Grading Dimensional Lumber?

[John Morrison60]

Last fall I had an addition put onto my home with the main purpose being
to add space to my shop.
That worked fine and I love all the spaces that came out of the project.

This last weekend, I worked on putting walls up in the shop. Fun all the way.

However, I discovered that 22 of the 40 2x4 that I had purchased from my
construction lumber company were trash. Totally unusable.
I am going to harangue them some for the low quality, but a portion of the
problem is due to my ignorance.

I just ordered "2x4s to make basement walls".

Should I have ordered a particular grade of lumber?

The carpenters that worked on my project had much better quality lumber
to work with. Mostly straight and not twisted, warped, cupped or barked.

What are the grades of dimensional lumber?
I know how to buy hardwood and plywood, but other than to look at each stick
I do not know how to improve my chances with construction wood.

I would appreciate any hints on ordering and specifying to avoid this problem.
The older I get, I am sure I will be ordering stuff for delivery down the road,
and I feel like I got had this time.
I have some good burning firewood though.

Thanks
John

[David Helm]

Generally order what is known as standard and better (actually a 2 or 1). Don't buy your lumber from a BORG. For small amounts (like you purchased), most lumber yards will let you pick the ones you want.

[Kent A Bathurst]

Dunno what area of the country you are in. Commonly used grades vary by species. SPF Stud grade is typically used in the east for framing. All of the grades have requirements in terms of knot size and amount of wane [what you called "barked"], and other characteristics as well. Stud grade, in particular, focuses on the nailing edges. There will always be some amount of warp, twist, bow, and cup, but it should not be so much that the pieces are unuseable - but that is not the same as saying dead-on perfectly straight.

It is also interesting - and sometimes annoying - to note that the industry's grading rules allow for up to 5% of the pieces in a unit to be "off-grade". Generally speaking, that means that if 95/100 pieces meet the grade rules, the other 5 can be awful, and that unit of lumber is still "on grade". It can get a bit more complicated in the details of how that rule actually gets applied in practice, but for you and me, that explanation suffices. If you extend this line of thinking, then that means that while 50/1000 of the specific pieces are off-grade, the entire lot of 1000 is on grade. Whatcha think happens to those 50? Or, more to the point, if someone has picked through the 1000 and taken their pick of 900 pieces, whatcha think is left? 100 pieces that are "on grade" by definition - and grade-stamped by a licensed grader - but only half of the pieces themselves are on-grade - the other 50 were culled by people picking through the stacks.

You were right in that question is "what grade did you order, what was delivered, and what did you pay for?" Part [a] is unclear - you did not order a specific grade, but you don't mention if they told you what grade they would be sending. Perhaps not, given the way you explain it. So then, part [b] is - what did the paperwork say, and [c] did you pay the correct price for that? If the paperwork said Grade 3 - 4, and you were charged accordingly, then you got what you paid for. OTOH - just as an example, because I don't know your supplier - the guy on the other end of the phone could have figured that you were simply framing in some interior basement walls, that in his mind it did not matter - or you would not know the difference - and he told the yard guys "hey - good opportunity to move out a bunch of those #2 culls we've collected."

I happen to disagree with David on the BORGS - at least to the point that they are used to customers picking through the stacks. If you are ordering sight unseen, though, there is always some risk. I think you have a legitimate cause to discuss the issue with your supplier - depending on what the paperwork says - and tell them "hey - from my end it sure looks like someone was pushing grade on this delivery - what can we do about it?" If they are a reputable operation, they should make some effort to evaluate the lumber, at the least. [And that phrase - "pushing grade" - makes you sound a bit more knowledgeable ].


EDIT - Oh - those carpenters that had much better quality lumber - If they were the ones pulling the material they were going to have to use on the job site, where ya wanna bet they stood on the 5% off-grade pieces in my example above? And, they may well have used a higher grade to begin with. They ain't stupid.

[John Morrison60]

Thanks for the explanations.

I "assumed" that the lumber would be the same grade as what was being delivered for the carpenters.
So I asked the general contractor to make arrangements for the additional wood.
It was an additional cost to the construction cost. I can not locate the invoice that I got for it.
I would guess that the "it's a good time to unload...." was the operable method of operation.
Still learning lessons the hard way.

It will be interesting to see what the dealer has to say.
One factor in the whole process was the number of lumber dealers that have gone
out of business during the recession.
I live in the Detroit area, and this dealer was 45 miles away.

John

[Kent A Bathurst]

John -

In that case, you have an excellent argument on your side - side-by-side comparisons. Seems like your contractor would want to assist in the resolution - not enough business in good ol' "Lizzonia" [ - yeah, I know my way around them parts very well] to risk annoyed customers.

Just curious - what does the grade stamp say on the offending lumber? I'm guessing it is stamped SPF-something.

[Dave Anderson NH]

One other important thing to note John. Never buy your framing lumber of any grade more than a few days before you need it. Store it in the same environment that the lumber yard did. Framing lumber is never dried to less than 15% moisture content and often it is as high as 18-20%. This means that as it sits after having the bands on the skid pack cut, it dries and moves. This is not really important if you use it right away because you are putting it into an assembly and then sheathing it. This stiffens the whole structure and MOSTLY prevents further movement. The reason dry wall nails pop and you occasionally hear movement in floors is that the lumber continues to dry and shrink.

