# When 10" isn't 10". A word about my lumber **URL:** \ **Category:** The BBQ Pit\ **Created:** [August 21, 2006, 3:37pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602 "2006-08-21T15:37:42Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![buttonjockey308](https://avatars.discourse-cdn.com/v4/letter/b/bcef8e/32.png) [@buttonjockey308](https://boards.straightdope.com/u/buttonjockey308)\ **Post date:** [August 21, 2006, 3:37pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/1 "2006-08-21T15:37:42Z")
So, it’s the weekend, plenty of projects around Rancho del Jockey, not the least of which is the reconstruction of the back deck. Which is a critical part of the house, as the roof extends over it. Nice for the summer, and rainy days and so forth. Anyhoo, I journey on down to the land of the orange aprons and vacant stares, to get some big boards, that I intended to cut into smaller boards, to create a nifty little staircase which I will use, on a daily basis, to exit my abode. The stringers for said staircase did, as advertised, possess a 10" tread area, (I know, I measured) so I felt justified purchasing the 16’ 2’’ x 10’’ boards for the stair treads without measuring them first. Oops. Turns out, those 2" x 10" boards are 2" x 9-1/4" That’s 3/4" of a bloody inch! That’s fuckin critical when you’re making STAIRS! When did the lumber industry decide that they would start nickel and diming us by shaving 3/4 of an inch off the boards? I mean, are you really saving THAT much money? And even if you are, so what, you’re ripping people off! Listen you fuckers, 2 by 10 means TWO by fucking TEN, not 1 and an eighth by 9 and a quarter but TWO by motherfucking TEN. And you, Home Despot, why not MARK the boards their TRUE size? Huh? Take too much ink to add in the fractions? Tell me, how is this fraud acceptable? What if, let’s say, I got to the register, and the board was (as this one was) $9.75 do you think I’d be able to say, “y’know, I’m only gonna pay the $9.00, it’s my standard practice to pay only round numbers” You think I’d leave with the board? Fuckers. and yes, I should have measured ---
**Author:** ![Sattua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sattua/32/11906_2.png) [@Sattua](https://boards.straightdope.com/u/Sattua)\ **Post date:** [August 21, 2006, 3:43pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/2 "2006-08-21T15:43:23Z")
I’ve got bad news for you. Two-by-fours aren’t actually two by four. ---
**Author:** ![Key\_Lime\_Guy](https://avatars.discourse-cdn.com/v4/letter/k/48db29/32.png) [@Key\_Lime\_Guy](https://boards.straightdope.com/u/Key_Lime_Guy)\ **Post date:** [August 21, 2006, 3:43pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/3 "2006-08-21T15:43:51Z")
No, I’m willing to wager your boards weren’t 2" x 9-1/4", they were 1-1/2" x 9-1/4". Two-by-fours are actually 1-1/2" x 3-1/2". Two-by-sixes are actually 1-1/2" x 5-1/2". These are lumber industry standards - been that way since WWII. Nothing to do with Home Depot. Most guys learn this when they are teenagers. Blame your dad. ---
**Author:** ![usar\_jag](https://avatars.discourse-cdn.com/v4/letter/u/f0a364/32.png) [@usar\_jag](https://boards.straightdope.com/u/usar_jag)\ **Post date:** [August 21, 2006, 3:48pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/4 "2006-08-21T15:48:38Z")
There’s a joke in your thread title somewhere. As stated by others, board sizes aren’t equal to their names. Here is a [conversion chart](http://www.mistupid.com/homeimpr/lumber.htm) that I googled. ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [August 21, 2006, 3:49pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/5 "2006-08-21T15:49:48Z")
Wait till you go looking for decking and the 5/4 isn’t. ---
**Author:** ![Freudian\_Slip\_1](https://avatars.discourse-cdn.com/v4/letter/f/f475e1/32.png) [@Freudian\_Slip\_1](https://boards.straightdope.com/u/Freudian_Slip_1)\ **Post date:** [August 21, 2006, 3:51pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/6 "2006-08-21T15:51:41Z")
Ah, the joys of woodworking. It sucks the first time you get bitten by this issue, but you don’t forget it. Try drawing out construction plans for something and forgetting to account for actual lumber measurements :smack: The measurement of lumber (“nominal size”) is before planing and shrinkage. Therefore, a 2x4 is actually 1 1/2" by 3 1/2". There’s a chart [here](http://en.wikipedia.org/wiki/Lumber). ---
**Author:** ![Contrapuntal](https://avatars.discourse-cdn.com/v4/letter/c/e274bd/32.png) [@Contrapuntal](https://boards.straightdope.com/u/Contrapuntal)\ **Post date:** [August 21, 2006, 3:54pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/7 "2006-08-21T15:54:26Z")
You haven’t really done a lot of lumber cutting, have you? ---
**Author:** ![Antinor01](https://avatars.discourse-cdn.com/v4/letter/a/ecae2f/32.png) [@Antinor01](https://boards.straightdope.com/u/Antinor01)\ **Post date:** [August 21, 2006, 3:56pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/8 "2006-08-21T15:56:31Z")
It’s quite simple actually, they’re men. Men always lie about the size of their lumber. ---
**Author:** ![DoctorJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/doctorj/32/2904_2.png) [@DoctorJ](https://boards.straightdope.com/u/DoctorJ)\ **Post date:** [August 21, 2006, 3:58pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/9 "2006-08-21T15:58:29Z")
_My_ lumber is a full 10", baby. ---
**Author:** ![Scarlett67](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scarlett67/32/7387_2.png) [@Scarlett67](https://boards.straightdope.com/u/Scarlett67)\ **Post date:** [August 21, 2006, 3:59pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/10 "2006-08-21T15:59:29Z")
> [@Freudian\_Slip](#): > > The measurement of lumber (“nominal size”) is before planing and shrinkage. Therefore, a 2x4 is actually 1 1/2" by 3 1/2". Cripes, I’m a GIRL and even I know that. ---
