Thanks for the question. Please see the attached file for a possible solution.
- I've added 3 sub-splines in one spline object, one to define the ridge, and the one each for the eaves.
- Add a Normalise Spline modifier and set the Knot Count to define the number of slats
- Add a Cross Section modifier to connect lines between the new vertices
- You can then use those with a simple RailClone object. To stop geometry from appearing on the longer splines you can use a Conditional operator
A sample file is attached.
I hope that helps,