Hello Raja, 

It seems with your complex surface that you are intending to create planar ribs based on the surface's isocurves. The process seems to yield the twisted result you are experiencing. If it is possible to contour the surface in more of a traditional waffle fashion a desirable rationalization of the surface is more easily achieved. (See attached)However, if you wish to extrude the curves planar from their isocurves, I am sure there is a way to achieve that as well. Also, you can adjust the contours in the attached definition to achieve a diagonal waffle as well. 

Hope this helps, 

Erik

If I duplicate most of your script after using Offset using a negative offset to avoid artifacts of scrunching up rather than expansion, I get related lines for both surfaces, that might be helpful:

Otherwise, the Bowerbird plugin has a Waffle component for this, which takes a solid as a mesh and automatically makes flat strips, or you can do it with more control with the Bowerbird Section component, so search for that too, here. You can make a solid mesh by lofting the extracted edges of each surface and join to create a solid first, or by just making the surface into a single mesh surface then into a thickened closed mesh using Weaverbird's wbThicken.