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Question regarding use of rough sawn lumber for home construction

Started by brdmkr, August 17, 2005, 09:14:42 AM

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DonE911

Hey Arkansawyer

Ever have anyone question your stamp? Inspector or whomever.

brdmkr

Don

Thanks for those sites.  They are really helpful.   I don't mean to imply that I expect trouble from the inspector.  The fact is, I don't know him and haven't really asked others their opinion.   I am sure he will be reasonable and a decent fellow (since if he was trouble I would have heard that, bad experiences travel fast).   I just know that what I want to do may be pushing the envelope.  As DanG said earlier, I likely will purchase wood for framing.   However, if I can gather enough knowledge to ensure my own stuff is of good quality and can convince the inspector of that, all the better.  I am not in a hurry and won't begin building for some time, so I have time to learn :P.

I suppose my most pressing concern is knowing what pushes the envelope (framing lumber) and what is generally acceptable (I am hoping that at least flooring, siding, and paneling fit into this category).   It is just a bit frustrating that this information does not appear to be online.  I suppose that I could call the inspector to inquire about these items and then meet with him later to discuss framing materials.
Lucas 618  Mahindra 4110, FEL and pallet forks, some cant hooks, and a dose of want-to

Buzz-sawyer

I just wanted to comment
Wood like xotton wood, sycamore, elm ash...are all common up here, there is NO SYP.
All these woods are vastly superior to white pine in load bearing properties and durability.
Yet in many places they arent even considered for framming material....this is not an intelligent or practacle approach.
So much is turned into pallets and blocking that could build homes 2x as strong!!
    HEAR THAT BLADE SING!

Don P

Buzz,
We're in the same boat here, I hate to see good wood go into pallets and Lowes selling junk. One man I was talking to the other day told me that the red maple isn't even worth pulling out of the woods right now between the sawmill prices and fuel cost, its DanG strong wood!

It's been a rainy morning so I've been making a set of span tables for poplar at our design loads. Won't work in other areas with other snow loads etc. but hopefully will show that it can and should be done. I've been e-mailing the top folks in the field and as far as I can find out this has never been done, engineering in nontypical framing species has been done on a case by case basis...we gotta do sumthin bout that. I'll send the links to the state folks, the TP engineer and a few Docs. Hoping to get approval to hand some info out at the class on our local woods. Approval to use them is one thing, you need the allowable loadings and spans in an easily understood format to accompany it. Got a little more cyphering to do, I'll ask you all to take a gander when its up and see if it makes sense.

brdmkr;
I understand your frustration about the info. The library is one place, and don't forget interlibrary loan. When you do have your sit down with the inspector, he will probably be one of the nicest guys you could hope to meet, ours are. Our conversations usually end up with them reaching for and flipping through well worn books at a rapid and knowing pace and xeroxing info for me to take home and study, they get top notch training and are there to help.

The ICC grading requirement only applies to structural elements, generally framing and sheathing, state or local add on's could ask for more I guess, haven't run into that personally. What the code is trying to ensure is a frame and skin that will bear all anticipated imposed loads without failing, after that "decorating" the structure is much less stringently regulated. Its one of those things that's easy to see both sides of.

I think learning all this stuff is good whether you directly use it or not, it makes me understand why we do things the way we do. The more you know the more critically you can look at a situation...I've caught architects and engineers oopses and been able to quietly and confidently correct them. We have a saying "Good carpenter would fix that and never say a thing"  :-X ;D. It can also make you overanalyze a dog house  :D.

Buzz-sawyer

Don
you need the allowable loadings and spans in an easily understood format to accompany it

I have tables like that if you would like I can scan them and upload?
    HEAR THAT BLADE SING!

brdmkr

I look at all of this as one big adventure.  I really enjoy jumping into something that I know nothing about and then learning as much as I can.  I think it helps me be more well rounded.  No wait, the dinner table does that :D

I can't believe that I didn't think about the library.  Believe it or not, I read a great deal, but I haven't checked out a book from the library in years.  I think I'll see if I can get my hands on a copy of Georgia's buildling codes.   If I can ensure that I can use my own flooring, paneling, and siding I'll be plenty happy.  I'll then focus on framing lumber.

