Help Design Sturdy Counter

[spotco2]

I am building out a new service van and need some help coming up with a design for a workbench countertop. It will be covering the blue parts bins in the pic. The total size will be 18" wide and 96" long. The section over the blue bins is about 56"x14" and has a solid back.

The issue I am running into is the counter top needs to support about 150 lbs without sagging or bouncing. I was toying with the idea of making a countertop base out of 4 strips of 13/16" Unistrut with 3/4" birch on top of it but not sure if that would be strong enough to keep it from bouncing. The front 4" of the counter top will be unsupported for the length of the top.

Any ideas or suggestions would be appreciated. I would prefer to stay with a wooden top than a bent steel (not easy to source here).

 

[matt_i]

I'm not totally sure I understand (is the top an extension of the thinner piece at left but fly over the blue bins?) but a couple generalities....your columns down to solid material will be the most rigid parts. To help with stiffness you can use something like 1x2 nosing on the 3/4 plywood, glue it up with wood glue = OK or construction adhesive = better. Along those lines you can also glue and screw wooden "ribs" to the underside of the plywood surface, your choice as to how many. The ribs could potentially be made from something metal like thin angle iron (bedframe or smaller, even aluminum) that would take up less space than the wood ribs. Should be able to source that at a box store.

 

[gahrajmahal]

Draw your design and send it to unisrut . They should be able to tell you the deflection of your shelf with a 150 lb load.

 

[spotco2]

I'm not totally sure I understand (is the top an extension of the thinner piece at left but fly over the blue bins?) but a couple generalities....your columns down to solid material will be the most rigid parts. To help with stiffness you can use something like 1x2 nosing on the 3/4 plywood, glue it up with wood glue = OK or construction adhesive = better. Along those lines you can also glue and screw wooden "ribs" to the underside of the plywood surface, your choice as to how many. The ribs could potentially be made from something metal like thin angle iron (bedframe or smaller, even aluminum) that would take up less space than the wood ribs. Should be able to source that at a box store.

Sorry that piece of plywood was just laying there. Maybe these pics will help a little more. The right end would be on top of the 3/4 material that is vertical. The other end will eventually stop at the rear doors of the van. The front edge of the shelf where the blue bins are and the square box is 14" and the counter top need to be 17"-18". In the last pic is a piece of plywood just laid in place where the countertop needs to be.

 

[homebuilt burner]

What are your thoughts on getting a piece of butcher block? 96" long is pretty easy to find, that would support the 150 lbs load. Otherwise, a piece of 12 ga with both inside and outside edges bent 90 and 90 again.

 

[nmk_61802]

torsion box?

 

[spotco2]

torsion box?

Had not considered that. Looks promising. Thanks.

 

[spotco2]

torsion box?

I have equipment that will need to be bolted to the bench that weighs 50-60 lbs each. This might present an issue with the torsion box and the box might be to thick to allow for a comfortable work height. I was hoping for something 1-1/2" or less. I am not sure exactly where on the counter the equipment will be bolted yet.

 

[mikegt4]

I hope that you fasten down or restrain all those bins and drawers, they will all be on the other side of the van after the first corner. Don't ask me how I know that,,, or how many times I know that.

 

[Lynden]

I would research a couple of options....

1. A plank top made out of douglas fir or southern yellow pine. Both have good stiffness ratings. Go to a good lumber yard and order two 2x10x8' boards (No. 1 or better, kiln dried, vertical grain). Joint one edge of both boards and glue and dowel them together. Attach a length of 1/8" steel angle along the front edge.

2. A plywood top made out of a sheet of 3/4" marine plywood. Cut the plywood to size and glue the two pieces together. Attach a length of 1/8" steel angle along the front edge.

With both options add 3/4" oak edge banding on the three edges without the steel angle. Let the angle and banding stick up above the table surface 1/4" and add a piece of 1/4" tempered hardboard to the surface. Attach the hardboard with brad nails around the perimeter so that it can be removed and replaced easily.

 

[spotco2]

torsion box?

I hope that you fasten down or restrain all those bins and drawers, they will all be on the other side of the van after the first corner. Don't ask me how I know that,,, or how many times I know that.

They are bolted to the floor with multiple 5/16 bolts and plusnuts. They are also bolted to the wall at the top with 1/4" strap toggles. The cabinets in the pic are also anchored to another shelf going across the partition. Ain't my first rodeo.

 

[bugnut]

My suggestion is a takeoff of the torsion box. A couple pieces of plywood with 1x's and black iron pipe as stiffeners. Would hit your thickness and easily support the 150lbs. All materials locally sourced or I might use the prefab perforated angle available at HD, lowes etc

 

[spotco2]

Just a follow up. I spoke with a commercial cabinet shop that is a customer of mine and they are gluing up 2 pieces of 3/4 hardwood plywood with a piece if 1/2" in the center to try. They seem to think it will not have any deflection over the span I am concerned with and if there is, then we will try something else. They are supposed to have it ready early this week.

 

[spotco2]

Sadly had to end up bracing the center to keep it from sagging and bouncing. It's done. Maybe try something else next time.