Polyline Ridge Cap

[billemery]

Peter,
It's not necessary to create a symbol here. Just draw the profile that you need, select it, and add it to the library as a molding profile. Once this is done you can select the profile for your 3D molding polyline.

The advantage of 3D molding polyline is that the molding will follow the X, Y, and Z coordinates that you have asigned to it, which in this case is very easy as we can just snap to the roof profile and then add the Z coordinates.

Symbols are quite adaptable and can be stretched in all axis, but the distinct advantage of the molding polyline here is ease of use, and the ability to control the miters.