Lucas 618  Mahindra 4110, FEL and pallet forks, some cant hooks, and a dose of want-to

Don P

Readin and feedin makes a body well rounded  ;D

Buzz, post away  8)

I just uploaded this mornings efforts, have a look,
http://www.ls.net/~windyhill/Calcs/poplarspans.htm


Larry

Quote from: Don P on August 18, 2005, 12:55:27 PM
I've been e-mailing the top folks in the field and as far as I can find out this has never been done, engineering in nontypical framing species has been done on a case by case basis...we gotta do sumthin bout that. I'll send the links to the state folks, the TP engineer and a few Docs. Hoping to get approval to hand some info out at the class on our local woods. Approval to use them is one thing, you need the allowable loadings and spans in an easily understood format to accompany it. Got a little more cyphering to do, I'll ask you all to take a gander when its up and see if it makes sense.


Don, looks good to me...thanks for sharing.  I would imagine that took a lot of work. 8) 8)   

I do have couple of questions.  Where did you get your E values and even broke down by grade?  Buzz, do you have span tables for stuff like cottonwood?  I get the E value for cottonwood than use a softwood span table of a species with the same E.  Not for sure if it is valid or not, but so far the cows don't appear worried. :D

Larry, making useful and beautiful things out of the most environmental friendly material on the planet.

We need to insure our customers understand the importance of our craft.

Frank_Pender

Well, well, persistance is paying off for some of us here in Oregon.  There is a blue ribbon group of us folks gathering at the end of August/first of September to look into the idea of establishing a program where small independent sawmillers can take economically designed classes and deal with the issue of getting their lumber graded.   Another thought is that of acquiring a grader that have them become a circuit rider here in the Willamette Valley.   I will my bestest to keep everyone informed of our progress and direction of action.

   As I have said before the big boys association check folks want around $375 an hour plus mileage for grading. 
Frank Pender

Don P

 8) 8)
Good work Frank, do keep us posted on your progress. Its good for us to keep telling of successes and failures, it'll hopefully help us all get something going. Bureacracy doesn't have a habit of lightening up on its own  ::).

Larry, I used the numbers from the National Design Specification for Wood Construction available from the AF&PA kinda spendy unless you want ALOT of info on wood and timber, joint formulas...
It is the reference the code uses for that type of info.
The table wasn't to bad to make, next one should only take an hour or 2. Dad's old codebook had a span table made up of Fb/E numbers so if you apply the NDS #'s it can spit out that table pretty quick. It was about useless to the average carpenter, I wanted something easier to use. I did go back and work the math on several spans just to double check, it seemed fine.  I'll let some pro's give the nod before I go whole hog. Hoping Buzz has something readymade that would be waaaay cool.

If any of you need design values, formulas or whatever that might be in the NDS books just shout.

Cottonwood;
SS-Fb=875,E=1.2,Fv=125,Fc(perp)=320...Fv(shear) &Fc(crushing perpendicular to grain) remain the same throughout the grades.
#1-Fb=625,E=1.2
#2-Fb=625, E=1.1
#3-Fb=350, E=1
Stud-Fb=475, E=1
Construction-Fb=700, E=1
Standard-Fb=400,E=.9
Utility-Fb=175, E=.9

Quick lesson to those going, What???
A joist or rafter can fail in one of 3 ways (typically)
1..in bending, usually a long span with a heavy load will snap somewhere around midpoint starting with the extrem outermost bottom fibers being torn apart. Extreme(outermost)Fiberstress in Bending...Fb. The allowable Fb number tells you how much load is allowed per square inch on this extreme fiber.

2..in shear, usually this failure happens in a short, very heavily loaded timber. Bend a deck of cards and watch the "fibers" slide past one another. In a joist that would be a shear failure, your one deep beam just became 2 or more wimpy not so deep beams. Fv gives allowable shear load per square inch.

3..excessive deflection, this one isn't really a failure, its telling you how much the timber will bend or bounce under load. E, or Modulus of Elasticity tells how "springy" a type of wood is. More often than not this is the controlling calculation in specifying a joist or rafter. The thing often isn't in danger of breaking, but it sure looks and feels bad. Think bouncy farmhouse floor or swayback ridge.

I added the compression perpendicular to grain because when you header or put a post under a girder you don't want to crush that beam on the post top. That number tells how much load each square inch of the beam end can support safely without crushing...calculate the load, divide by the allowable value and it gives the number of square inches the post top needs to be.

NDS also gives Ft, tension parallell to grain, like a truss bottom chord, and Fc parallel to grain (log on log for one) if anyone needs those #'s.


