Structural framing beam by curve


I’m creating a structural framing beam by curve.
I’m making intersections between surfaces and planes.
On the first surface dynamo place the beam upside the surface but on the second surface it’s underside the surface.
I tried with flip nomal direction but it’s don’t work…
The geometry of the surface change.
Do you have an idea where the proble come from ?

Thank you


The image you posted is too tiny
Could you split it into smaller ones please? Or attach the .dyn file


Here is my picture with a better size…

I played around but always had problems with NurbCurves, don’t know why I’m afraid ):

Is there another solution to do the same project ?