Replies

1. 
   oops | Jan 15, 2012 09:08pm | #1

   SYP grading

   Calvin. Is this due to a fallacy in the old grading rules and procedures or is it due to the all the small new growth trees being used today? B.S.

1. 
   calvin | Jan 16, 2012 06:16am | #3

   oops

   I don't know the reason why the studies were undertaken.  I do know that it's been in the works for a while.  Since I'm fresh up and hardly through the first cup I'll have to return later after a bit more study.  That they took 2x4's into consideration first might suggest quicker growth production, I don't know that to be the case.

   I rcvd. the notice in an email and thought it might be an interesting point of discussion.  Hopefully others will know or find out the history and implications and post 'em.

2. 
   DanH | Jan 15, 2012 09:59pm | #2

   Any clue what this means in practical terms?

1. 
   calvin | Jan 16, 2012 06:23am | #4

   Dan

   If in fact the new grading procedures take effect, and the strength of southern pine framing lumber is reduced, then size and spans will have to be redrawn-limiting what can be done with this readily available (here at least) framing lumber.

   Truss plants certainly could have some concerns.  Deck framing here (treated) is pretty much all SP.  While we do see larger framing members in Hem/Fir, the ratings for southern pine have usually been higher so allowable spans greater.

   Beams and headers in home construction would change-a 20% lower rating isn't small change.

   Could be a boon for engineered lumber.

1. 
   DanH | Jan 16, 2012 07:47am | #5

   Of course, houses haven't been falling down.  Would this affect standard 2x framing of a simple 2K sq ft home with no fancy long spans, etc?

1. 
   calvin | Jan 16, 2012 08:30am | #6

   Below, is a quote from the end of the meeting's findings.

   "Although given the facts, circumstances and controlling authority of this particular matter, the Board did not approve design values for the other sizes and grades and has recommended a future effective date

   , it cautions all interested parties to take note of all available information in making design decisions in the interim. The values in the SPIB proposal represent approximately a 25-30% reduction. Many of the critics of the proposal acknowledged that some reductions were in order, albeit the magnitude of those reductions was disputed. All design professionals are advised in the strongest terms by the Board to evaluate this information in formulating their designs in the interim period.

   The Board also wishes to commend the Southern Pine Inspection Bureau. The original testing did not contemplate the results that ensued nor was it designed to be a full matrix. Faced with sizable indicated reductions, SPIB felt obliged to expand the scope of its recommendations to other sizes and grades in an abundance of caution and in furtherance of its stewardship of the Southern Pine rules.

   Dated: January 11, 2012 "

   This suggests that any near future designs plan and consider according to the findings to date.

   And yes, this would affect dwellings.  As we know, the span values listed in most publications are considered the minimum.  So, with a reduction in strength value comes I'm going to assume a rewriting of allowable spans using southern pine.  What drop percentage wise I cannot say.

3. 
   BossHog | Jan 16, 2012 07:30pm | #7

   I don't claim to be an expert on this, but have been following the situation pretty closely. I'll tell ya what I think and what I know, and try to keep the 2 separate.

   From what I can tell, someone began question the values of 2x4 #2 back in 2010. The SPIB at some point decided to do some testing to see if there was a problem. They rushed the testing through and proposed immediately reducing some of the design values of all sizes and grade of SYP by 20 to 35%. 

   The testing methods and timing have come under intense scrutiny. For instance - Prior to summer they did extensively non-destructive testing. For the purposes of this study they turned to 100% destructive testing. They came up with entirely different values, but (as far as I can tell) made no effort to figure out which kind of testing they should actually be doing or what it would mean.

   Some smaller mills have complained that they think they're trying to switch production to mills that produce MSR or MEL lumber. (Those grades are not affected)   Others have protested that not enough time was given to study the results. Others said it was foolish to change the values for all lumber when they had only completed testing for 2x4#2.

   Last week the ALSC decided to go ahead and reduce the values for #2 SYP 2x4s.  The new values take effect June 1st. 

   After testing is completed on other sizes and grades of SYP lumber those values will probably be adjusted.  I figure that will happen late this year or early next year.

   So far I haven't see a credible explanation as to why the lumber may be different and actually require adjustments to the design values. I've heard speculation.  But nothing that I feel explains it adequately.

   Someone asked what this will mean.  The main thing for now will be the design of roof trusses that use 2x4 #2.  (In Illinois, that's almost every truss plant)  Things that used to work won't fly any more.  The lumber grade or size will have to be increased. Some truss plants may switch to MSR lumber instead of #2.  Others may buy high grades of SPF lumber. No one knows how exactly it will play out. The only safe bet is that it will make trusses more expensive. Something the housing industry doesn't need right now.

   If they reduce the values of other sizes and grades, floor joist spans will be reduced. A 2x12 that used to span 17' may only span 16'.  There's no way to know what exactly may happen, since they haven't completed testing yet.

   Off the top of my hear I don't think the values will take to much of a hit on the larger sizes. The last time they changed SYP lumber values (about 1990) the numbers of the wider widths took a big hit. I don't think they'll go down much more. But that's just a guess.

    

1. 
   calvin | Jan 16, 2012 08:51pm | #8

   Thanks

   Glad you found this.

   Hope to hear from some more with experience like you have.  Me?  I just follow directions and nail it together.  Hardly a person to offer much in the line of information.

2. 
   calvin | Jan 17, 2012 08:06am | #9

   ron

   I've seen it mentioned that this could expand into redrawing the gradings of other species of wood as well.  Any information from your suppliers or associations on that?

   thanks

1. 
   BossHog | Jan 18, 2012 06:54am | #10

   "I've seen it mentioned that

   "I've seen it mentioned that this could expand into redrawing the gradings of other species of wood as well."

   They're already working on testing for Hem-Fir and Doug Fir. But they're just in the begining stages of testing, so it may be a year or two before anything changes.

   BTW - This wil not change the lumber grades. #2 lumber will still be #2 lumber. But the #2 lumber will have lower design values.