Multi-plane roofs can not have a pitch less than 1.75% (1°).
However a single plane roof (which would be much easier to use here) can be flat or even have a negative slope.
So use the ridges as your pivot lines and set a -1.5% slope.
Then manipulate the shape just as you would a polygon or you can select one roof and CTRL click the edge of an adjoining roof to automatically trim that edge into the correct position (that's the way we had to do it before multi-plane roofs).
If you know the heights of your ridges then use that straight away when placing the roofs.
If not don't worry, just place the roof and figure out its shape, then elevate it to the height you want afterwards.
Barry.
One of the forum moderators.
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