Your workbench is the wrong height, and your back knows it

Quick answer: For general work, the top of your bench should sit at your wrist crease when you stand with your arms hanging at your sides. Go a few inches lower for planing and sawing. Go higher for fine, close work. If you can only pick one height, pick the wrist crease and build from there.

The Saturday that ends at 9 p.m. with a sore back

You start a project at nine in the morning. By noon your lower back has an opinion. By mid-afternoon your shoulders are up around your ears and your cuts are getting worse, so you blame your skill and quit early.

Often it's not your skill. It's the bench.

Many ready-made benches come in around 36 inches. That works if you're about six feet tall and mostly assembling things. For everybody else it's a guess. A bench that's too high makes you shrug your shoulders to work, and your arms tire fast. A bench that's too low makes you hunch, and your back pays for it. Either way you stop leaning your weight into the work and start fighting it.

Find your number in two minutes

Stand on the shop floor in your work shoes. Let your arms hang loose. Have someone measure from the floor to the crease of your wrist, where the hand meets the forearm. Then measure to your knuckles and to your elbow while you're at it.

Write all three on a piece of masking tape and stick it on the wall. You'll use them.

• Wrist crease: the all-purpose height. Good for layout, assembly, sanding, drilling and most of what you'll do.
• Knuckles or a little lower: heavy hand work. Planing, sawing, chopping, anything where you push your body weight through the tool.
• Near the elbow or higher: detail work. Carving, small repairs, soldering, anything where you need your eyes close to the job.

A man who's five-ten will usually land somewhere in the mid-30s for general work. A man who's six-three will be higher, and a shorter man or most women will be lower. Don't trust the chart, trust the tape. Your arms and legs don't match anybody's average.

Test it before you cut a single leg

Don't build to your measurement and hope. Fake it first.

Set a sheet of plywood or a solid door across two sawhorses, or stack your current bench on blocks. Adjust the height with scrap lumber under the supports. Then do real work on it for an afternoon. Plane a board edge. Drive screws. Saw a few pieces to length. Mark layout lines and see if you can read your pencil without stooping.

Pay attention to where you feel it. Tension between your shoulder blades says the bench is too high. An ache across the low back says too low. Wrists bent upward while you work mean the same thing. If it feels good in the first twenty minutes and bad in the second hour, you need to go lower than you think.

If you've got a back problem that doesn't go away when the bench is right, that's a question for your doctor, not your lumber pile.

Raising or lowering what you've already got

Raising is the easy direction. Bolt or lag a pair of 2x4 blocks under each leg, or build a plywood platform to set the whole bench on. You can also add a second top layer. Two sheets of three-quarter plywood glued and screwed together add an inch and a half, and they make a flatter, tougher surface anyway.

Lowering means cutting legs. This is where people get hurt, in their wallets and sometimes on the saw.

• Measure how much you need to remove. Then take off a little less than that.
• Cut every leg to the same length by marking from a single reference, not by measuring each one separately.
• Cut, set the bench back down, and work on it. You can always take another quarter inch. You can't put it back.
• If the bench has stretchers, check that they still clear your feet and your tools after the change.

If the bench is heavy and you aren't sure, build a lower platform to stand on beside it instead. There's no shame in a pair of thick rubber mats. They help your legs on a concrete floor anyway.

When one height can't do everything

Here's the honest trade-off. A single bench can't be perfect for sawing, planing, assembly and small repair. Everybody who works wood a long time ends up compromising.

You have a few options, and none costs much.

Build a sawbench. A low, sturdy bench just for cutting and rough planing gets your body over the work. It's a good first shop project, and I've covered how to build a sawbench first, then build everything else on it.

Raise the work, not the bench. For close detail, clamp a small board or a bench-top riser on top. Two inches of lift costs you an hour and some scrap, and you can take it off when you're done.

Set your vise to your hands. A vise mounted so the jaws sit near your elbow height holds small work where you can see it. The same vise at knee height makes every chiseling job a stoop.

If your shop is a tight garage, think about all of this before you commit space. A garage workshop you'll actually use on a Tuesday night starts with a bench that fits the man and the room, not the other way around.

The small things that matter as much as height

Height is the biggest fix, but it isn't the only one.

Light matters. A bench in a dim corner makes you lean toward the work, and that puts your back right back where it was. Put a bright light over your hands, not behind your head where your shadow falls on the cut.

Reach matters. If you keep stretching for a tool, put it within a step. A bench with no clutter lets you stand square to the work instead of twisting.

Footing matters. Cold concrete and hard shoes wear you down faster than any low bench. Stand on a mat. Wear boots with a decent sole.

And working tired matters most. Plenty of the injuries I've seen in other men's shops, and a few of my own, started with a long day at a bad bench and one more cut that should have waited. I wrote about that in everything I do differently after the shop hurt me. Fix the bench and you'll stop at the right time without having to force yourself.

Do it this weekend

Get the tape. Measure your wrist, knuckles and elbow. Stick the numbers on the wall. Then spend one afternoon at your bench with scrap under the legs, and adjust until your shoulders drop and your back stays quiet.

You'll notice the difference in the first cut. Lines come out straighter, chisels stay under control, and you finish a day's work still wanting to do more.

A bench is the one tool in the shop you use on every single job. It ought to fit you.