Torsion boxes

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Forum topic by Betsy posted 02-14-2009 05:37 AM 2397 views 0 times favorited 10 replies Add to Favorites Watch
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3333 posts in 3315 days

02-14-2009 05:37 AM

Topic tags/keywords: torsion box

Can you use thick cardboard as the interior of a torsion box? Seems to me I’ve seen an article somewhere that said some large tables and doors have cardboard at the core. Wasn’t sure though. So can you use cardboard? Seems like it would be a good, cheap, readily available material to use.

-- "Our past judges our present." JFK - 1962; American Heritage Magazine

10 replies so far

View doyoulikegumwood's profile


384 posts in 3412 days

#1 posted 02-14-2009 05:43 AM

yes you can it work great i wouldnt use it for a work bench tho

-- I buy tools so i can make more money,so ican buy more tools so I can work more, to make more money, so I can buy more tool, so I can work more

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John Ormsby

1283 posts in 3156 days

#2 posted 02-14-2009 06:12 AM

The better way to go would to make it out of melamine and particle board. The material is inexpensive and will give you very good results. The box should be at least 6” thick. I just used full sheets for the top and bottom. You will also want to do the grid at about 6” on center so as to have a very strong box that will last forever.
The most important part is that it be built on a PERFECTLY flat surface. I used my dead on flat workbench to make mine. It will be useless if not built flat. This means not twisted and no dips or rises on the top surface.

They are the surface in which one will use to assemble and use jigs for precision cutting, routing, etc.

Good Luck, John

-- Oldworld, Fair Oaks, Ca

View robdew's profile


84 posts in 3134 days

#3 posted 02-14-2009 04:26 PM

if you want it lighter weight, drill out the centers of your interior pieces (obviously no so much they flex tho).

View Bureaucrat's profile


18337 posts in 3071 days

#4 posted 02-14-2009 05:07 PM

The technique you suggest is commonly used to make hollow core doors.

-- Gary D. Stoughton, WI

View Don Butler's profile

Don Butler

1081 posts in 2815 days

#5 posted 02-14-2009 09:55 PM

There is a paperboard product specifically intended for torsion box use. The manufacturer calls it Tricel and I believe you can get small quantities (not full 48”x96”). The holes in the honeycomb interior are crosscut so you get a true torsion box effect.


-- No trees were damaged in posting this message, but thousands of electrons were seriously inconvenienced.

View Betsy's profile


3333 posts in 3315 days

#6 posted 02-14-2009 11:54 PM

Thanks for the tips guys. Don – I’ve not heard of Tricel – I’ll look into it.

I’m going to make some torsion box shelving units for my knick knack and pictures. I seen some shelves that look like “L” on their sides – those look good and would fit the spot I have.

thanks again.

-- "Our past judges our present." JFK - 1962; American Heritage Magazine

View Don Butler's profile

Don Butler

1081 posts in 2815 days

#7 posted 03-06-2009 04:29 PM

I thought about this thread and eventually somthing occurred to me, a material that would provide the lightness and stability and would be extremely easy to work. I have some and will build a torsion box with it as soon as I can get my workshop back into working status.

Extruded polystyrene, or as we know it, commonly, Styrofoam!

The only thing one must be careful of is that it shouldn’t come into contact with volatile solvents. It can quickly become a liquid!

Film at eleven!


-- No trees were damaged in posting this message, but thousands of electrons were seriously inconvenienced.

View davcefai's profile


37 posts in 2816 days

#8 posted 03-08-2009 02:50 PM

The whole point of a torsion box construction is stiffness so that it will stay dead flat when loaded.

So building the structure with other than a material which will not flex is a pointless exercise.

Doors are filled with cardboard to impart some rigidity to the plywood panels and to deaden sounds. If you push on a panel it will flex because the cardboard will yield.

-- David

View Sawdust2's profile


1467 posts in 3507 days

#9 posted 03-08-2009 03:26 PM

Betsy, IMHO so long as the shelf is not more than 8-10” wide you do not need any interior support.
I made lots of shelves for my grandkids using 2×2 as the frame, 1/4” ply as the top and bottom, 2×2 as the support screwed to the wall.

Davcefai – the corregated cardboard is just as wide as the thickness of the door and it is put in on edge, not flat. No compression. At least that is what I was taught by Ian Kirby.

Don, I too will check out Tricel


-- No piece is cut too short. It was meant for a smaller project.

View Woodeo's profile


2 posts in 523 days

#10 posted 05-19-2015 08:33 PM

Try pre-built torsion box from Lowe’s, or see also:,,

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