Hey, So I have begun using placemaker to model a city scape. While it looks awesome, I am having trouble when i explode all and place on a flat base. The roads erase themselves and when working on them individually after running through a solid inspector, they do not work either. Any Ideas?
Thank You
Uhhh…
I mean, I’m sure I could formulate a guess here, as well as anyone, but it might be a tad easier to help you if you were to provide us a file 
we don’t need the whole file, but at least the faulty roads.
(you can either drag file here in the text box or through wetransfert & al)
As far as I know, very little of what Placemaker creates is 3D, much less a solid. You will have to do some push/pulling and grouping if you want solids.
Oh well. I was gonna check the file and give you an answer, ended up solving it. you might as well have the file 
Project for class.skp (5,8 Mo)
your roads are flat indeed. just faces, no volumes.
I copied the road group on the side, and exploded everything until there was only raw geometry. In theory, what you could do is erase all the small lines between the road bits so it would become one giant face, then pushpull it.
I used fredo6 push pull extension to simply make everything a bit thick - without having to clean it all - then grouped it all.
now, you can simply use the scale tool to squish it to the desired thickness. your file is in american units, it’s late, I’ve had a long day, I just made it thick. no specific size
Thank You! this has been the cause of many headaches this week im glad you were able to help me so much