Sawmilling: Thickness guidelines
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Differents customers want boards sawn to different thicknesses--what are the standards? August 12, 2001
Question
I have been sawing boards for myself at 1 1/8" thick, figuring that after drying, I will be able to plane them to 3/4" easily. But recently I have been sawing for customers. My first customer wanted the lumber for a small barn, and he quickly informed me that I was wasting his wood and should adjust down 1" on each cut, which would give him a board 15/16". Thinking that I had a handle on it now, my second customer accused me of sawing too thin so I could run up the board footage count. I now ask first. What is the correct measurement to saw 1" boards to? And then what about 2" and 4"?
Forum Responses
I think the correct thickness is whatever your customer wants. Thickness is one of the main subjects I discuss with each custom job. I just give them a rundown on what I can do and let them decide. Sometimes it helps to have a sample of each thickness so they can get a visual idea of what you are talking about. I have sawed thicknesses from 7/16 on up. I'd just keep asking. For my factory customers, I saw 4/4 lumber 1 1/8", 5/4 lumber 1 3/8", 6/4 lumber 1 5/8", 8/4 lumber 2 1/8".
I agree with the previous response. It depends on what they want. I ask them what they intend the wood for and give them a few suggestions as to what I think, as far as shrinkage and so forth, and let them decide. Most of the time, they have me saw it pretty much 1/8" over, since the board off the mill is usually very smooth to begin with, and most of them are used to working with nominal size lumber. Of course there are exceptions. As far as framing lumber, I saw it 1 5/8 thick and 3 5/8, 6 5/8, 7 1/2, 9 1/2, 11 1/2 on the widths. That seems to put it just right after drying.
Is it green or dry, cabinet wood or framing lumber? Shrinkage? Finished product? All questions to be asked of the end user.
There are legal minimum thicknesses if you are selling the wood on the open market. For example, an air-dried 2x10x8' must be 1.50" x 9.25" x 8.0' at the time of planing and grading. If you are selling hardwood lumber, a 4/4 piece must be 1.00 minimum thickness in the clear areas used for determining the grade (which applies to green or air-dried) and further, the clear areas must surface to the minimum standard thickness. This in turn means that for most mills the average green thickness is at least 1-1/16" and sometimes 1-1/8" or even a little thicker.
But, as stated, the customer is the key. However, for a customer that wants it thicker, you will lose yield--about 2% for each 1/32" increase in thickness.
Gene Wengert, forum technical advisor
When sawing directly for a customer, whether on site or with my logs, I always discuss thickness with the customer. Being a 2x6 could be 1.5 x5.5 or 8 qtr by 6in and so on.
Even in hardwoods, check if they want a 1 inch board or a 1 1/8 inch board. The hardwood 4/4 and softwood 4/4 are different.
I let my customers decide how thick they want their lumber. Keep one thing in mind when sawing lumber less than 1" thick--your time sawing. I make sure that the customer understands that for any lumber I saw < 1" thick, the BF is figured at 1" thick. Of course this only matters if you charge by the BF.
