Material layer grapic representation gets solid when cutting with void

[benschilders]

Hi all, 

We have a problem that occurs from time to time when cutting floors or roofs with voids (in place model).

Problem: (added a video of the problem)
When cutting a roof with a model in place void sometimes the layer representation on sections goes crazy
representing it as a solid instead of layers roof/floor. 
(the material gets chosen by the category material that is set in object styles)

Sometimes it helps to leave 1mm of a certain layer intact (not cutting it with the void). 
(For example, when cutting insulation at the sides of a roof leave 1mm of insulation 
then this problem does not occur). 

Does anyone had this happen before and maybe found a soulution/work arround ? 
(better then to figure out where to leave 1mm of material intact for it to represent as layers)

PS: 
I did search the forums for a soulution but couldnt find anyone with similar problems,
if you do know a forum with a soulution feel to link it here. 

Kind regards,
Ben

[barthbradley · Accepted solution]

Try changing one of the Layers in the Assembly to Variable.  The Structure one.   

[ToanDN]

Join geometry the walls with a mass then hide the mass.

[benschilders]

@barthbradley  Thanks ! , In my case this did the job ! So will remember this one for the future.

@ToanDN  Thanks, i will remember this as a last resort option. 
                    I guess one would have to use a filter or subcategories to hide the mass for 
                    the most practical use case of this soulution. 

Thanks to both of you for sharing your knowlegde