Tapered Roof screeds/insulation by modify sub-elements

[jp.vout]

We have a situation where we are trying to model the tapered screed within a roof build up to provide the necessary falls for drainage. 

The problem is that we can only make one layer variable in the roof build up to account for this. for example we have a build up of:

30mm MINIMUM screed (set to variable)

350mm Insulation

50mm Minimum pedestal/cavity (wants to be variable)

50mm paver ballast

what we want to create is a family/type that when the screed thickness increases, the gravel/cavity zone could reduce to allow the bottom and top of the roof to remain flat. 

Happy to explore other methods if 'modify sub-elements' doesn't work..... as long as it isn't model in place!

thanks for any help or thoughts. 

[barthbradley]

What about stacking roof types? Modeling each layer?

[jp.vout]

tried this and it won't allow you to 'thicken down' the variable layer if you have the screed. I'm not sure if there is a way of inverting the work plane that a floor is created in to allow the bottom to become the top and increase the thickness as we need it to. Albeit there would be some issues further down the line I'm sure.

[barthbradley · Accepted solution]

Join and Cut Geometry remove volume at the union.  Why can't you use those tools? Maybe some pictures would help. I might not be reading you right.  

....something like this?

[jp.vout]

Perfect. Thanks for the suggestion. I'm annoyed at myself for not thinking of this! Thanks!