02-11-2016, 03:26 PM
From what I have read, including some of the concepts of John Allen (Gorre & Depheted), you have to actually build a structure or a car with the swayback built into the construction. Building it normally and then trying to change it leads to breakage, frustration and certain words we cannot talk about here! 
So for a swayback roof, once you have the "sway" figured out, you would then need to proceed with framing members already adapted to the degree of sag or curvature you want, and then adapt your roofing material to fit.
If the four corners of the roof are stable, but only the peak is to receive this treatment - a sag in the middle, for example - this is relatively easy. Make a foam model of the triangular roof and file down the middle to assume the curve or sag you want and then roof it over. This will give you a strong, stable structure you can handle, move, clear or whatever, and your "sag" will remain where you put it, and no one will see the foam after the actual roofing goes on. With a little practice, you should be able to make it sag in more than one direction using this method.
So for a swayback roof, once you have the "sway" figured out, you would then need to proceed with framing members already adapted to the degree of sag or curvature you want, and then adapt your roofing material to fit.
If the four corners of the roof are stable, but only the peak is to receive this treatment - a sag in the middle, for example - this is relatively easy. Make a foam model of the triangular roof and file down the middle to assume the curve or sag you want and then roof it over. This will give you a strong, stable structure you can handle, move, clear or whatever, and your "sag" will remain where you put it, and no one will see the foam after the actual roofing goes on. With a little practice, you should be able to make it sag in more than one direction using this method.