Chris Burchfield

And this is what the book says'

2003 Edition International Building Code, Section 2303.1.1 Lumber. Lumber used for load-supporting purposes, including end-jointed or edge-gluded lumber, machine stress-rated or machinge evaluated lumber, shall be identified by the grade mark of a lumber grading or inspection agency that has been approved by an accreditation body that complies with DOC PS 20 or equivalent. Grading practices and identification shall comply with rules published by an agency approved in accordance with the procedures of DOC PS 20 or equivalent procedures. In lieu of a grade mark on the material, a certificate of inspection as to species and grade issued by a lumber-grading or inspection agency meeting the requirements of this section is permitted to be accepted for precut, remanufactured or rough-sawn lumber, and for sizes larger than 3 inches nominal thickness.

"DOC PS 20" is a "Voluntary Product Standard," when I looked it up on Google. 656 pages of the IBC is more than I care to relate here and contend with Copy Right Standards. Durable Wood is referenced in conjunction with treated wood, like the cap plate around the slab or for use above a crawl space on a conventional foundation but, "durable wood" is not defined. The Southern Building Code would allow Red Wood or Bois De Arc (?) in lieu of treated.

Section 2304.10 Heavy timber construction.Columns, Floor framing Roof framing are addressed with words like "properly designed steel or iron caps, wth pintles and base plates, yada yada yada. Sorry folks but I'm not an Engineer, who's position I truly respect. Anything specific, I'll be glad to try and look it up.
Woodmizer LT40SH W/Command Control; 51HP Cat, Memphis TN.

brdmkr

Chris,

Thanks for the paragraph.  If I read it correctly, it seems that using your own rough sawn wood would be acceptable if you paid someone to grade it.  I was also glad to see that it specifically referenced 'load bearing'.  That encourages me, thinking that flooring, paneling and siding might be OK without grading.

Lucas 618  Mahindra 4110, FEL and pallet forks, some cant hooks, and a dose of want-to

ARKANSAWYER

  Nope! No one has ever rejected my stamp.  As by DOC PS 20 I have graded my lumber to meet the standards of ALSR and those by the SPIB which govern my wood.  The SPIB is a non-profit organization that was formed by the "BIG BOYS"  to take the rules of ALSR and use them to govern and control the "little guys".  I read and read and never found a law that said that the SPIB was the Ruler of the Land by the Government.  It all goes back to DOC PS 20.  SPIB even states "The grading of lumber cannot be considered an exact science..." and has no libility in a failed member that was stamped under their codes.  There are rules for green and air dried lumber as well as unfinished.  Meet these rules and your lumber is fit to be used.
   THE STAMP ONLY TELLS the TYPE OF WOOD, GRADE, THE MILL THAT SAWED OR GRADED IT AND THE one of seven Inspection Bureau's that set up the rules and charges for services.
  What they are doing in VA is great.   If all of us keep plugging away at our state boys we can make some changes.  Talking to your local inspectors in a nice and informitave way is the way to go.  Here in the County there are no rules other then common sense.  In town they have some rules but most are for elec and plumbing.  Most can see a good board when it is in front of them. 
  My stamp is good by DOC PS 20 and I follow all grade rules.  I would welcome a chance to attend school for grading but the SPIB just blew me off.  I guess if we get more states to accept us then they will open their arms and welcome us so they can control us.
  Learn and follow the rules and stamp your own lumber.  If some one challenges your grade have them bring in an inspector with the understanding loser pays the bill.   Read your building codes and learn what is asked for and most of the time you can meet it.  I never could find a federal law that stated that SSMU could not form and that the other non-profit  bureaus were all there could be.
  Hardwoods do not really have a structial grading system.  Most of what I have seen in timber framing refers to the grade of the face like in 4/4 lumber.  So much clear and no loose knots or rot.  There are charts for spans on most hardwoods like oak, ash , popular and others. 

  If you went to a box store with a grade book and graded their pile I would be willing to bet that more then 5% would not meet grade.  I have gotten several bundels when I built houses and would return 1/3 of it.  I have customers who will not buy lumber at the lumber yard any more because they like my boards better.  Soon I will be able to meet their needs all the time. 
ARKANSAWYER

brdmkr

Quote from: Chris Burchfield on August 18, 2005, 07:31:18 PM
shall be identified by the grade mark of a lumber grading or inspection agency that has been approved by an accreditation body that complies with DOC PS 20 or equivalent.


