workshop table supports - can it be done without a front beam?

[Cory filder]

Hello,
I'm trying to maximize the amount of vertical space Under a shop table I will be Building in the shop. every inch counts. there are a few reasons why this needs to be done. This tabletop is will built for functionality, not aesthetics.

the plan is to get a hold of a 1 1/2" butcher block top 2'x4', or a glued double 3/4 Baltic birch plywood ( which I have lying around, and more likely to use). I do have extra space on the sides and back, so I will be able to build a beam there. I will not have extra space in the front the table.

I am trying to build it without beam in the front, but only if possible. however with the 1 1/2 thickness of the Baltic birch plywood, Would I have issue sagging? like any shop I be a little rough with the top, but not too much weight. my hope was that the extra thickness of a 4 foot span and hardwood plywood would allow for no sagging in the front. can this be done? or must I have a beam no matter what?

thanks

[jack duren]

Remember…. Gravity always wins..

[Kris Cook]

I would imagine it depends on what you plan to use the table for to some extent. How about building a torsion box?

[Paul F Franklin]

Will it be against a wall? You could use a floating countertop support bracket (essentially a giant L bracket made of steel). If not against a wall, you could use a length of 3/4 square steel tube at the front edge, under the first layer of plywood.

[Bill Dufour]

Attach a piece of 1.5" angle iron across the front with countersunk screws.
Bill D.

[Robert M Richardson]

Since you know the final size of the bench run a test. Use plywood, cut two pieces, place them across a couple of saw horses. Then get say 6 F clamps and clamp the two pieces together, 3 clamps to each long side, evenly spaced to prevent the two sheets from slipping relative to each other so they act in concert. Load it up with whatever you have available to simulate the working load and measure the sag. If there is any try spacing the two sheets of plywood apart with say 1/2" strips. Now you have something like a wooden I beam. Reclamp and test again. The final top will be glued up and or screwed together which will prevent slippage between the two sheets the clamps will preform that function but allow you to regroup if sag appears.
Robert

[Tom Bender]

It will suffice for most purposes and I doubt it will fail but for any kind of pounding it will steal some of the impact.