Wood Question?

[Teken]

I was told many years ago why timber is one size, but is stated another. For the life of me I don't recall why timber is not what it is called.

For instance, if you measure a 2" x 4" it is not in fact 2" x 4" please explain to me why this is the case.

I ask, because my little girl came down to see what Daddy was doing down stairs and making all that racket!! (Building this blasted Queen size bed will be the death of me I swear!)

I told her that I was cutting some 2x4's and some 2x6's . . She walked over grabbed my measuring tape and proceeded to measure the timbers. It clearly shows that each piece is 3.5" x 1.5" and not what I said.

She looked at me all strange, smiled, and said . . . Dad go back to school and ran back up stairs laughing!!

Oh wise one's please inform me, so as I will be able to educate myself and all those around me!

EVIL Teken . . .

 

[Gary S]

If you rough cut wood and then cure it, it shrinks some as it dries. Then you plane it to finish size and it will be smaller than you started with.

 

[PurdueSD]

rough sawn they are 2x4, when planed/sanded they loose a 1/4" per side...

 

[GeorgiaHybrid]

2x4 is rough sawn size, 3 1/2x1 1/2 is finished four sides.

 

[Teken]

So, every piece in my house is 1/2" smaller than it is called? Oh geeese, I better hide the tape now because she's on a measuring rant with my girl friend!

When I posed this question to an American friend, he just yelled back.

Stop using that fracking Canadian tape and it might measure right for once!! Friends, what are they for if not to kick you when you're down and need a answer!!!

Once again, many thanks to one and all for the quick reply!

EVIL Teken . . .

 

[Stuey]

Sheet goods and "hobby boards" are often true to their designated size.

 

[mulepackin]

Sheet goods and "hobby boards" are often true to their designated size.

Except industrial particle board and melamine for countertops and cabinets. They are oversized an inch each dimension. This is to allow for 2 full 24 in. rips,or 2 full 48 in. crosscuts.

 

[back2class]

Yeah, in most older homes the frame lumber is rough sawn and true 2x4. Makes a real PIA situation when remodeling.

 

[ddawg16]

When you buy a 2x4, you are actually getting a 1.5" x 3.5" piece of lumber....

What you are paying for is the rough cut size....after they cut it down you end up with something that is 1/2" less in the two dimnesions.....however, the length will be correct.

So...any sawn lumber is going to be 1/2" less than you expect.....except when it's less than 2"...a 1"x? will be 3/4" x ?

That applies to sawn lumber....

4'x8' sheets of pylwood will be 4'x8'.

Melamine will be a fraction larger...

Just remember....16 is the most importan #.....

 

[RobSmith]

Must be using soft wood that shrinks...Try a nice hard wood. One that blunts the saw. That $hit don't shrink and you have to pre-drill before you nail.

 

[Elkiebob]

Why is the shrinkage passed on to the consumer? Rough cut 1/4 or 1/2 inch bigger, dry it, plane it down to stated size, 2x4. This would make sense to me.

 

[cobymedic]

I am with Back2Class, I have an 80+ year old home. A 2x4 or 2x6 is really 2x4 or 2x6. Makes it a pain to add anything new. Not to mention I have a 2 1/2 diameter tree stump in the basement holding up the house. Looks kind of cool tho, so it is staying and it is solid as can be.

 

[Teken]

I am with Back2Class, I have an 80+ year old home. A 2x4 or 2x6 is really 2x4 or 2x6. Makes it a pain to add anything new. Not to mention I have a 2 1/2 diameter tree stump in the basement holding up the house. Looks kind of cool tho, so it is staying and it is solid as can be.

Personally, I would prefer what you both got in terms of timber in your home. Maybe I am too old school, but I truly believe you should get what you paid for, and what is advertised.

It honestly wouldnt bother me to see rough lumber in joist, beams, etc. 1/2" of anything only adds more strength and long term use and satisfaction for all.

Regards

EVIL Teken . . .

 

[djjsr]

The first time I ever built anything (back in the 50's) it was pretty common to find a finished 2x4 that was 1 5/8" x 3 3/4". I think economics cut it down even further and the building codes didn't argue. I got some cheap studs a while back that were only 1 3/8" and some 3/4" plywood that was 11/16". Like most things these days, they charge you more and give you less.

 

[buening]

Widths less than 8" are 1/2" less than rough cut. Widths 8" and larger are 3/4" less than rough cut, unless you get 6" thickness and larger in which the nominal width goes back to 1/2" less than rough cut width.