Quote from: ARKANSAWYER on August 19, 2005, 09:43:00 AM
It all goes back to DOC PS 20. SPIB even states "The grading of lumber cannot be considered an exact science..." and has no libility in a failed member that was stamped under their codes. There are rules for green and air dried lumber as well as unfinished. Meet these rules and your lumber is fit to be used.

What is to stop a someone from forming a nonprofit and stating that they follow DOC PS 20?   Members could pay a nominal fee for training that could be provided by a recognized professional.  Once trained, the nonprofit could issue a stamp.

Lucas 618  Mahindra 4110, FEL and pallet forks, some cant hooks, and a dose of want-to

Zeke

Quote from: brdmkr on August 19, 2005, 11:28:06 AM
What is to stop a someone from forming a nonprofit and stating that they follow DOC PS 20?   Members could pay a nominal fee for training that could be provided by a recognized professional.  Once trained, the nonprofit could issue a stamp.

I think that is the question we would all like answered.  I would think membership in something like this would be worth one or two hundred dollars a year. Keeping training costs low would be the biggest problem. How about a Forestry Forum stamp? I would think many of the sponsors of the Forestry Forum would be willing to support such a group. Their business would benefit from it being easier to get lumber graded.

Zeke

Buzz-sawyer

    HEAR THAT BLADE SING!

Don P

"When a DOC Voluntary Product Standard is made a part of a legal document, such as a sales contract or code, compliance with the standard is enforceable."

2.1 Accreditation—Procedure by which an authorita-tive
body gives formal recognition that a body or per-son
is competent to carry out specific tasks.
6.2.6]

"Producers, distributors, users, consumers, and other
interested groups contribute to the establishment of
DOC Voluntary Product Standards. These groups
initiate and participate in the development of the
standards, provide technical or other counsel as appropriate, promote the use of and support for the standards,
and assist in keeping them current with respect
to advancing technology and marketing practices."
Office of Standards Services, National Institute of
Standards and Technology, Gaithersburg, MD 20899-
2150.


This is a link to SPIB's visually graded services web page;
http://www.spib.org/vglumber.shtml?/lumberservices.
Arky, how many sawyers could you get together for 4 days?
If they won't allow you training, TP would probably be glad to bring a program to you. Their stamp is on as much SYP as SPIB's here, they let me train there and took my money happily. I did find myself in the HD that was beside my motel while I was at the grading school. An armload of their 2x4's came into the class the next day.  :D

I think we should be trained...so should they. Wood does just happen to be the major structural element in most construction...grading education oughta be readily available to anyone pretty easily. Small producers and inspectors should have the same training as the "big boys". If the inspector asks for a judgement call, then third party auditing by one of the grading agencies could be called to come in.  If everyone is trained I kinda think its a non-issue.

All stress grading for knots is done the same in concept from what I was taught. It doesn't really matter the species or size, how you look at a piece of wood is the same, look inside the piece of wood as you grade. Find the worst defect. Almost all branches stem from the heart.  You visualize the knot displacement within the cross section of the piece of wood. Looking at all 4 faces, figuring out where the pith was. Knowing where the pith was in relation to the knots you see on any face. You can see where each branch is going, how much clear straight grained wood remains around the stick of weak branch that either passes through the timber or stops at the pith within it. Based on how much good wood is displaced by the knots, their size and location, according to the grade rules for that wood, a grade for the knots in the piece can be determined. If thats the worst defect that piece of wood has, that's the grade. The old timers rule of thumb is quarter, third , half ...#1,#2,#3.

To make a span table for dimensional lumber or to calculate a single beam's load and span, you take the grade (the proportion of good wood you have) and species of wood and look up the allowable design values. Those variables account for the different strength properties of each species. If you look at the design values for the different grades in every species, those strength values drop by about 1/4, 1/3, 1/2...basically how you look into wood and grade is the same, the design values account for the differences in size or species.

Anyone can petition the board of review of ALSC to become a grading agency, FF or SSMU could petition for that, I think it costs about $100,000 by the time its all done and said from what one biased source told me. There are several agencies that are former employees of other agencies who went out on their own...so it can be done, might be worth checking into. For small mills self grading and educated inspectors is the way I'd like to see it go, this isn't rocket science.

If anyone has some kind of span tables for appalachian hardwoods, I'd sure like to have some. I'm in a real weak position there, "official" hardwood span tables, graderules anything like that would go a real long way.



