How to get Sloping top of a wall

I’m pretty new to Sketchup, and i’m now trying to draw a covered terrace from a wall with a sloping top.
So I can not figure out how I’ll cut the top of the wall so that the top follows the redCovered terrace.skp (112.2 KB)
surface in the drawing (Sketchup 2014)

Start by exploding the wall group/component (or you can move the plane inside the group/component - your choice). Then:

Image 1. Select the wall and the angle plane, and choose Intersect Faces > With Selection

Image 2. The angle lines will now be cut into your walls.

Image 3. Double-click the top surface of the wall and delete.

Image 4. Just draw a line at the back of the model to complete the wall and top surface again.

As an alternative, you can use Edit>Cut to cut the red rectangle (the cutting plane) to the clipboard, open the wall group for editing and paste the cutting plane in place. Then run intersect. This method results in a portion of the cutting plane becoming the top of the wall. Extruding the wall above the cut makes it easier to select the unneeded part for erasure.

This method also works when the cutting surfaces isn’t flat so it’s useful to know. And it doesn’t involve exploding the wall group. You shouldn’t need to explode groups or components to edit them.

neither are required steps, just click into the group and ‘intersect with model’…

or do what dave suggests…

john

Thanks for all replies. I used the method DaveR describe and it worked fine.