Author Topic: What's your method for calculating how much wood you need for a job?  (Read 5078 times)

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Offline gstuartw

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I'm about to take on my first solo cabinet project. 20 years ago my father in law and I built all the cabinets for the remodel of the house my wife and I were living in. He had plenty of experience and the tools so I was along for the ride, learning the process of building cabinets carcasses from plywood, gluing up panels, raised panel construction etc. That was a great project but unfortunately it was the last thing I did in a wood shop and I didn't learn how to estimate the wood needed.

Now I have my own shop and facing another kitchen remodel. This will involve somewhat typical raised panel cabinets as well as custom panels for a sub zero fridge and an island made to look like a repurposed rustic base cabinet. Still all really just variations of the construction of common cabinets but LOTS of wood.

So what method should I use?  I've seen a range of board foot overage percentages from 10-100% and higher. Some use square feet, some board feet. Some utilize Cutlist or plugins for CAD programs such as Sketchup. How do you calculate your wood needs?

As an aside, I took a cabinet making class at my local Woodcraft and I seem to recall the instructor cautioning against 4/4 wood. He advised that sufficing the wood adequately makes it difficult to end up with 3/4 stock. His advice was going with rough stock thicker than 4/4. I'd never heard that, or maybe I'm imagining I did… no matter, have you ever heard this? Do you start with more than 4/4 in your cabinet projects?

I've included the design for the Sub Zero enclosure to illustrate that part of the project.

« Last Edit: September 09, 2014, 10:19 PM by gstuartw »

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Offline SRSemenza

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Re: What's your method for calculating how much wood you need for a job?
« Reply #1 on: September 09, 2014, 11:32 PM »
   Well, certainly there are lots of methods. I have never used a program but I also rarely do full kitchens. For the sheet goods I usually just figure my rough sizes of pieces and how many of each while making the cut list. Once I have that it is easy to figure how to fit the most pieces into a sheet. I know there are programs to do this , but I find it just as easy to do in my head and on paper.

  For solid wood I mostly use 4/4. Again I make up the cut list so I know how many of what size pieces. Figure how many boards of what ever width will give me the least waste. Jot that down and take it with me to the lumber yard as a reference. Choose the boards I want keeping the list in mind. I generally add my 10 - 20% for waste, mistakes, etc when I make my reference list of board sizes. So that is pretty much built in. EX- if I want two 4" wide rips from a board I just know that I need a board that is 8 1/2" - 9" wide. Then I will grab a couple more boards for good measure.
   When I need thicker boards ( 5/4, 8/4) it is usually only for a couple of pieces and I can just guesstimate and add them to the order.  Of course that all gets converted to board feet when paying.

    I am usually only buying 30 - 50 board feet though. For a bigger job , like a kitchen, I would just figure X amount in square feet of 4/4 (which in 4/4 is automatically brd. ft. also) and add 20%. And probably be buying enough that choosing particular board width wouldn't matter much.

     As far as not starting with 4/4 goes ........  If you are buying from a real hardwood supplier it will most likely be  an actual 13/16" giving you 1/16" to surface and sand. If buying from a home improvement store or big box it is likely to be  an actual 3/4" to start with  so no extra to work with.  I have never had a problem with a 1/16" not being enough unless the board has some real problem to start with. I have also gone a 1/32" under 3/4" on occasion to get the surface I want which is fine as long as you make them all the same thickness , unless there is some part where the 3/4" thickness is critical.

Seth

Offline Jesse Cloud

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Re: What's your method for calculating how much wood you need for a job?
« Reply #2 on: September 10, 2014, 12:10 AM »
What Seth said.

Plus:

Not all 4/4 boards are equal.  Depends on where your yard sources.  One yard I go to, I can count on getting 3/4 milled foursquare 95 percent of the time, so 4/4 is cool.  Another local yard, maybe 1/3 of the board length won't yield 3/4 most of the time.  Another sells S2S from 4/4 that yields something close to 3/4, but if there's any cup or twist that needs correcting you are screwed. 

And, of course, how important this is depends on what you are making, if you need pieces to come together flush, get the best.  If you build in a reveal, you can get away with a little variation.

Also, be sure to look for checks, if the lumber is rough, use a hand plane to take off the rough part far enough to see how long the check goes - a long run can ruin your day.

Offline Tim Raleigh

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Re: What's your method for calculating how much wood you need for a job?
« Reply #3 on: September 10, 2014, 09:53 AM »
How do you calculate your wood needs?

Cutlist. Since you are using Sketchup it or similar plug-in would be the easiest to transition use.
Based on the size of your project I would advise that you use some application. While experienced woodworkers like your father-in-law can estimate by "feel" , the price or gas or shipping, time and materials has changed quite a bit and access to software like Cutllist to optimize your lumber and sheet goods use for a large project such as your kitchen saves time and money.