 

[stewart]

Ok heres how I heard it!

Back in the good days of lumbering and building houses a sawn piece of wood measured 2" x 4". Strong and perfect for framing. Then some body invents a planer and they run the old 2" x 4" through it. The rough cut guy isn't about to compensate and add more to get less (his mill is set up and all his boys been cutting 2 x 4 since forever) so some ***** *** city boy can have square on two sides smooth timbers. Now the 2 x 4 is somewhat smaller, 2 3/4 x 2 5/8. Not good enough, says the ***** *** city boy, lets plane smooth all 4 sides, now its even smaller 3 1/2 ish x 2 1/2 ish. To hell with all this smoothness and "squareness" I'd like just once to get a 2 x 4 that isn't shaped like a bannana or twisted like a twizzler!

 

[voetsek]

Widths less than 8" are 1/2" less than rough cut. Widths 8" and larger are 3/4" less than rough cut, unless you get 6" thickness and larger in which the nominal width goes back to 1/2" less than rough cut width.

Unfortunately, this isn't necessarily true either, on 2x6 and up I have had variances up to 1" less than rough cut dimensions depending on the plant, section of the nation/world the lumber came from. The russian 2x4's that I have had are up to 1/8" under nominal size sometimes.

It's all in what the plant and planer are set for. It's really irritating that you now have to measure dimensional lumber to make sure it's all the same size. Especially coming from a family that has owned lumber yards for many years.

 

[Teken]

Ok heres how I heard it!

Back in the good days of lumbering and building houses a sawn piece of wood measured 2" x 4". Strong and perfect for framing. Then some body invents a planer and they run the old 2" x 4" through it. The rough cut guy isn't about to compensate and add more to get less (his mill is set up and all his boys been cutting 2 x 4 since forever) so some ***** *** city boy can have square on two sides smooth timbers. Now the 2 x 4 is somewhat smaller, 2 3/4 x 2 5/8. Not good enough, says the ***** *** city boy, lets plane smooth all 4 sides, now its even smaller 3 1/2 ish x 2 1/2 ish. To hell with all this smoothness and "squareness" I'd like just once to get a 2 x 4 that isn't shaped like a bannana or twisted like a twizzler!

Thanks, I really needed that !!

 

[Rickster55]

I'm pretty sure djjsr has it right.

 

[Torque1st]

FWIW, I noticed a number of years back that flat goods seemed to be made in even metric dimensions that approximated the Imperial dimension. That makes that 3/4" plywood 18mm. -Almost always thinner... But then that 3/8" plywood is 10mm.

 

[rwhite692]

Here is some good stuff on the subject:

For convenience, we refer to lumber by its nominal dimensions, which are larger than the actual dimensions. Nominal dimensions traditionally referred to rough lumber, but the size is reduced in drying and planing. Early standards called for rough lumber to be of full nominal dimension, often in the dry condition, but the requirements have decreased through time—the typical 13/16 inches for a finished 1-inch board in the 1910s was reduced by 4% in 1929 and by another 4% in 1956, resulting in the current standard of 3/4 inch.

More:

http://en.wikipedia.org/wiki/Lumber

 

[jonny o]

You think your Quarter Pounder is still a quarter-pound after they melt the ice off and squeeze the fat out of it?

 

[Willy Victor]

Personally, I would prefer what you both got in terms of timber in your home. Maybe I am too old school, but I truly believe you should get what you paid for, and what is advertised.

It honestly wouldnt bother me to see rough lumber in joist, beams, etc. 1/2" of anything only adds more strength and long term use and satisfaction for all.

Regards

EVIL Teken . . .

Termites love tree stumps.


Willy

 

[Teken]

Termites love tree stumps.


Willy

Too funny,

One of the best things about living in the cold aszz north is that there isnt very many critters to speak of. Comimg from NYC, LA, and CA, I can honestly tell you I dont miss the rats - **** roaches - termites - and those huge aszz beetles that make that insane hissing noise!!!

The only thing I can complain about in the summer is the Hulk sized mosquitoe's that bite like freaken sharks . . .

EVIL Teken . . .

 

[krooser]

Simpley put the lumber mill can get more board feet if they cut the lumber smaller and since it still retains enough strength it really isn't a problem.

Back in the 60's a 2X4 was 1 5/8 X 3 3/4 IIRC... I found that out when remodeling a friend's home... now when I need real 2X4's I just run down to one of three local small time lumber mills and order whatever I need... they cut to order.