How much material to buy for a project?

[Chris Fournier]

Dave gave a very complete account of how wood is actually used when you're making something.

Here's a few more comments

1) if your planer has snipe, you'll lose at a minimum 5% of your material, realistically 10 to 15% as you'll be cutting and planing multiple components per board

2) Jointing and planing will take somewhere around 25% of the material (for example you'll plane 4/4 stock to 3/4. (note that you can ignore this if you're making furniture, you can't ignore it if you're selling the product by volume).

3) selecting for grain and culling defects can take 10 to 25% of the material.

In my projects I normally purchase 25 to 50% more material than I use in the project.......................Regards, Rod.

If your planer has snipe why wouldn't you tune it to eliminate the snipe? I'd never buy more material because I hadn't fettled my equipment as that would be bad practice. My point of view of course.

[Rod Sheridan]

If your planer has snipe why wouldn't you tune it to eliminate the snipe? I'd never buy more material because I hadn't fettled my equipment as that would be bad practice. My point of view of course.

I agree, however if you have snipe you have to account for it.........Rod.

[Rob Luter]

I guess it depends if you want to match grain, etc. When I toured the Stickley factory a couple years ago, the guy showing us around said on a good day they'd net out at about 50%.

[Osvaldo Cristo]

As previously stated, it depends.

For man made sheets, usually is close to zero the surplus I purchase. Quite close to zero for very high quality for prepared and squared lumber when I choose each piece carefully.

For rough lumber it can be 10% up to 50% depending of the required and available sizes and the wood quality.

[Ron Citerone]

There is no single answer. It depends.

It depends on how carefully you match your board sizes to your cutlist. Just saying xx bf doesn't say much if you buy a 7" board and rip 5" wide pieces out it with nothing to do with the offcut. Same thing if you need 6' pieces and all the boards are 8' long.

It depends on how many defects there are in the material (currently visible and those you discover when breaking the material down) and how carefully you are planning your cuts around them.

It depends on whether you cut your pieces out oversize and let them stabilize before milling them to final dimension.

It depends on how you figure your needs. If you need a piece that's 1.5" by 6', is that 0.75 bf or is it 1 bf?

It depends on how worried you are about grain placement and orientation -- if you're picking out all rift sawn material for stiles and rails so you don't have grain arches that don't mesh aesthetically, you might need more because you're discarding some flatsawn portions of boards. Are you cutting around sapwood?

It depends on what you're making. What it takes to make a table top is pretty easy to project when you have a pile of boards to choose from. For more complex projects, it may be harder to connect.

It depends on whether you're buying random width material or material that's S4S so you know exactly what you're getting.

For that matter, it depends on how your supplier scales lumber. Some scale in a broad way ("oh, you've got three layers that average 3' by 7' so lets say 63 bf"; often these types allow a fair amount of overage) and some measure every piece to the quarter inch, and then round up. Some suppliers won't even let you pick your own boards, though I wouldn't buy from them unless you are buying large quantities on spec, and the price you're paying reflects the additional waste you are likely to experience from material that you probably wouldn't have otherwise taken home.

When I pick lumber for a project, I start by finding the boards that will be the "show" pieces -- the table top, the door panels, the crest rail, the drawer fronts, whatever are going to be the pieces people "see" when they look at the finished piece. Once I have those, I look at whether the offcuts from those boards will make anything useful, then figure the minor components from there. I don't go in to buy X bf of lumber. I'm not saying doing it by bf is wrong, just not how I go about it.

I'm not making light of your question. I'm just saying, "it depends". . .because it does.

Best,

Dave

I really don't like the percentage extra idea. Dave's post above from above is well written good advice.