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Discussion Forum

What is 5/4 lumber?

blownonfuel | Posted in General Discussion on April 20, 2008 06:32am

Went to Lowes the other day and saw lumber labeled 5/4x6x8 or something to that effect. What dimension is the 5/4?

Thanks

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Replies

  1. GOLDENBOY | Apr 20, 2008 06:35pm | #1

    5/4 = 1 + 1/4

  2. rez | Apr 20, 2008 06:39pm | #2

    or close to 1 1/4 inch.

     

    be a 32nds

    Click here for access to the Woodshed Tavern

    Click here to visit the beginning of Breaktime

  3. DougU | Apr 20, 2008 06:40pm | #3

    5/4 to me usually means anything from about 1" to 1 1/8" thick.

    I've seen treated wood anywhere from 1" to 1 1/4" thick, depends on the dryness.

    so a 5/4" X 6" will be closer to 1" X 5 1/2" but the 8' should still be 8'.

    If I was buying 5/4" finished wood I'd expect it to be a consistent 1".

    Doug

     

     

    1. MikeSmith | Apr 21, 2008 01:34am | #13

      blow...... 5/4 refers to the rough size before the board was finishedit started out as 5/4... after it goes thru the planer it finishes at 1"common boards start at 4/4 and finish at 3/4"Mike Smith Rhode Island : Design / Build / Repair / Restore

  4. Schelling | Apr 20, 2008 06:41pm | #4

    5/4 lumber is lumber that was rough sawn to 1 1/4 inch. When it is finished planed as you would get at a retail lumberyard, it will measure about 1" though that can sometiimes vary upward.

    1. Jim_Allen | Apr 20, 2008 06:48pm | #5

      It must be a regional thing because 5/4 was always 5/4 in MI. The treated 5/4 stuff started at 5/4 when milled green but shrinks considerably. Finished 5/4 stock is milled after being kiln dried and retains it's full 5/4. Bob's next test date: 12/10/07

      1. User avater
        Matt | Apr 21, 2008 12:28am | #12

        I guess it is a regional thing.  Here 5/4 lumber has a finished thickness of 1".

        Reminds me of when I was a young buck working in a big box store.  Lady tells me "2x4s are only 1 1/2" thick?  That's false advertising".  Me trying to be polite: "Sorry mam.  It's an industry standard.  The boards were 2" thick before they were planed and sanded." 

        Really though I gotta wonder...  I'll betchya that the lumber industry now-a-day has it figured it out to where they can get a 2x4 out of a board rough sawn to 1 5/8".... 

        1. Schelling | Apr 21, 2008 02:04am | #15

          I am sure that you are correct with the large softwood lumber mills.

          We pick up our hardwood at the mill (and have them plane it to whatever thickness we want) and whatever the lumber measure 4/4,5/4,6/4,8/4 or more, that is what it measures. Sometimes a little more.

          And you need it.  If we try to get a little more thickness than usual, the roughness is not always planed off. If you can hide a slightly rough side, this will work. If not, use it somewhere else or plane it down.

    2. RW | Apr 20, 2008 07:46pm | #6

      I agree. And while it is going to vary a little from mill to mill, when talking hardwood, 5/4 is what the sawyer cuts in anticipation of yielding 1.25 after drying, but still rough. I've gotten rough 5/4 that netted 1.25 and rough 5/4 that netted a strong 1.5.

      I buy 5/4 all the time, straight lined and skipped at 1 3/16 and that removes on average 80% of the roughness.

      I could totally see though, in the framing lumber world, someone wants to sell 5/4 decking as a true 5/4 finished, thats specifiying to the mill what you want and putting a label on it. Our box stores, the finished is inch and an eighth, but . . .Real trucks dont have sparkplugs

      1. square668 | Apr 20, 2008 08:21pm | #7

        The actual dimension of a 1"x2" or 4/4"by8/4" is 3/4" by 1and1/2" so the nominal 5/4" is an actual 1".