Don P

The regional head of the inspectors did question the authorship of my table, and asked if something was available from AFPA or AWPA

I did find this span calculator online at the AFPA website. It does put out longer spans than my table.
http://www.awc.org/calculators/span/calc/timbercalcstyle.asp

I was just using base design values, trying to keep it simple. The adjustment factors it uses do bump up the allowable spans quite a bit  8).

I was thinking back and did mis-speak. The reason we are only having a 1 day class here is that TP will only do a 1 day "introduction to lumber grading" on the road. The 4 day class is only available at their site in GA. The other time is more in depth knot and defect lessons, a tour of the lab and seeing how samples get tested (and breaking a few) and being tested at the end. I'll post how the 1 day class goes. We will end up with the same literature (rule books and pocket guides) as the 4 day class. I'll try to find out what this whole deal cost the state. If it goes well maybe have TP do a FF class sometime? Its a shame this wasn't part of shop class or drafting class in high school.

DanG

Not sure if Don P has already posted this link, so I'll put it up again.  Looks like some pretty good tables to keep handy.

http://www.southernpine.com/spantables.shtml
"I don't feel like an old man.  I feel like a young man who has something wrong with him."  Dick Cavett
"Beat not thy sword into a plowshare, rather beat the sword of thine enemy into a plowshare."

Frank_Pender

I will be meeting near the end of Sept. with the folks I spoke of earlier.  I would appreciate it if one and all would send me short specific ideas on how something might be established.   Personal message, or bettte yet direct e-mail me with ideas and then I can print them off and have them available when I attend the first meeting.

    thank you,   in advance. 8)
Frank Pender

beenthere

Can someone venture to put up an objective as to what is the desire (need)?

This thread started with sawing lumber for ones own home. Is that still the intent on what might be 'established'?

Or is it now establishing another 'agency' to grade lumber for construction use and sell it in competition with the lumber yards including the box stores, so then consideration of how to compete against the established agencies is needed.

south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Fla._Deadheader


Little guys would find it VERY tough to compete with the box stores. The gist of the latter part of this thread is to help sawmill folks to get to use their own lumber for Home structural purposes, including BEAMS that the box stores don't handle.

  If I was stayin in the US, I would get involved BIG TIME. The present situation STINKS.
All truth passes through three stages:
   First, it is ridiculed;
   Second, it is violently opposed; and
   Third, it is accepted as self-evident.

-- Arthur Schopenhauer (1788-1860)

Don P

I hope that isn't the reason you're leaving Harold, this is still about the best place I've seen   ;D

QuoteThis thread started with sawing lumber for ones own home
I think that was before I hijacked it  :-[...sorry guys, you can sure tell when I got a bee in my bonnet  ::)

This link shows how NH is doing it, sounds reasonable to me
http://www.gencourt.state.nh.us/rsa/html/XL/434/434-59.htm

Notice that it references DOC PS20-70. I think we're up to PS20-95 or something close, that thing keeps changing slightly too. We do have input that NIST listens to.

Fla._Deadheader


DonP, I happen to agree with you. Hijacking a thread occasionally, for a good cause, is a GOOD thing, maybe  ::) ;D

  It's getting very difficult to afford to live in Florida. If I had some rich relatives, or was 20 years younger, I would probably stay.

  I've been known to speak my mind a time or two.  ::) ::) :D :D
All truth passes through three stages:
   First, it is ridiculed;
   Second, it is violently opposed; and
   Third, it is accepted as self-evident.

-- Arthur Schopenhauer (1788-1860)

brdmkr

Don

NH seems to have a law that is reasonable.  My primary interest is in being able to use my own lumber in my house.  I still have not had time to investigate what is acceptable and what is not in the state of GA.

However, the thread does seem to have take a different direction.  I think that the points that you and others have made are excellent.  I encourage you to do what you can.  Personally, I think graders should be certified and subject to losing their license if they are not honest and consistently able to grade accurately.  They should not be required to be fastened at the hip to a mill and their grade should suffice to meet the requirements of buildling codes.  I even think that continuing education requirements could be placed on graders.  Mills could have a stamp identifying the mill.  The grader could stamp as to species and grade along with some ID that is unique to the grader.

Of course, I admit that I don't know much in this area. (drastic understatement).  I do think the current system is not fair for smaller mills.

My .02 ( and it may not be worth that :o)
Lucas 618  Mahindra 4110, FEL and pallet forks, some cant hooks, and a dose of want-to

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