Post #365941 by Swanky on Mon, Mar 10, 2008 12:54 PM

This image shows what I am referring to. These side beams are really what is holding the roof up. If you take these out, all that weight would have only one thing supporting it, that center vertical beam. The force is wanting to rip that roof line in half and flatten the roof like a pancake. These beams are what is really stopping that force, design-wise. A normal roof truss would be designed in triangles and that dissipates the forces throughout the structure. You can leave everythign open if you provide some sort of stop to hold the force of the roof angle. In the classic A-frame, the roof posts go all the way to the ground and there are structures on the outside of the footer that prevent the force from splitting the A in half. You have a few "trusses" here in the form of your vertical beams, and those are what is holding the whole thing together. But rather than bolting the roof beams into the cross beams and making a truss, you have the roof structure more or less sitting on top of the cross beams and you lose any sort of structural strength.

I'm not an engineer, I just play one on TC. Strength of materials will go a long way, but, a little bit more truss design will make the whole thing rock solid forever. Basically, it needs to be channeled, in gearhead talk.

Okay, let me focus and not ramble. If you bolt your roof beams to those cross beams to form a solid triangle, then you can take that center post out. It serves no purpose. Make a series of strong triangles of that structure, rather than haveing the roof sitting on top of the bolted together box as it is. Then you are using design strength and not material strength to hold it together.

Is that at all clear?

[ Edited by: Swanky 2008-03-10 13:38 ]