I'd never heard that, or maybe I'm imagining I did… no matter, have you ever heard this?
No, but it might make sense in some cases.

Do you start with more than 4/4 in your cabinet projects?
[/quote]
When I hand pick my rough lumber I pick to fit the requirements so I can get away with less milling. If I need a wide board and the best I can find is one that is twisted or curved etc. then I will buy a thicker/wider piece so I can mill down to the right thickness.
Otherwise I have my lumber yard mill to my specifications and they always charge me (in linear feet+hr. rate) for rough stock that is 1/4" thicker than my required finished thickness.

I've included the design for the Sub Zero enclosure to illustrate that part of the project.

Interesting, the width of the rails and stiles give it a "Spanish Colonial" feel.
Tim

Offline SRSemenza

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Re: What's your method for calculating how much wood you need for a job?
« Reply #4 on: September 10, 2014, 10:05 AM »
  Couple additions to my post above .....

       The 13/16th that I buy is not rough. It has been planed. If it was rough it would be more like an actual 4/4.

       And because it is mostly smaller jobs and I can really hand pick the boards , I am avoiding any boards that have more than a bit of cupping, checking, side bend, etc.  If  I have to take cupped boards I make sure to figure using them for narrow pieces. And I make sure to get flat (nearly) ones for wide pieces.


  So for those jobs it is easy to be choosy and minimize extra. But for a bigger job it is more like buy a stack and a good amount of extra.


Seth

Offline Loren Woirhaye

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Re: What's your method for calculating how much wood you need for a job?
« Reply #5 on: September 10, 2014, 11:38 AM »
Those long stiles will be tricky to mill straight.  I suggest you start with the straightest 5/4 stock you can get for those.   If you want to go to 1" thick frames you may want to go with 6/4 for the stiles, depending on how skillful you are with milling. 

All those little panels can be made from short offcuts.  It's the long, straight clear parts you need to worry about getting right.

A lot depends on the type of wood too.  Some woods, like oak, are just very reliable and you can buy it skil planed and look at it at the lumberyard and it sometimes comes off the sawmill quite straight.   The skip planed 4/4 oak I get is about 15/16" I think.

You can go down to the yard with a lumber crayon and a 78" level and assess and mark straight sections of the boards that interest you.  Tally up those crucial parts and assess from there.
« Last Edit: September 10, 2014, 11:42 AM by Loren Woirhaye »

Offline Tim Raleigh

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Re: What's your method for calculating how much wood you need for a job?
« Reply #6 on: September 10, 2014, 01:19 PM »
Those long stiles will be tricky to mill straight.  I suggest you start with the straightest 5/4 stock you can get for those.   If you want to go to 1" thick frames you may want to go with 6/4 for the stiles, depending on how skillful you are with milling. 

All those little panels can be made from short offcuts.  It's the long, straight clear parts you need to worry about getting right.

Hmmm, I am not sure why you say that milling those long stiles will be tricky...?
Maybe I am missing something...
In order of magnitude, milling these stiles would be trivial compared to the complexity of the (kitchen) project.
Tim

Offline SRSemenza

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Re: What's your method for calculating how much wood you need for a job?
« Reply #7 on: September 10, 2014, 03:48 PM »
I am curious as to why starting with thicker wood will make it easier to mill the stiles straight? Flattening? I generally find  that 3/4" thick material  for a narrow piece like a stile has enough give to be flattened to the carcass when attaching it if need be. Assuming it has a uniform thickness.


Seth
« Last Edit: September 10, 2014, 04:46 PM by SRSemenza »

Offline Hookie

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Re: What's your method for calculating how much wood you need for a job?
« Reply #8 on: November 11, 2014, 05:22 AM »
I draw out the job, to scale, on 5mm squared paper.  Just the main elevations you would find on a drawing proper. All parts named and dimensioned.

Then I just count the pieces, and do the necessary maths. I also make notes of any variances of construction, or materials along the way.

If I am cutting pieces from sheet goods, I also draw those to scale, and divide them up on paper, to check the cuts. This gives me something to take to the yard, as my local supplier has a free cutting service, for all purchases. 

I usually buy 10% extra for waste.

I do find that 1 inch rough-sawn often mills to a lot less than the normal 7/8". Usually due to slight bowing or wind that sometimes occurs. So I have taken to buying stock a 1/4" thicker!

HTH

John
« Last Edit: November 11, 2014, 05:27 AM by Hookie »
It started with a : TS 55 REBQ-Plus-FS
Then parallel guides.... Extra tracks. Then a Domino 500! Now a Midi extractor. Next an MFT, Domino XL,  Dominos and cutters. Router, OF 1400 added to the armoury... Just bought my 'Domiplate'.. The LR 32 jig and track. And finally, A TS 75 Track saw, sans track. My shop is turning very green and black.
Regards, Hook.