Torsion Box Shelving - Wide

[mrmwink]

Hi,

I am reletively new to the idea of a Torsion Box, having read up it seems like a great way to create a good solid shelf giving the floating illusion.

I am looking to implement the idea in our spare room and want a single shelf spanning the entire width of the room, for the sake of the forum lets says it's 3m wide (its actually a little less)

What I need to understand is if this is simply going to be too wide for a Torsion Box system made of Timber / MDF to be able to take any weight.

It is actually only going to be used for photography props so nothing like large heavy books but it does obviously need to be secure.

I am able to have a solid fixing on the rear beam to an external wall, the side supports 1 will be again on an external wall the other on a partition which I was looking to fix using Piranha type fixing which are currently holding a pretty heafty glass bathroom cabinet (20kg) without any drama!

I have been using the following link as the base for the design but wandered if anyone has experience of this shelf type over such a distance, and if so what they would recommend?

http://www.woodworkersinstitute.com/page.asp?p=705

Cheers

Mike

 

[foxhole]

I have made these for 2m shelving in alcove , for long shelves the problem is likely to be sagging or twisting of the middle front edge if they are too deep [you did not mention depth, front to back] or if they are too thin, I made mine 60mm which worked well.
Only had 20mm for the rear slot as I used 20mm veneered mdf for the shelf sandwich and 20mm batten to separate the two halves. An alternative to batten on the wall if you need a narrower shelf is aluminium C channel screwed to the wall as it's strong for it's dimensions than timber.