Woodworking 101 — simple table braces

Factual Questions
1

The electrical work is done and I’ve been organizing and arranging things for a workshop. I have a good spot for my drill press and miter saw, but need to build in a table. I’ve made the top and tested it out space-wise (I’ve had it clamped it to a pair of sawhorses), and now it’s time to liberate the ‘horses and secure it to the wall.
First off, I’m thinking that by angling braces from the bottom of the table to the wall (rather than put regular legs from table to floor), I’ll open up the space a bit more. Is there any reality behind that perception? It seems rolling a shopvac or sliding boxes in and out from under the table will be easier if there’s just angled brackets rather than legs to contend with. If this description isn’t really helpful, here’s what I’m planning on (Imgur link).

Assuming this is even faintly correct, then what? I’ve searched on several keywords (table wall bracket …), but haven’t found the right implementation.

How do I determine where the braces should go, how many, and their thickness? The table will have a drill press and a miter saw, so it’ll have a hundred or so pounds on it at the very least (notice too that it’s not a straightforward rectangle). I have other workbenches where my vices/anvils are, so I don’t need it to take excessive weight, but I’d still rather overestimate its weight-bearing needs.

So let’s say I have my 2x3s picked out (I have extra 2x3s, so I hope they’ll be sufficient), now what? For each placement, how do I figure out the length the braces? I remember my Pythagorean formula, but only as it applies to one-dimensional lines. I also remember Pythagorean triples, so are there certain places to hit on the table where cutting to length will be more straightforward?

About those braces—cut them at 45-degrees to fit flush against the table bottom and stud face? (Good thing I have a miter saw).

Then about attaching them. Do I just guess at screw size/number or are there charts to help figure this out? Do I drill through the braces to make a shank hole or does this need more thought/technique? Since the table will be subject to vibration over time, do I need to do anything about the screws?

And lastly (as far as I know), how to attach the table to the wall? Do I put the two or three angled braces on the wall first, then secure the table to them (again, how to figure that out length/type/etc.), then secure the rear of the table to the wall?

This may seem trivial and intuitive, and I’ve figured out similar constructions before, but perhaps you could help or point to a site with step-by-step instructions that will cut down on the mistakes and trial and error a bit?

Thanks,

Rhythm

2

2X3 is kind of light for that kind of thing. If you have a lot of heavy stuff on there, or you are pounding with a hammer you’ll end up with a shaky table that will eventually fail. If you’re going to do it that way you need to attach vertical 2x4s or heavier lumber to the wall to attach to. If you look into workbenches you’ll find that only very heavy vertical wood supports with very tight bracing will do. Metal legs are preferable. Metal workbench legs used to be readily available, but I don’t find them much anymore. I’d suggest before doing anything see what is available from Grainger, McMaster-Carr, or MSC.

ETA: And to attach to the table bottom add some wood under the top to attach the braces to. Attaching tops to workbench legs or braces is a whole science in itself. Of course if it’s all light duty, just do anything.

3

I agree that 2x3s are probably not sufficient for this task.

I would use 2x6s for the legs, with one every leg every four feet. That should provide plenty of stability for a bench with heavy tools on top.

Rather than trying to calculate the exact length of the pieces, here’s an easier way. Miter one end of your leg at a 45-degree angle and tack it to the wall temporarily. Then use a level horizontally to represent the underside of your table structure. Use the level to draw a line on your diagonal leg, then cut. Then, use that leg as a template to make more.

4

Personally, for strength and simplicity, I would go for vertical 4 x 3 legs and a 2 x 4 along the leading edge of the bench. You maw want to reinforce the places where equipment will be attached as well.

5

I should have noted that by attaching vertical lumber to the wall you can attach your braces to the sides of those pieces. And put a horizontal piece on the wall for the back of the tabletop to rest on.

6

I have three 60x36 workbenches that will take the heavier work. My primary bench has the vice and anvil (though the anvil is portable), the spill-over bench is where I’ll keep in-progress and waiting things (kind of a control-the-mess top so my primary doesn’t get over-cluttered), and the third will likely have a couple machines (grinder, sander, etc.). I do want it it support a heavier load than I’m imagining, but not sure I’ll be pounding anything on it per se.

Nonetheless, how do I go about figuring out approximate load capacities? I know the top is 3/4" oak plywood, the angles I’m assuming for now are 45 degrees–are there calculators that can tell me what loads are likely supportable? (Oh, I’ve been assuming I’ll have heavy duty metal brackets where the top meets the wall.)

7

You can reinforce the top, with the back piece I mentioned above, and more lumber under the table. I have no idea how to calcuate the loads, I always take what I figure is enough and multiple it several times until I exceed the heaviest material available. More is more when it comes to work benches.

