It is enough to orient the faces correctly and the rendering is ok. Make sure that all faces are correctly oriented, white face outward when viewed in Monochrome.
Also, learn the basics about groups/components - https://learn.sketchup.com/track/sketchup-fundamentals-part-1
Hello mihai.s, I’ve just noticed your reply (I had to missed a notification) and thank you for your help! I appreciate it and it will save a lot (!) of time.
Yes, I know this model was a little mess - sorry, I usually explode a groups/components before rendering.
You’re welcome!
Why would you ever do that?
Hah, maybe it’s just a bad habit of when I had a really slow machine but it seemed to me that it rendered faster then. Was I wrong? 
There are very rare occasions when you need to explode a group / component. Otherwise, keep all the raw geometry grouped by elements.
I’ll do, thanks again 
Hello,
I have a sketchup model (2021 version) and am trying to create a sectional perspective using Vray. When I cut a section, on sketchUp it looks fine walls but my renders are not coming out right walls.
All faces correctly oriented, white to the outside? Are the walls, floors, etc grouped?
Possibly V-ray is ignoring the Section Fill option in SketchUp Styles. Maybe you have to put an actual face there, or use the clipping options given by v-ray.
Based on your images, I’m inclined to agree with @mihai.s. This looks more like an issue with reversed faces than section cuts. Look at the skp model in monochrome style and make sure the offending pieces of furniture are front side out. Renderers usually ignore back sides of faces. Painting textures in SketchUp can mask this flaw.
Yes all in goups
Considering that you can see down inside the wall in the render, it appears V-ray is ignoring the section fill. You could use TIG’s SectionCutFace to add an actual face at the section cut instead of using the section fill. You can then apply a color or material to the face. Alternatively you could use Group from Slice and manually create the face by editing the group.
This problem with the section occurs if not all the faces are correctly oriented (white outward).
Have you checked carefully and are you sure that everything is modeled correctly?
Hi, I have same issues as yours, I’ve tried everything, were you able to get a solution to this
Turning the “use object material” option off in section settings usually solves the problem…
Thank you so much…problem solved
I have noticed that if a scene has an active section plane but section cuts are turned off, the plane will still be visible in V-Ray. Making the section cut not active hides it.
I have the same problem too with a white spot on it and I have already reversed the faces on my object. how can i solve this? thank you!
Hereby I have uploaded my design.
Design Link
