timber merchants will only have grade 3 unsorted. Grades 1 and 2 unsorted are a bit like the proverbial rocking horse s...t. The door and window manufacturers snaffle most of the grade 2 and Mr Velux and their ilk etc get all the grade 1.
    If you have a local timber merchant ask for some best grade unsorted and get it re-sawn or even PSEd and get them to hand grade it if you need certification.

    Alternatively, go for engineered.
    • CommentAuthordelprado
    • CommentTimeMar 14th 2017
     
    Thanks all so far

    Every single merchant around here only does c24 treated
    •  
      CommentAuthordjh
    • CommentTimeMar 14th 2017
     
    Where are you?
    • CommentAuthorEd Davies
    • CommentTimeMar 15th 2017
     
    I'm not really sure about this but I think there's a difference between treated and treated. There's the pressure treated stuff that you'd use for sole plates and the like then there's the run-of-the-mill graded timber which has a quick layer of yellowish treatment on the outside and which is pretty much standard just to preserve it until it's installed. At least that's what I gather from talking to the local merchants but I might have got the wrong end of the plank.
    • CommentAuthorowlman
    • CommentTimeMar 15th 2017
     
    I you don't need the "C" ( whatever) stamp on the timber you may find CLS ( Canadian Lumber Standard) more to your liking. It's widely available in untreated is "nicer" to handle and, although it may not be available in the sizes you need. I've a feeling that all CLS is the minimum C16 but can't prove it.
    • CommentAuthordelprado
    • CommentTimeMar 15th 2017
     
    DJH - Bournemouth

    Ed - that makes sense.
    •  
      CommentAuthordjh
    • CommentTimeMar 15th 2017
     
    Posted By: delpradoBournemouth

    I'm just wondering whether there is a greater prevalance of treated timber in your area because you have termites? Even if you don't need protection, maybe the merchants need to protect stock in their yards?
    • CommentAuthordelprado
    • CommentTimeMar 15th 2017
     
    Interesting djh I didn't even know that, the problem is asking basic questions seems to blow their minds.
    •  
      CommentAuthorfostertom
    • CommentTimeMar 15th 2017 edited
     
    Remember that (Canadian) CLS (and American ALS) is massively reduced from nominal size by apx half an inch off both dimensions - nominal 4x2 is flimsy 89x38. I'm amazed that Structural Engineers seem to take no account of that.

    I like sawn regularised - where 6mm is taken off the principal dimension by re-sawing or planeing it to make it flat/straight, but the other dimension is left unreduced as originally sawn. It may be a little bent in that direction but doesn't matter - unless hoping mythologically to be able to slot 400mm or whatever insulation boards tight between! So nom 4x2 is 95x47-50.
    • CommentAuthorcjard
    • CommentTimeMar 16th 2017
     
    Ever wonder whether the difficulties you encounter are a result of unreasonable demands for precision in an industry that doesn't really require it?
    • CommentAuthordelprado
    • CommentTimeMar 16th 2017
     
    cjard - I know what you are saying, but I bet its not like this in countries with higher quality housing.

    And just because builders merchants don't stock wood fibre boards and clay plasterboards does not mean that gypsum products are better, or that anything extra is superfluous (for example). It seems to me that this country just tries to do everything as cheaply as possible in construction materials, presumably because land is disproportionately expensive.

    And clearly in many situations you really do need precision. PVA, for example, has no strength if there are significant gaps in the wood and two pieces don't have enough contact area.
    • CommentAuthorDarylP
    • CommentTimeMar 16th 2017
     
    indeed... that is why we have to buy 310ml cartridges PU 'bubble glue' by the case!:shamed:
    • CommentAuthordelprado
    • CommentTimeMar 16th 2017
     
    Have you considered using epoxy resin? Thats what I am going to use for double up old joists, I think
    • CommentAuthorDarylP
    • CommentTimeMar 16th 2017
     
    funnily enough, We have just started to look at it. My cousin installs ER floors, and has introduced me to the variety of different formuale and uses...!:wink:
    •  
      CommentAuthordjh
    • CommentTimeMar 16th 2017
     
    Posted By: DarylPindeed... that is why we have to buy 310ml cartridges PU 'bubble glue' by the case!

    Posted By: delpradoHave you considered using epoxy resin? Thats what I am going to use for double up old joists, I think

    If you get PU on your fingers it makes them go black for a while. If you get epoxy on your fingers, nothing happens and then one day you may wake up with an epoxy allergy. So epoxy needs more careful handling than is typical when sloshing most woodworking glues around. But it is good stuff.
    • CommentAuthordelprado
    • CommentTimeMar 16th 2017
     
    Thanks very much for the heads up DJH
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