        1. RW | Apr 20, 2008 08:39pm | #8

          You're talking about different things. Framing lumber isnt sold the same way as hardwood. One by, two by material - there the one by was an inch at one time, when it was cut. It finishes under. And its sold as surfaced all sides. So 2x is inch an a half. Sure. But you don't buy 2x white oak or cherry. You buy 8/4.

          Hardwood is sold in quarters. 4,5,6,8,12 . . . And its sold rough. If you go to a hardwood supplier and its surfaced, they spec'd it that way from the mill or distrubutor, whoever they got it from. And most do. If you're buying off the shelf, those guys don't want rough. They want to see the grain and what they're getting. A shop that buys a pallet that has 660bf or whatever on it, they're just buying volume. They have the ability to dimension it.

          Standard Thickness for Rough and Surfaced Hardwood Lumber

          1/4" System

          Rough Thickness

          Planed Thickness

          4/4

          1"

          13/16"

          5/4

          1-1/4"

          1-1/16"

          6/4

          1-1/2"

          1-5/16"

          8/4

          2"

          1-3/4"

          9/4

          2-1/4"

          2-1/16"

          10/4

          2-1/2"

          2-5/16"

          12/4

          3"

          2-3/4"Real trucks dont have sparkplugs

          1. square668 | Apr 20, 2008 08:53pm | #9

            OK

          2. User avater
            Jeff_Clarke | Apr 21, 2008 05:39am | #20

            Spot on!

             

            Jeff

  5. Piffin | Apr 20, 2008 09:30pm | #10

    Rough milled at about 1-1/4" thick, then planed and dry to about an inch. I see it ( depending on moisture, species and mill source) anywhere from 15/16" to almost 1-1/8"

     

     

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    1. blownonfuel | Apr 20, 2008 11:37pm | #11

      Thanks to all. I figured as much but thought I would ask.Thanks Again.

      1. JHOLE | Apr 21, 2008 02:01am | #14

        They gotcha covered on your original question, but I gotta ask - Blownonfuel?

        NHRA?, boats? are we talking nitromethane?Remodeling Contractor just on the other side of the Glass City

        1. User avater
          Sphere | Apr 21, 2008 02:27am | #16

          I thought huffing gas went out with "bennies"?Spheramid Enterprises Architectural Woodworks

          "Welcome to Poo-ville, can I have your socks?Seriously Folks, I need a home for 3 lovers of your life.

          1. JHOLE | Apr 21, 2008 02:30am | #17

            You're thinking nitrous oxide.

            Used to have that around the house/garage by the tankfuls.

            Gooooood stuff.Remodeling Contractor just on the other side of the Glass City

          2. User avater
            Sphere | Apr 21, 2008 03:17am | #18

            whippit good!Spheramid Enterprises Architectural Woodworks

            "Welcome to Poo-ville, can I have your socks?Seriously Folks, I need a home for 3 lovers of your life.

        2. blownonfuel | Apr 21, 2008 04:12pm | #22

          Hello JHOLE, Fuel Altereds forever!!!! NHRA. But I like anything that runs "the can".

          1. JHOLE | Apr 22, 2008 04:33am | #23

            "Fuel Altereds forever!!!! "

            I'll take that.

            NHRA here too.

            Lived it, love it. Not necessarily nhra, I'lll take IHRA, UDRA, PRDA,Nostalgia ( where it seems the real old fans appreciate the sport) you name it.

            Especially with what's going on lately.

            But, drag race for ever!Remodeling Contractor just on the other side of the Glass City

  6. User avater
    mmoogie | Apr 21, 2008 05:06am | #19

    My local hardwood yard mills their own pine and hardwoods in 5/4 that measures a true 1 1/8. And their 1x measures 13/16. Once you start using them for your 1x, you are spoiled. 13/16 is a lot nicer than 3/4.

    They told me that when 1x officialy dropped from 13/16 to 3/4 back in the day, they decided to stay at 13/16. I think it's worked well for them because everyone in the trades around here gets their trim lumber and hardwood from them.

    Steve

  7. User avater
    user-246028 | Apr 21, 2008 06:38am | #21

    5/4 is the pre-milled thickness, finished product  is actualy an inch thick. Same idea as a 2x4 actually measures 1 1/2 x 3 1/2

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