logs to lumber question

[Donn Hewes]

I am about to order two loads of larch logs to have friend mill here for my barn this fall. Here is my question. If I want 12,000 BF of lumber how many BF of logs should I order. I am sure the answer depends some on the quality and type of logs, but I am looking for any suggestions. I might guess and then leave a second layer of flooring to mill later. That way if I have too many logs to begin with I can have it cut into flooring.

[Rick Alger]

It also depends on which log scale is used, how good the sawyer is, what the saw kerf is, what the actual dimensions are vs nominal (such as do you saw 1 3/4 x 8 or full 2 x 8 ) , and whether you saw for full recovery or have a cut list that doesn’t include a lot of 1×4’s.

With the International scale we got from 5 to 20% overage sawing for full recovery on a Lane #1 circular saw with a 3/8 kerf and an experienced sawyer.

[Rick Alger]

Oops, forgot to answer the question. I think you’d best get 12mbf or close thereto. Your sawyer will probably have some good advice on this.

On another note, if this is what some of us call Tamarack, it’s a good idea to build while the wood is still green. When it dries it tends to twist, and it’s very hard to nail. Not the kind of wood I would stockpile.

[Does’ Leap]

I usually figure adding 20% to the log foot scale (international) to get my desired board footage on a thin kerf bandsaw mill. I would add or subtract from that percentage depending on the quality of the logs. I would rather have a little extra lumber at the end compared with running short.

George

[Donn Hewes]

Thanks Rick and George, I am not sure if this Larch is the same as your Tamarack. I suspect it is European Larch, as it was all planted in plantations here by the CCC. Your advice about using it green may still be true though. I will need to ask a couple people about that. It would be nice to dry it some as it is heavy.

[Does’ Leap]

At least around here, Larch and Tamarack are considered the same tree.

George

[Ed Thayer]

Don,

Our thin kerf 1/8″ band mill will typically yield 20 to 25 percent over international scale. As described above, straight logs will yeild better then curled ones. You should be fine buying what you estimate for your project.

Good luck.

Ed

[Carl Russell]

I will second what others have said.

The only caveat I will add is that the dimension of the desired product will also affect your needed scale. For example if you are cutting 8×8’s you will need to have logs 11″ top end or larger. Those logs will scale far more than the stack of 8×8’s because of the side boards.

This winter I cut 25 Mbf of logs to get 17mbf of 8×8 lumber. Of course there is a lot of extra lumber that is useful, just don’t think it is a straight figure. If you get a bunch of logs 8″ top end, and you are looking for 2×6’s, you won’t get many.

You really should custom order your logs from the stump to match your lumber list….. unless it is just a simple stack of 2×4’s you’re looking for.

If you want to share your lumber list with me I could give you a closer figure.

In fact share it here if that suits you.

Carl

[Donn Hewes]

Carl, That is a good idea, I will try to add that tonight. Just for interest – no one need put too much time into it. I know my list is almost entirely 2 x 6 and 2 x 8. and long. These will require a consistently good log. I have talked with the person I plan to buy from once, but he mentioned I will have to “work with what I get”. He said he was getting into better trees later in July. I am thinking I will try to order logs with a minimum Dia. don’t know if he wants to hear that. Small logs will not do me much good. I guess I do need 2 x 4 for roof purlins.

[Carl Russell]

So a few more thoughts. One thing to remember is that the stick scale on a log, regardless of the Rule used (International 1/4″, Doyle, Scribner, or Vermont), will ALWAYS be 15%-20% under actual board tally. These Rules were developed to provide consistency in commerce, but are still used by buyers who will not benefit from under-scale, or even exact scale. The sawmiller must have a guaranteed overrun to deal with inconsistencies, defects, and production inefficiencies.

I have gotten as high as 30% over-run with my Woodmizer without trying very hard. Either way, that will not make an 8″ board come out of an 8″ tree…..

If you are looking for 2×6’s and 2×8’s, the most efficient logs to buy will make a cant that can be sawed into three 2×6’s, or 4 2×8’s or more. So the minimum TED, inside the slab, for 2×6’s would be the diagonal measurement across that cant, including kerf. 6 1/4″x 6″ = 9″ or 8 3/8″ x 8″= 11.5″ …..

It is time consuming for a logger to custom cut logs, but the truth is that if you don’t get what you need it will cost you more in the long run. If you tell him you will take woods run of everything it takes to make your minimum it will be much more acceptable to him I’m sure, especially with Larch. This is where the extra volume came from during my winter job. We had to cut a certain number of trees to get the 8×8’s, and there were a lot of extra logs that had to be harvested to make that work.

