9.5' long workbench span question

[stev0258]

Hey Everyone

Looking for some feedback. I'm building a workbench to go inside a bump-out in my garage. See attached pictures but I will screw the back and sides into the walls. Bench dimension is 9.5' long, 28" deep, 37" high. Top surface is two 3/4' plywood with MDF over that.

My question is whether two 2x4's screwed together will provide enough support on the front edge across the 9.5' span. Do you think it will be bouncy or sag/flex?

I prefer 2x4's as it gives more space underneath to store things.

Any other points of feedback are appreciated too

Thanks

 

[kd3pc]

I have attached a 2x4 to the back wall, set the bench on that...provides continuous support and you can attach the 2x4 on every stud. That and the double 2x4 front should be quite stable. I would be prepared to place another leg on the front, though, given the length.

But then I tend to overbuild things.

 

[Falcon67]

I think you're going to need at least one leg in the center to support that span. If you plan on shelving under the bench, that can be set back from the front 12" or so. I have shelving that spans 12' with a 2x4 frame attached to walls on 3 sides but that's static loading. Bench work is more dynamic.

Supports under mine

 

[rsanter]

Of you can go all out and make a butcher block type top of all 2x4s sitting on cleats at the ends

If you go with the 2. 2x4s across the front you can always add a piece of steel bar stock to the back of them or between then to make it much more rigid. A piece of 3/8 by 3" hot roll isint going to flex much

Bob

Bob

 

[A**holes Garage]

build it out of steel or Unistrut, if you have the capability

 

[8man]

Depending on what you want to use it for, you may want to go with a leg mid point or go to a double 2 x 6 to take the bounce out. Check the Southern Yellow Pine span chart to get the load and the size you need.

 

[elronin]

If you can get an old 2" butcher block you would not need a 9' 2x4 span. To bad I didn't find GJ until a couple of years ago If not I would have given it to one of you guys. I had 2 large old high school wood shop butcher blocks at home years ago. I kept a 7 foot section, and tossed out a 10 foot section that was a little rotted at the very end from having been leaning against the wall and in 1 inch of water for years. It only was damaged for the first 6 inches. I ended up putting it outside and someone came buy and picked it up. They both had angle Iron that ran all the way across. It was a great score that a school near me was throwing out.

 

[stev0258]

Thanks everyone!

I like the idea of adding angle iron or a unistrut to the back of the stacked 2x4's, I had'nt thought of that. I will look to see what the store has.

Otherwise, maybe even just a 2x2 in the middle might be enough to take the flex/bounce out.

On a related note - when constructing two 3/4" plywood together for the top surface, do people use construction adhesive or just screw them together?

Thanks

 

[kd3pc]

I use west systems epoxy...but construction goo will work

 

[sz0k30]

Glue AND screw.

 

[WQ59B]

I have a double-ply top, 12-ft bench. Frame is 2x6, has 6 2x6 legs. I think it only has 5 or 6 2x4 'joists' under the top. Is lagged into the 2 6x6 posts of the building. Zero bounce on that set-up. Top is screwed, no glue. Holding up pretty well, going on 21 years.