**Author:** ![Ludy](https://avatars.discourse-cdn.com/v4/letter/l/d6d6ee/32.png) [@Ludy](https://boards.straightdope.com/u/Ludy)\ **Post date:** [August 21, 2006, 4:06pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/11 "2006-08-21T16:06:10Z")
The change was explained to me by the lumber starting out at the advertised dimensions, and the loss comes when the wood is planed and finished. But I can’t remember who told me that so I could very well be wrong. ---
**Author:** ![Otto](https://avatars.discourse-cdn.com/v4/letter/o/bbe5ce/32.png) [@Otto](https://boards.straightdope.com/u/Otto)\ **Post date:** [August 21, 2006, 4:15pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/12 "2006-08-21T16:15:57Z")
> [@DoctorJ](#): > > _My_ lumber is a full 10", baby. Man, if I had a dollar for every time a guy told me that lie… ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [August 21, 2006, 4:22pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/13 "2006-08-21T16:22:57Z")
> [@buttonjockey308](#): > > When did the lumber industry decide that they would start nickel and diming us by shaving 3/4 of an inch off the boards?] Oh, maybe as much as 100 years ago. Boards as sawn from the log at the mill are the stated size: 2x4, 2x10, 4x4 etc. They are then planed down for smoothness which gives superiour handling characteristics. All structural load bearing characteristics are computed using the finished size. It’s sort of odd that someone who isn’t aware of this would take on the job of building a staircase which is one of the more sophisticated carpentry tasks. It could be worse. You could have started with a spiral staircase. ---
**Author:** ![Contrapuntal](https://avatars.discourse-cdn.com/v4/letter/c/e274bd/32.png) [@Contrapuntal](https://boards.straightdope.com/u/Contrapuntal)\ **Post date:** [August 21, 2006, 4:25pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/14 "2006-08-21T16:25:11Z")
> [@Ludy](#): > > The change was explained to me by the lumber starting out at the advertised dimensions, and the loss comes when the wood is planed and finished. > > But I can’t remember who told me that so I could very well be wrong. That’s correct. 2x4 is the _nominal_ dimension of a piece of lumber that is 1 1/2 x 3 1/2 inches. See **Freudian\_Slip** ’s cite. ---
**Author:** ![Crotalus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crotalus/32/41_2.png) [@Crotalus](https://boards.straightdope.com/u/Crotalus)\ **Post date:** [August 21, 2006, 4:32pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/15 "2006-08-21T16:32:00Z")
I’m astounded that you would set out on a substantial building project without having had any experience with lumber. I mean, you’ve apparently never measured a 2 X 4? Never ripped a 2 X 8 or 2 X 10 to create a board of specific width and measured it in the process? You might want to try something a bit less ambitious to familiarize yourself with the materials and the methods before you tackle a deck and stairs. ---
**Author:** ![stretch](https://avatars.discourse-cdn.com/v4/letter/s/a6a055/32.png) [@stretch](https://boards.straightdope.com/u/stretch)\ **Post date:** [August 21, 2006, 4:36pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/16 "2006-08-21T16:36:12Z")
Have you never built anything before? The first thing you learn is that lumber is not 1x or 2x or 3x. Maybe you need a quick tutorial from a girl. 😏 Hemfir is not a special tree, it’s a mixed batch of hemlock and fir stock. Never buy #2 cedar fence boards. KD means kiln-dried. There’s a difference between ground contact and concrete contact pressure-treated woods. Go somewhere were you can pick your own boards. I give up…if you don’t know about the actual size of lumber, there’s too much you probably don’t know. Maybe you should hire a professional. ---
**Author:** ![Crotalus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crotalus/32/41_2.png) [@Crotalus](https://boards.straightdope.com/u/Crotalus)\ **Post date:** [August 21, 2006, 4:38pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/17 "2006-08-21T16:38:49Z")
I should add, it appears you’ve bought pre-cut stringers, which eliminates the most challenging part of building stairs. You can install your nominal 2 X 10 steps at the front edge of the 10" tread are, leaving the gap at the back. Then you can install risers made of 1 X whatever (beware, it’s actually 3/4") or not. Either way. the 2 X 10 will work fine. ---
**Author:** ![Excalibre](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@Excalibre](https://boards.straightdope.com/u/Excalibre)\ **Post date:** [August 21, 2006, 4:49pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/18 "2006-08-21T16:49:35Z")
> [@Scarlett67](#): > > Cripes, I’m a GIRL and even I know that. I’m gay and have zero interest in lumber or any sort of home repairs and I knew it. I thought this was common knowledge. ---
**Author:** ![Monstre](https://avatars.discourse-cdn.com/v4/letter/m/e274bd/32.png) [@Monstre](https://boards.straightdope.com/u/Monstre)\ **Post date:** [August 21, 2006, 4:52pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/19 "2006-08-21T16:52:12Z")
> [@Otto](#): > > Man, if I had a dollar for every time a guy told me that lie… But it would actually come out to just $.93 for each occurrence. ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [August 21, 2006, 5:00pm UTC](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602/20 "2006-08-21T17:00:50Z")
> [@Freudian\_Slip](#): > > The measurement of lumber (“nominal size”) is before planing and shrinkage… > > > [@Scarlett67](#): > > > > Cripes, I’m a GIRL and even I know that. How do women know about shrinkage? 😃 CMC fnord! [Next page](https://boards.straightdope.com/t/when-10-isnt-10-a-word-about-my-lumber/369602.md?page=2)