[Jerome Hanby]

Suppliers also get to know their customers. If your builder had the reputation of unloading every piece himself and sending any that weren't acceptable back with the truck to be replaced, then the supplier would know to exercise some caution about what they loaded onto the truck...

[Kent A Bathurst]

.......often it is as high as 18-20%....

IIRC - it should be stamped KD19 or SD19, indicating 19% moisture when it left the mill.........but, like anything else in the arena of lumber grading, there is wiggle room. I think that is 19% +/- 2%. Also, I expounded earlier on the "5% off-grade" components.

Which brings me to my actual point: The grading rules are used to be sure that there is a consistency to the products brought to market. If you have ever been to a modern softwood lumber mill, the technology in use is actually pretty amazing. Computerized scanning of the logs to determine best orientation for cuts, and continued scanning to detemine subsequent cuts-and-yields in terms of width, grade, and length. All of this is determined real-time as compared with current market prices, demand, on-hand inventories + order files, all at the width-grade-length level of granularity. Curved-sawing technology is jaw-dropping - running big, curved logs through high-speed huge circular saws, and pivoting the saw bed in small fractions of seconds to follow the curvature and get straight boards [after drying] out of curved logs - doesn't seem possible until you see it in operation, and each of these machines' price tags easily has two commas. "Small log processors" that take small logs, and at stunnning speeds spit out one single finished 2x4, 2x6, etc. for another example.

And - this is a thin-margin business [at best]. So - if the grade rules say "5% off-grade", and you are shipping lumber that is 4.5% off grade, you are leaving money on the table. Same with 19% +/-2% MC - if you are drying it to 16%, you are - literally - burning money. Your business is at risk.

So those grading rules are very important, because with the advent of this technology over the past 20 years, the well-run operations hit those rules dead-nuts. Before all of this, the "conventional wisdom" was that the humans that were manually grading the boards were working hard to do a good job, but did not want to get their grading license dinged in the unannounced audits by the overseeing compliance organization, and "better" stuff got through.

Slightly off topic, but not entirely: The comments earlier about lumber at the BORGS - Obviously, huge volumes of PT SYP lumber move through them [I am not very familiar with other species that are PT]. They cannot survive if they refuse to let their customers pick through the lumber, even if a not-very-knowledgeable consumer is looking only for "the perfect pieces". So, those racks accumulate culls, as we have all seen. It turns out that, 15 years ago or so, one of the two big guns determined that the one of the biggest reasons for culls was wane. So, they started swinging the big hammer, and, over a period of a couple years, got the supplier industries to introduce an entirely new grade - #2 Prime. That is lumber that meets all of the grade rules for #2, EXCEPT that it has the wane rules for #1. This served to strip out all of the best [ie - least] wane from the #2 SYP family. The remaining stuff meets all of the #2 grade rules, but instead of getting in the mix wane-free, and the almost-no-wane pieces, virtually all of the #2 SYP has right at the max allowable wane. The howls from the construction-based users of #2 SYP continue to this day.

[John Morrison60]

Kent


The BAD lumber is MOSTLY stamped:
" 246 2
NLGA S-P-F"

a few are stamped:
" 112 STUD
NSLB KDHT"



The replacement stuff that I got from the Borg is stamped:

NO. 2
1224 NLGA S-P-F


I hope someone else is learning something with this discussion.
I feel much more capable of getting it right the next time.

Thanks
John

[Kent A Bathurst]

Well, the grade stamps on the bad stuff are fine - my best guess is you got the culls the lumber yard was trying to move out. It's certainly possible that, at the time your order was filled, they happened to be low on stock, and this is all they had at that time.

246, 112, and 1224 are the identifiers for specific lumber mills. Those identifers are assigned by and registered with the supervising grading agency - NGLA and NSLB in these examples.

The "2" and the "STUD" are the lumber grades. For your application, these two grades are interchangeable. The BORG [or any supplier] will generally accept either or both - the market prices on the two are not completely divorced from each other, but a variety of factors cause one or the other to be a bit more or a bit less expensive, or have better or worse availablity, at any given point in time.

SPF is a species - actually, a group of species that all have the same structural characteristics....it stands for Spruce-Pine-Fir.

KDHT means "kiln dried heat treated". The fact that it does not appear on the #2 sticks means nothing - the grade itself includes the MC requirement.

In this case, the KDHT is there for a different purpose. Some years ago - man, memory is a dicey thing - 15 maybe? More? - the international community put in place rules governing the wood products used for packaging. Those products must be "heat treated" to kill any nasties that might be imbedded in the wood. [Remember those nice ash trees that used to be all over SE Michigan?]

There is a specifc definition for what constitutes heat-treating - that memory cell on vacation at the moment also - but it is something along the lines of "it's gotta be heated until the inner temp reaches 140* F, and maintained for 30 minutes" Those are not the correct numbers, but you get the point. This is not the same as meeting the softwood lumber grading rules for moisture content - you can hit those without necessarily meeting the HT regs. And - you can hit the HT regs without getting to 19% MC - consider green oak: pallets and crates are made from "bark and better" grade that are HT but not 19% [industry insider joke - feel free to use it with your supplier, as in "it looks like someone was pushing grade and included some bark & better" - but be careful, they might not have a sense of humor. That line is analgous to looking in the cockpit after a flight, and asking "right seat landing?" - you want to keep moving if you use that line] .

So - the producing mill is certifying those sticks as meeting the HT regs.