I am testing the trial at the moment and I know that the slab tool is under development. Given that the void / penetration tools are very unstable (as in resetting any slab mods) can one simply create voids in the slab using traditional SK push pull methods. I have, for example, a ramped car park slab (I know the ramp function is also under development) that intersects with an escape stair. Would traditional SK construction methods have any effect on take off function, etc.
Like all of our tools you can manually edit the geometry inside the groups to exactly how you need it using traditional SketchUp functions and tools. However, I would recommend only doing manual edits once you no longer need to change any of the parameters in the Slab Tool dialogue or using either the Penetration, Void or Recess Tools , if you can help it, otherwise any manual edit will be removed.
It shouldn’t have any affect on the takeoff as long as the slab is whole and there is no extra geometry in the group. You can check to see if it’ll estimate by double-clicking on the slab to go inside the group, then select the slab and check the Volume field in Entity Info. If the Volume field doesn’t appear then there is an error and it won’t estimate.
Basically you can do manual edits on concrete provided the slab is manifold. If you delete an edge or a face PlusSpec can no longer quantify the cubic capacity. Think of it like a bottle, if you remove the base or lid liquid will spill. If the Sketchup geometry is not enclosed it will also spill. I use manual edits all the time however the new slab tool that will be with you very soon has had a lot of work done to it so I am sure this will help with your workflow.
By the way did you know you can create concrete from a sloping face? It is great for doing driveways.