I called Home Depot to reserve some wood. This is my exact requirement: 2" x 9/2" x 8ft.
I told them over the phone many times
"I am calling to make sure if you have four 2 inch times 9 inch divided by 2 inch times 8 feet board."
and yet they don't seem to understand, and they want me to go there and talk to them. What am I doing wrong?
How am I supposed to pronounce this so it is easy for the workers to understand?
See also How do you pronounce 2×4 (board)
As in linked question you say × as "by"
The fraction 9/2 in this context is never read as "nine divided by two" but as "four point five" or "four and a half"
So the 2" x 9/2" x 8ft is "two-inch by four-and-a-half-inch by eight-foot"
This is not a board, its a post, or a length of timber.
I want to buy some timber, Do you have two inch by four point five inch posts. 8 feet long. It doesn't need to be treated or planed.
In fact it is best to take this step by step engaging in conversation
I want to buy some timber.
Ok, are you looking for treated wood for the garden
No, it is to replace some interior studwork.
Okay what size do you need?
two inch by four point five inch.
Yes we have that, how long?
eight foot.
By breaking it down you get time for the other person to process, to ask the questions that they think are important, to check at each stage.
After reading all the excellent answers, I was able to clearly communicate what I wanted with the Home Depot sales person.
I had to go there though (they were not picking up my phone call). I told them I wanted some board to build a heavy-bag stand.
Jake: I'll take you to where we keep our dimensional lumber. What did you have in mind?
Me: Well, I need four posts (as James K said in his answer). I was hoping to get two inches by four point five inches and eight feet long. (Yes, I couldn't say this the right way.)
Jake: Four point five?? You will have to take four two-by-sixes and then plane them down.
Me: Okay wait, can you first tell me the most accurate way to say this, like the measurement?
Jake: Oh, yes, was it you who called in, yeah sorry about that. So you wanna say the nominal size first which is basically the nominal width and the depth of the lumber. So you would say "two-by-six" first and then the length which is the actual size. So a "two-by-six" is actually "one-and-a-half-inches by five-and-a-half-inches".
Me: Right. But how would you say the decimal if you had to for the nominal size?
Jake: We don't usually use decimals like that but if I had to say it, I would probably say "two by four-and-a-half-inches".
To summarize, the correct way to say this is to break the measurement down. First say the nominal size of the width and the depth, and then say the actual length.
I am wondering if you guys have two by four-and-a-half inches dimensional lumbers (or posts or studs). They need to be 8 feet long. And I need four of them.
You would pronounce it as 2 inches by 4 and a half inches by 8 feet.
Nobody in the building trade says '9/2' or 'nine halves', and saying 'board' can also be confusing, but a 'plank' indicates it is a length of timber. A thinner plank might sometimes be called a board (e.g. floor boards, skirting boards), but a board can also be a sheet such as fibreboard or chipboard.
It's a good idea to separate the quantity (a length here) from the dimensions too:
I want an 8 foot length of 2 by 4-and-a-half.
The clerk was right to point out that if you need 4.5" you'll need to get a nominal 2x6, which is really only 5.5" wide, and cut an inch off it. (A lengthwise cut like this is called a "rip", so you could ask the shop if they could "rip" it down to exactly 4 and a half. I don't think you'd use a planer take a full inch off, planers are for removing smaller amounts. Many lumberyards can rip boards for you; I've seen them rip 2x4's to make up an order for 2x2's.)
But the other dimension is actually harder. That 2x6 is only 1-1/2" thick, so if your project needs a full 2" in that dimension, you're half an inch shy. And the average big-box store may not have anything in stock thicker than the nominal 2". In modern construction, posts, beams, sills and other thick components are likely to be made up of several "two-by" boards glued and nailed together--or special-ordered "engineered lumber" which is a composite of wood and glue. Even if you're matching the size of studs in older homes, which may have been exactly 2" by 4", it's only the 4" direction that's important, because it's thickness of the wall. Nobody cares if the stud is a little thinner in the other direction. This may be why the clerk only paid attention to the 4-1/2" direction, and ignored the 2".
Specialty lumberyards might have 4x6s. You could phone some and say "Do you have 8-foot lumber that you could rip for me down to finish size exactly 2 inches by 4 and a half" and see what they say. ("Finish size" is a common way to say the actual measured size of a finished product.) You're definitely getting into a specialty market.
At risk of re-framing the question, what most folks would do is design their project from the beginning using the standard dimensions that will be in stock: 2x4's, 2x6's, 4x4's, and so forth, all of which being slightly smaller than what the numbers will suggest.
