[Crespyl]

I think it would be possible to slice the ladder exactly in half, down its length, right?

Each rung would go from a cylinder to a half-cylinder, but should still be rigidly connected to either side of the ladder all the same.

[Retra]

The problem is then you have two short ladders. You throw your two half ladders off the roof and they don't magically stand end-to-end for you. You have to cut with a twist to ensure the last rungs are entangled with each other so the half-ladders are hooked together. Then you can hang one off the other and reach the ground.

[Crespyl]

See I was envisioning one of these: http://www.bates.co.za/BMS_Product_Images/ROUND%20TUBE%20LAD...