It will be well worth the effort to figure out in advance what he needs from you to get what you need from him…… your sawyer will be much happier too.

Of course this is what I do, so I get really detailed as I want to be as proficient as possible. You may be able to work with a more relaxed methodology.

Carl

[Donn Hewes]

Here is the material list I have been working on. I didn’t post it here in the hopes that anyone would spend much time working on it, but I thought folks might find it interesting. I haven’t ordered logs yet but am just about ready to do that. Still lots of work to do for a Nov 4th barn raising. There are somethings on here that I already plan to change a little.

Hay barn material list 36’ x 60’ 2160 sf.

Foundation: 20 sonotubes, concrete, drainage

Metal roofing 22.5’ x 2 sides x 63’ = 2835 sf.

Plates for sonotubes. Black Locust 2 x 6, 2’

Main beams: ash 10” x 10” 16 – 15’ owner
Rim joist 2 x 8 8 – 15’ 160 bf
Floor joist: 2 x 8 154 – 12.6’ (16” oc + 16) 2581 bf

Wall studs 2 x 6 12 – 15’ (8’ oc) 180 bf
Wall Bracing 2 x 6 24 – 18’ 432 bf
Wall Purlins 2 x 4 36 – 15’ 356 bf

Truss parts: 5 trusses
Jack post 2 x 8 10 – 20’ apx 266 bf
King post 2 x 8 20 – 22’ 586 bf
Double stud 2 x 6 20 – 15’ 300 bf
Web 2 x 8 10 – 14’ 186 bf
Web 2 x 6 10 – 14’ 140 bf

Beams: 4 bays
Box beam 2 x 8 16 – 15’ 319 bf
Triple beam 2 x 8 24 – 15’ 479 bf
Ridge beam 2 x 8 4 – 15’ 80 bf

Rafters 2 x 6 66 – 12’ (2’ oc + 6) 792 bf
2 x 6 66 – 14’ (2’ oc + 6) 924 bf

Roof Purlins 2 x 4 100 – 16’ (2’ oc) 1056 bf

Facia 5/4 x 6 16 – 16’ 169 bf

Siding 1 x 10 1800 + 1440 3240 bf

Flooring 1 x 10 (2200 bf) owner

Total BF 12,249 bf

12,861 (plus 5%) at .85 = $10,932

[JaredWoodcock]

Is it $0.85 per BF sawn?

[Donn Hewes]

Actually I think I can buy the logs at .45 cent and get them sawn for .25 cents, but I still need to figure out how many extra logs to buy. That would be .70 cents.

[Carl Russell]

Hi Donn, I couldn’t resist a little time spent on this…

I came up with;
Tamarack/Larch
5- 22′ logs @ 12″min dia.(135bf/) = 675bf
3- 20′ logs @ 12″min dia (125bf/) = 375
8- 18′ @ 9″ (60bf/) = 480
24-16′ @14″ (135bf/) =3240
12-16′ @12″ ( 95bf/) =1140
48-16′ @9″ ( 50bf/) =2400
2- 14′ @12″ ( 85bf/) = 170
24-14′ @9″ ( 45bf/) =1080
37-12′ @12″ ( 70bf/) =2590
Total =12150

Owners Logs
16-16′ @14″ (135bf/) 10x10x15 =2160
17-16′ @14″ (135bf/) 1x10x16 =2295
Total =4455

I would suggest that you give this list to the logger…… or one like it. It is the way I would see it from the logging end…. number of logs, dia., and length.

I wasn’t sure about the 12.6′ long lumber for your floor joists, but if you need those cut 13′ long for extra trim then that scale may need to change, but the number of logs should stay the same.

I also converted your 15’ers into 16’ers so that they could be interchangeable in the log count…. carpenter can shorten at the site. If the logger is cool with cutting 15’ers, the 12″ logs scale 90bf and the 9″ logs scale basically scale the same. I personally would keep it simple for the logger.

You should ask for the logs to have 6″overlength… which does not add to scale. it is a common convention.

There will no doubt be 8″logs and 16″ logs, so the numbers could change, but using minimum dia gives the logger a basis to work from…… you will no doubt also get all of the other logs that do not meet your order, so the total scale will probably be greater still….. hard to tell without knowing the size of trees to be cut. However there are a lot of 9″, and a lot of 12″ logs, which will probably easily come out of the same tree, so it may be pretty efficient.

Have fun, Carl

[Carl Russell]

Also, I have a hard time believing that Larch is worth more than $300/Mbf ($0.30/bf) on the landing, I’d say more like $250-$275….. plus trucking to get it home should be much less that $450/mbf…..($0.45/bf)

But it is out of my normal market range.

Carl

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