Table with wood properties

Discussion in 'Materials' started by gonzo, Sep 20, 2015.

  1. Grey Ghost
    Joined: Aug 2012
    Posts: 194
    Likes: 9, Points: 0, Legacy Rep: 94
    Location: california

    Grey Ghost Senior Member

    Building inspectors won't fail a framing inspection because studs have knots, small splits, parts missing on corners, bark in places, etc. They're "suitable" I guess according to building code even when individual pieces have lots of flaws that will be covered over. When you want something where lumber will be visible and extraordinary, either you have to pay for higher grade lumber or you have to pick thru.
     
  2. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 474, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I don't buy lumber I can't sort through, even large lots. In fact, I will not buy a large lot, unless I can select it. This assumes I'm not building a deck or a stud wall for a house. With this stuff, it's much simpler just to get what you need at the local big box, use what you need, return and swap out what you can't use, etc. The only time I don't do this is with quality plywood. My supplier knows I'm anal about it and doesn't send anything that I wouldn't approve. He knows I'll return it, so he sends the good stuff. He's actually called and said he has enough in stock for the order, but a few of the sheets aren't up to snuff "should I send them anyway?". Maybe it's different in the lots I get. If you buy a pallet of 1/2" BS-1088, they're pretty good about keeping you happy.
     
  3. TANSL
    Joined: Sep 2011
    Posts: 6,116
    Likes: 269, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    OK, ask forum members who buy wood if they would do the same as you. Why, in your opinion, the strategy of buying wood is different from other products in bulk?
    I did not say, nor have I thought, that's a lie. It could be, for example, a dominant position of the seller to compel the buyer to accept harsh conditions. How can I say that someone is lying if I have no proof ?. All that is hard to believe is not necessarily a lie.
    It was not my intention at all to offend anyone and do not think anyone can feel offended by a colloquial innocuous expression that no misconduct.
     
  4. whitepointer23

    whitepointer23 Previous Member

    Sorry, i misinterpreted your post.
     
  5. TANSL
    Joined: Sep 2011
    Posts: 6,116
    Likes: 269, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Whitepointer23, I think you're an honest person. I also try to be.
    Cheers
     
  6. gonzo
    Joined: Aug 2002
    Posts: 14,343
    Likes: 619, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    The difference is that wood is not an isomorphic material and is not produces under industrial quality controls.
     
  7. TANSL
    Joined: Sep 2011
    Posts: 6,116
    Likes: 269, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Lets pedants : Isomorphic definition
    adjective
    1. Biology. different in ancestry, but having the same form or appearance.
    2. Chemistry, Crystallography, isomorphous.
    3. Mathematics. pertaining to two sets related by an isomorphism.
    -------------------------------------------------------------------------------
    It would be more appropriate to say that wood is a inhomogeneous material ?. Probably yes.
    Gonzo, I do not know very well the meaning you give to that little word but you'd be amazed to know how many products that can be purchased and despite not having a homogeneous properties, the seller does not increase the price for that "imperfection".
     
  8. Grey Ghost
    Joined: Aug 2012
    Posts: 194
    Likes: 9, Points: 0, Legacy Rep: 94
    Location: california

    Grey Ghost Senior Member

    Do you mean "perfection" or "imperfection"?

    What you get at most lumberyards is pricing set by building grade acceptance of "imperfection". Homebuilding has low standards IMO for common lumber because most home-buyers never see the lumber inside the walls. What buyers see is the trim which is priced higher for knot and spilt free.

    Most of the time the yard isn't going to care when a few people pick thru a bunk to pick the better boards (at no extra cost) as long as most customers don't spend the time to do it. Depends on the lumberyard near you. The lumberyard wants to sell every board in the bunk and not have to write any of the boards off. When you take advantage of the cheap or free flatbed delivery you don't get to pick.
     
  9. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 474, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Lumber is priced on effective usable area unit per dollar. #2 grade will have so much area per unit, #1 will have considerably more for the same unit, etc.

    Plywood is priced by the cubic foot and is for all essential purposes, a homogeneous product, as are most "sheet goods". Of course, different panel build qualities can affect the unit pricing on plywood, but this is simply quality grading (a BS-6566 sheet being less costly than a BS-1088 sheet, etc.)

    As to selection, some lots simply aren't practical to sort through. If you order a few pallets of 1/2" plywood, you better have a very friendly vendor, as unbanding, sorting through and rebanding a pallet, isn't typically an expense most will permit. I'm lucky, I'm only 15 miles from one of the country's largest suppliers and they know me and my needs (I'm not the only nut job they know). This isn't practical on most large lots or with most vendors.
     
  10. Petros
    Joined: Oct 2007
    Posts: 2,936
    Likes: 139, Points: 63, Legacy Rep: 1593
    Location: Arlington, WA-USA

    Petros Senior Member

    rough framing of lumber is one step up from fire wood, or wood for palets or crates that will be scrapped after the mercandise it is protecting is shipped.

    But than rough framing lumber has VERY large safety factors as compared to clear straight grain lumber, and most of it never gets seen. In fact the vast majority of lumber in a house or light commercial building is not even under heavy loading. Top and bottom plates, rim boards, blocking, all interior walls, etc only have to hold up interior wall finish or are used only in compression in confined installations.

    Nearly all the better quality wood is separated by the mill and sell it higher prices for finish work or specialty use (such as furniture or boat building). Even some of the larger commercial yards will hand pick out the better pieces of sawn framing lumber that the mill misses, and put them in a separate pile at higher cost (and why those yards do not let you pick your own). If you order all #1 or Select strutural floor joists they will charge you a lot more for sorting it for you. That is why you are more likely to find the odd good clear lumber in a big box store stack, they just inventory the pallets of lumber in the mix as they arrive from the mill, all at the same price.

    If it was not for the large amount of low grade lumber that these stores buy, I would not be able to occasionally find a good pace at a low price in the big box stores.

    Lumber is like anything else: you do not use use the same grade of concrete on a residential side walk as you would on the foundation of a 100 story building. Nor would you use the same type of steel on a toaster housing as you would on the engine mounts on a jet fighter. You get what you pay for. But if you dig a little, and are patient, you can get some decent lumber from the stacks. Otherwise you pay the extra price for someone else to select out the clear lumber.
     
  11. LP
    Joined: Jul 2005
    Posts: 1,411
    Likes: 57, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Different table of wood properties.

    This table is a little more comprehensive of wood species is the US primarily, but may be useful abroad as it lists some imported woods as well. These properties may be a little more inline with hand picked wood used in our boat projects.

    http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch04.pdf

    I like that it gives both metric and empirical (?) units. It also lists strength properties for green wood and 12% moisture content. There is also content regarding the various wood properties that is later in the tables. A good "snow day" read. :D
     

  12. gonzo
    Joined: Aug 2002
    Posts: 14,343
    Likes: 619, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    That is very comprehensive. It tests straight grained, knot free wood. They call it commercially available, so I assume it is second growth or farmed. Since they give the density values, it should be easy to compare to actual samples.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.