But you seem to be adding a light duty bench, more like a desk so I have the feeling you’ll work it out. I prefer benches on wheels now. My best bench isn’t big, it’s got the big machinist vice and the anvil on it, and I have a metal forming tool I never use but it’s rock solid attached to that. It’s an old disk drive cabinet from the seventies, heavy steel with 2" oak planks on the top. I threw out the original casters and added the heaviest ones I could find.

Another good choice for a heavy movable work table is to get an old Shopsmith. They can be found for around $100, especially if the power head isn’t working. Those things are strong as stone and they’ll have a tilt table with vertical adjustment. I used my old one that way for a long time with a plywood top on top of the small worktable it comes with. If it works at all it’s a fantastic rotary power unit. Don’t pay much for old Shopsmiths unless they are in excellent condition.

8

I agree with a ledger to support the table top at the wall (use lag screws), but I’d go with vertical legs rather than knee braces. No load calcs, and all the forces are directed down to your floor instead of to wall members. A couple or three 4x4s with a stretcher across the top will handle anything you put on the table, and still give you space underneath for storage. I’m sure you can buy clips at any DIY store to put it all together.

9

Are you planning to attach it to a stud wall or a concrete wall? If the latter, no worries. If the former, what’s on the other side of the wall? How well supported is the wall?

10

I think you are all over thinking this.

Checkout this Woodsmith Shop video and it will give you plenty of ideas to start with.

With the amount of weight that you want to put on it, I would suggest that you attach the angled pieces permanently instead of the way they do it in the video.

The video suggests putting an edge around the plywood top to keep pencils and stuff from rolling off. You won’t need that, but (I assume you are using some 3/4" plywood for the top) you will need some kind of support screwed to the bottom of the table top to prevent sagging.

I think 2x3’s should be plenty strong enough for what you want to do.

I would suggest using the 2x3’s to make an apron under the table top. Just screw the 2x3’s to the bottom of the table top around the entire perimeter flush with the edge of the table top. That will help prevent sagging and also give you a way to attach it to the wall (go through the apron into the wall). Your wall will dictate what kind of fasteners to use. Cinder block, concrete, bare studs, drywall between studs, etc… all require different fasteners. Any hardware store or big box home center should have a display telling you which fastener to use for your needs.

With the apron, you should be able to attach the angled pieces using either a lag bolt or carriage bolt (1/4" should do it). Just have the angled pieces under the top, behind the apron, then drill a hole through both and use the bolt to connect them.

11

I’ve learned through sad experience not to shortchange oneself when designing something. A lightweight structure will do fine for present needs, but it can’t hurt to beef it up a bit juuuuusssst in case a future tool purchase requires something sturdier. :smiley:

12

Kinda like explosives, carefully calculate exactly what you need, then double it to make sure you don’t have to do it over. :smiley:

13

If your top is properly reinforced, don’t take the 45 degree braces all the way to the front of the table. That weakens the structure. 1/2 way to 2/3 at the most. The shorter braces will be stronger. The smaller the triangle the stronger it will be based on the same sized materials.

14

Well, sure to some degree. But think of an average kitchen table. It would easily hold both a drill press and miter saw and could still easily handle someone banging on it.

There’s no need to spend money for new, big, beefy lumber when what he already has on hand will more than meet his current needs. If, in the future, he needs something bigger and stronger, go spend the money then - if that time ever comes. It would be different if he didn’t have any wood to start with.

15

I will add my vote to over building this particular item. Work benches should be heavy. Skip the brackets and give it legs to the ground with a hefty skirt around the top.

The old garage standby of legs, skirt and low shelf built out of 2x4’s or 2x6’s is simple to build and very sturdy. If you want something more precise mill the members out of heavy sheet stock and build box legs. I rebuilt our shop bench last year and built it out of 24 & 30" cabinets for storage and a 1 1/2" thick melamine top. I worried that configuration might be too light, but we also have a really heavy run out table for the saw that I use for heavy work.

When you are clamping together some complex construction or working some awkward piece clamped to the bench you will appreciate a bench that is sturdy and doesn’t move and the character of the space under the bench will be of limited relevance.

Edit - sorry I missed post # 6 that you already have some heavy benches. I am still with Chefguy however, give it legs.

16

I built my bench using sistered 2x4s vertically to the floor. Much easier to build, no fancy geometry calculations, and it’s sturdy enough for me to climb up and do a jig if I ever feel the urge (hasn’t happened yet, but you never know). I’ve never once felt the vertical supports were in the way.
mmm

17

The angled braces to the wall will be strong enough to hold your bench, but if you ever need to bang away on something on that bench, your wall will shake bad enough to break any mounted light bulbs in or outside the shed. Can you guess how I know that? :slight_smile:

I have since used 4x4’s as legs to support the front of my shed bench. They don’t steal that much room and my exterior light continues to work.